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Exhibit MSD 37B - MSD Combined Sewer Overflow Long-Term Control Plan (LTCP)Exhibit MSD 37B https://www.stlmsd.com/what-we-do/taking-good-care/sewer-overflows This report is formatted for double-sided printing. Revised February 2011 This page is blank to facilitate double-sided printing. Acknowledgments This Combined Sewer Overflow Long-Term Control Plan Update report was prepared for the Metropolitan St. Louis Sewer District by a team consisting of District staff and consultants. The principal consultants providing support to MSD in the preparation of the Long-Term Control Plan are: • Jacobs Engineering Group • Galardi Rothstein Group • Greeley and Hansen LLC • Limno-Tech, Inc. • Shook, Hardy & Bacon LLP • Vector Communications This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS i February 2011 TABLE OF CONTENTS Executive Summary Section 1 – Introduction 1.1 Overview and Purpose ...................................................................................................................1-1 1.2 National Perspective.......................................................................................................................1-4 1.3 Historical Background of MSD’s Combined Sewer System.........................................................1-4 1.4 Long-Term Control Plan – Planning Approach.............................................................................1-6 Section 2 – Regulatory Background 2.1 General...........................................................................................................................................2-1 2.2 CSO Control Strategy.....................................................................................................................2-1 2.3 CSO Control Policy........................................................................................................................2-1 2.4 Technology-Based Requirements ..................................................................................................2-2 2.4.1 Federal Interpretation...........................................................................................................2-2 2.4.2 State Interpretation...............................................................................................................2-2 2.4.3 MSD Response.....................................................................................................................2-2 2.5 Water Quality-Based Requirements...............................................................................................2-3 2.6 NPDES Permits (Missouri State Operating Permits).....................................................................2-3 2.7 Phased Long-Term Control Plan....................................................................................................2-4 2.8 EPA Section 308 Request for Information and Subsequent Litigation..........................................2-4 2.9 Consent Decree ..............................................................................................................................2-4 Section 3 – Existing Conditions 3.1 Combined Sewer Area ...................................................................................................................3-1 3.1.1 General Description..............................................................................................................3-1 3.1.2 Political Subdivisions...........................................................................................................3-4 3.1.3 Population.............................................................................................................................3-5 3.1.4 Pollution Sources and Factors Affecting Runoff .................................................................3-6 3.2 Sewer Systems................................................................................................................................3-8 3.2.1 Bissell Point Combined Sewer System................................................................................3-8 3.2.2 Lemay Combined Sewer System .......................................................................................3-12 3.2.3 Interrelationships of Systems.............................................................................................3-17 3.2.4 CSO Operational Modes ....................................................................................................3-18 3.2.5 Treatment Plants and Pump Stations..................................................................................3-19 3.2.6 CSO Controls Implemented During Planning....................................................................3-22 3.3 Receiving Waters .........................................................................................................................3-26 3.3.1 Descriptions........................................................................................................................3-27 3.3.2 Water Quality Standards ....................................................................................................3-28 3.3.3 Existing Water Quality.......................................................................................................3-32 3.3.4 Flow Regime......................................................................................................................3-45 3.3.5 Sensitive Waters.................................................................................................................3-45 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS ii February 2011 Section 4 – Sewer System Characterization, Monitoring & Modeling 4.1 Introduction....................................................................................................................................4-1 4.2 Previous Sewer System Characterization, Monitoring, and Modeling..........................................4-1 4.3 CSO and Diversion Structure Physical Attribute Data Verification..............................................4-2 4.4 Monitoring Program.......................................................................................................................4-2 4.4.1 Flow Monitoring Program....................................................................................................4-2 4.4.2 Rainfall Monitoring Program...............................................................................................4-5 4.4.3 Wastewater Sampling...........................................................................................................4-5 4.5 Event Mean Concentrations...........................................................................................................4-7 4.6 Collection System Modeling Program...........................................................................................4-8 4.6.1 Modeling Software Selection...............................................................................................4-8 4.6.2 Model Development.............................................................................................................4-9 4.6.3 Model Description and Limitations....................................................................................4-10 4.6.4 Model Calibration and Verification ...................................................................................4-13 4.7 Model Results...............................................................................................................................4-16 Section 5 – Receiving Stream Characterization, Monitoring and Modeling 5.1 Introduction....................................................................................................................................5-1 5.2 Previous Receiving Water Characterization, Monitoring and Modeling.......................................5-1 5.3 Receiving Water Monitoring..........................................................................................................5-1 5.3.1 Wet Weather Surveys...........................................................................................................5-2 5.3.2 Continuous Monitoring........................................................................................................5-4 5.3.3 Tributary and Upstream Boundary Sampling ......................................................................5-5 5.4 Updates to Hydrologic and Hydraulic Models...............................................................................5-7 5.4.1 Lower River Des Peres.........................................................................................................5-7 5.4.2 Maline Creek......................................................................................................................5-15 5.4.3 Upper River Des Peres.......................................................................................................5-18 5.5 Updates to Water Quality Models................................................................................................5-22 5.5.1 Photosynthesis and Respiration..........................................................................................5-22 5.5.2 Multiple Sources of Bacteria and CBOD...........................................................................5-22 5.6 Lower River Des Peres Calibration and Validation.....................................................................5-22 5.6.1 Calibration Event: October 2007........................................................................................5-24 5.6.2 Validation Event: November 2007.....................................................................................5-32 5.7 Maline Creek Calibration and Validation ....................................................................................5-39 5.7.1 Calibration Event: October 2007........................................................................................5-40 5.7.2 Validation Event: November 2007.....................................................................................5-47 5.8 Upper River Des Peres Calibration and Validation .....................................................................5-54 5.8.1 Calibration Event: September 2008 ...................................................................................5-55 5.8.2 Validation Event: June 2008..............................................................................................5-62 5.9 Calibration of Photosynthesis and Respiration Process to Continuous Dissolved Oxygen Data ...5-69 Section 6 – Estimated Pollutant Loadings and Predicted Water Quality 6.1 Determination of Typical Year ......................................................................................................6-1 6.2 Lower and Middle River Des Peres ...............................................................................................6-3 6.3 Maline Creek..................................................................................................................................6-7 6.4 Upper River Des Peres...................................................................................................................6-9 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS iii February 2011 Section 7 – CSO Control Options and Screening 7.1 Introduction....................................................................................................................................7-1 7.2 CSO Control Goals.........................................................................................................................7-1 7.3 Level 1 Screening...........................................................................................................................7-2 7.3.1 Technology Screening..........................................................................................................7-2 7.3.2 Development of Integrated Control Alternatives.................................................................7-6 7.3.3 Maline Creek – Integrated Control Alternatives..................................................................7-6 7.3.4 Gingras Creek – Integrated Control Alternatives...............................................................7-10 7.3.5 Mississippi River – Integrated Control Alternatives..........................................................7-12 7.3.6 Upper River Des Peres – Integrated Control Alternatives.................................................7-15 7.3.7 River Des Peres Tributaries – Integrated Control Alternatives..........................................7-17 7.3.8 Lower and Middle River Des Peres – Integrated Control Alternatives .............................7-19 7.4 Level 2 Screening.........................................................................................................................7-21 7.4.1 Bases of Design of Integrated Control Alternatives...........................................................7-21 7.4.2 Bases for Cost Estimates....................................................................................................7-22 7.4.3 Alternatives Screening Process..........................................................................................7-23 7.4.4 Level 2 Screening Results..................................................................................................7-23 Section 8 – Alternatives Evaluation 8.1 Introduction....................................................................................................................................8-1 8.2 Level 3 Screening...........................................................................................................................8-1 8.2.1 Bases of Design of Integrated Control Alternatives.............................................................8-2 8.2.2 Bases for Cost Estimates......................................................................................................8-2 8.2.3 Determination of CSO Control Benefits..............................................................................8-3 8.2.4 Screening Procedures...........................................................................................................8-3 8.3 Level 3 Screening Results..............................................................................................................8-3 8.3.1 Maline Creek........................................................................................................................8-4 8.3.2 Gingras Creek.......................................................................................................................8-8 8.3.3 Mississippi River................................................................................................................8-13 8.3.4 Upper River Des Peres.......................................................................................................8-16 8.3.5 River Des Peres Tributaries................................................................................................8-18 8.3.6 Lower and Middle River Des Peres ...................................................................................8-23 8.4 Selected Alternative .....................................................................................................................8-27 8.4.1 Scenario 1 – Complete Elimination ...................................................................................8-28 8.4.2 Scenario 2 – “Knee-of-Curve” Everywhere.......................................................................8-29 8.4.3 Scenario 3 – “Knee-of-Curve” on Urban Streams plus Enhanced Green Program on Mississippi River...............................................................8-30 8.4.4 Scenario 4 – Uniform Minimum Level of Control ............................................................8-31 8.4.5 Scenario 5 – Graduated Control on Urban Streams plus Enhanced Green Program on Mississippi River...............................................................8-32 8.4.6 System-Wide Benefits of Control Scenarios......................................................................8-33 8.4.7 Selected CSO Control Scenario .........................................................................................8-34 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS iv February 2011 Section 9 – Public Participation 9.1 Introduction....................................................................................................................................9-1 9.2 Research.........................................................................................................................................9-1 9.3 Situational Analysis – Understanding Public Interests..................................................................9-2 9.3.1 Stakeholder Interviews.........................................................................................................9-2 9.4 Outreach & Education....................................................................................................................9-4 9.4.1 Project Branding & Planning Goals.....................................................................................9-4 9.4.2 FAQ, Fact Sheet, Brochure..................................................................................................9-5 9.4.3 Video....................................................................................................................................9-5 9.4.4 Website.................................................................................................................................9-5 9.4.5 Community Presentations ....................................................................................................9-6 9.4.6 Media....................................................................................................................................9-7 9.5 Public Input & Involvement...........................................................................................................9-8 9.5.1 Stakeholder Advisory Committee (SAC).............................................................................9-8 9.5.2 Telephone Surveys.............................................................................................................9-11 9.5.3 Open Houses ......................................................................................................................9-15 9.5.4 Voicemail & Email Address ..............................................................................................9-20 9.6 Future Public Participation...........................................................................................................9-21 Section 10 – Financial Capability Assessment 10.1 Introduction..................................................................................................................................10-1 10.2 Legislative and Regulatory Intent................................................................................................10-2 10.3 MSD’s Financial Capability Assessment.....................................................................................10-3 10.3.1 Introduction......................................................................................................................10-3 10.3.2 Local Considerations........................................................................................................10-4 10.3.3 MSD Financial Planning..................................................................................................10-6 10.3.4 Holistic Evaluation of Program Costs..............................................................................10-9 10.3.5 Portfolio Management......................................................................................................10-9 10.3.6 CSO Control Policy Compliance / Enhancements to Current Guidance.......................10-11 10.4 Conclusions................................................................................................................................10-11 Section 11 – Selected Plan 11.1 Introduction..................................................................................................................................11-1 11.2 Selected Controls..........................................................................................................................11-1 11.2.1 System-wide Controls......................................................................................................11-3 11.2.2 Controls Specific to Maline Creek CSOs.........................................................................11-4 11.2.3 Controls Specific to Gingras Creek CSOs .......................................................................11-5 11.2.4 Controls Specific to Upper River Des Peres CSOs..........................................................11-6 11.2.5 Controls Specific to River Des Peres Tributaries CSOs..................................................11-7 11.2.6 Controls Specific to Lower and Middle River Des Peres CSOs......................................11-9 11.2.7 Controls Specific to Mississippi River CSOs ................................................................11-10 11.2.8 Expandability .................................................................................................................11-11 11.2.9 Justification for Excess Flow Treatment at Bissell Point and Lemay Treatment Plants ..11-12 11.3 Water Quality Benefits of Selected Controls.............................................................................11-19 11.3.1 Pollutant Load Reductions with the Selected Controls..................................................11-19 11.3.2 Summary of Water Quality Impacts of CSOs................................................................11-20 11.3.3 Contributing Factors to Dissolved Oxygen Impairments...............................................11-21 11.3.4 Review and Revision of Water Quality Standards.........................................................11-24 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS v February 2011 Section 11 – Selected Plan (continued) 11.4 Implementation Schedule...........................................................................................................11-24 11.4.1 Prioritization of Controls................................................................................................11-25 11.4.2 Implementation Components .........................................................................................11-26 11.4.3 Scheduling Considerations.............................................................................................11-26 11.5 Post-Construction Compliance Monitoring Program.................................................................11-27 11.5.1 Program Elements..........................................................................................................11-28 11.5.2 Control Program Performance Measures.......................................................................11-29 Section 12 – Green Infrastructure Program 12.1 Introduction..................................................................................................................................12-1 12.1.1 Reasons for Incorporating Green Infrastructure in MSD’s LTCP...................................12-1 12.1.2 The Role of Green Infrastructure in MSD’s LTCP..........................................................12-4 12.2 Potential Green Infrastructure Opportunities in MSD’s CSS Area..............................................12-4 12.3 The St. Louis Green Infrastructure Program................................................................................12-6 12.3.1 MSD as a Green Infrastructure Leader.............................................................................12-6 12.3.2 Public Education and Outreach........................................................................................12-6 12.3.3 Rain Barrel Program.........................................................................................................12-7 12.3.4 Ongoing Projects..............................................................................................................12-8 12.3.5 Stormwater Retrofitting Green Infrastructure Project......................................................12-9 References Acronyms List of Appendices Appendix A Combined Sewer System Schematics Appendix B Hydraulic Model Results for Typical Year Appendix C Updated Comparisons of Data to Water Quality Criteria Appendix D Wet Weather Survey Sampling Results Appendix E Summary of Continuous Monitoring Data Appendix F SWMM5 Model Input Data Appendix G Description of Photosynthesis & Respiration Algorithm Appendix H Technologies Matrix Appendix I Level 3 Alternatives Analysis – Cost Summaries Appendix J Level 3 Alternatives Analysis – Cost-Benefit Data Appendix K Stakeholder Interviews Appendix L Community Presentations Appendix M Stakeholder Advisory Committee Appendix N Telephone Surveys Appendix O Open Houses Appendix P Voicemail & Email Logs Appendix Q MSD’s Green Infrastructure Program Appendix R Consent Decree Enforceable Provisions Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS vi February 2011 List of Tables No. Title Page 2-1 The Nine Minimum Controls for CSOs....................................................................................2-2 3-1 Municipalities in the Combined Sewer Area............................................................................3-5 3-2 Land Use in the Combined Sewer Area....................................................................................3-7 3-3 Average and Selected Typical Year St. Louis Rainfall Characteristics....................................3-8 3-4 Bissell Point CSO Outfalls......................................................................................................3-11 3-5 Lemay CSO Outfalls...............................................................................................................3-14 3-6 Benefits of Overflow Regulation Systems..............................................................................3-23 3-7 Benefits of Treatment Plant and Pump Station Improvements...............................................3-23 3-8 Benefits of Skinker-McCausland Tunnel................................................................................3-24 3-9 Benefits of Industrial Waste Separations................................................................................3-25 3-10 Combined Sewer Separations.................................................................................................3-25 3-11 Benefits of Sewer Separations................................................................................................3-25 3-12 Stream Classifications and Designated Uses..........................................................................3-30 3-13 Water Quality Criteria for Ammonia and Dissolved Oxygen ................................................3-32 3-14 Water Quality Criteria for E. coli ...........................................................................................3-32 4-1 Flow Meter Summary...............................................................................................................4-3 4-2 Wastewater Monitoring Summary............................................................................................4-6 4-3 Wastewater Quality Parameters for Analysis...........................................................................4-7 4-4 Event Mean Concentrations......................................................................................................4-8 4-5 Hydraulic Model Results for Typical Year (2000).................................................................4-16 5-1 Sample Locations for Wet Weather Surveys............................................................................5-2 5-2 Water Quality Parameters Analyzed in Wet Weather Survey Sampling..................................5-4 5-3 Summary of Wet Weather Events.............................................................................................5-4 5-4 Summary of Continuous Monitoring Locations.......................................................................5-5 5-5 Locations for Tributary and Upstream Boundary Sampling.....................................................5-6 5-6 Statistical Summary of Upstream Boundary Sampling............................................................5-7 5-7 USGS Gages for Calibration of Hydrologic Models................................................................5-8 5-8 Kinetic Parameters for the Lower River Des Peres EUTRO Model ......................................5-23 5-9 CSO and Storm Water Pollutant Concentrations for the Lower River Des Peres..................5-24 5-10 Kinetic Parameters for the Maline Creek EUTRO Model......................................................5-39 5-11 CSO and Storm Water Pollutant Concentrations for Maline Creek.......................................5-40 5-12 Kinetic Parameters for the Upper River Des Peres EUTRO Model.......................................5-54 5-13 CSO and Storm Water Pollutant Concentrations for the Upper River Des Peres ..................5-55 6-1 Probabilities Associated with Maximum Year 2000 Backwater Event....................................6-2 6-2 Modeled Pollutant Loads to River Des Peres in Typical Year.................................................6-3 6-3 Modeled Pollutant Loads to Maline Creek in Typical Year.....................................................6-7 6-4 Modeled Pollutant Loads to Upper River Des Peres in Typical Year......................................6-9 7-1 Technology Screening Matrix...................................................................................................7-2 7-2 Integrated Control Alternatives - Maline Creek.......................................................................7-8 7-3 Integrated Control Alternatives - Gingras Creek....................................................................7-11 7-4 Integrated Control Alternatives - Mississippi River...............................................................7-14 7-5 Integrated Control Alternatives - Upper River Des Peres ......................................................7-16 7-6 Integrated Control Alternatives - River Des Peres Tributaries...............................................7-17 7-7 Integrated Control Alternatives - Lower and Middle River Des Peres...................................7-20 7-8 Calculation Procedure for Construction Cost Opinions..........................................................7-23 7-9 Alternative Screening Criteria................................................................................................7-23 7-10 Maline Creek Level 2 Analysis Cost Summary......................................................................7-24 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS vii February 2011 List of Tables (continued) No. Title Page 7-11 Gingras Creek Level 2 Analysis Cost Summary....................................................................7-25 7-12 Mississippi River Level 2 Analysis Cost Summary ...............................................................7-27 7-13 Upper River Des Peres Level 2 Analysis Cost Summary.......................................................7-28 7-14 River Des Peres Tributaries Level 2 Analysis Cost Summary...............................................7-29 7-15 Lower and Middle River Des Peres Level 2 Analysis Cost Summary...................................7-30 8-1 Calculation Procedure for Level 3 Cost Opinions....................................................................8-3 8-2 Level 3 Evaluation of Maline Creek Alternatives ....................................................................8-8 8-3 Level 3 Evaluation of Gingras Creek Alternatives.................................................................8-12 8-4 Level 3 Evaluation of Mississippi River Alternatives............................................................8-15 8-5 Level 3 Evaluation of Upper River Des Peres Alternatives ...................................................8-18 8-6 Level 3 Evaluation of River Des Peres Tributaries Alternatives............................................8-22 8-7 Level 3 Evaluation of Lower and Middle River Des Peres Alternatives................................8-27 8-8 CSO Control Scenario 2..........................................................................................................8-29 8-9 CSO Control Scenario 3..........................................................................................................8-30 8-10 CSO Control Scenario 4..........................................................................................................8-31 8-11 CSO Control Scenario 5..........................................................................................................8-32 9-1 CRHC Website Statistics..........................................................................................................9-5 9-2 Presentation Comments by Type..............................................................................................9-6 9-3 SAC Organizations...................................................................................................................9-8 9-4 SAC Waterway Priorities..........................................................................................................9-9 9-5 Stakeholder Advisory Committee's CSO Control Scenario Prioritization .............................9-10 9-6 Survey Completion.................................................................................................................9-15 9-7 Open House Waterway Priorities............................................................................................9-17 9-8 Waterways of Highest Concern or Importance.......................................................................9-18 9-9 Waterways of Least Concern or Importance ..........................................................................9-18 9-10 Preferred Level of Control......................................................................................................9-18 9-11 Stewardship Values.................................................................................................................9-19 9-12 Additional MSD Actions to Improve Water Quality..............................................................9-19 9-13 Additional Public Actions to Improve Water Quality............................................................9-20 9-14 Event Satisfaction...................................................................................................................9-20 9-15 On-line Event Satisfaction......................................................................................................9-20 10-1 Long-Range Financial Projection Model - Forecast Components..........................................10-6 10-2 Long-Range Financial Projection Model - Selected Key Assumptions .................................10-7 11-1 Selected Long-Term Control Plan Components.....................................................................11-2 11-2 CSO Separation Projects Along River Des Peres Tributaries ................................................11-8 11-3 Flow Blending Alternatives – Lemay Treatment Plant........................................................11-18 11-4 Modeled Pollutant Loads Resulting from the Selected Controls in a Typical Year.............11-20 11-5 Projected LTCP Performance...............................................................................................11-28 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS viii February 2011 List of Figures No. Title Page 1-1 MSD's Combined Sewer Area..................................................................................................1-1 1-2 Combined Sewer System Operation During Dry and Wet Weather.........................................1-2 1-3 MSD's Permitted Combined Sewer Overflow Outfalls............................................................1-3 1-4 Location of Communities with Combined Sewer Overflows...................................................1-4 1-5 Channelized River Des Peres....................................................................................................1-4 1-6 MSD's Progress in Reducing CSO Volume 1954 to 2009........................................................1-5 3-1 Combined Sewer and Tributary Areas......................................................................................3-1 3-2 Bissell Point Combined Sewer Area.........................................................................................3-2 3-3 Lemay Combined Sewer Area..................................................................................................3-3 3-4 Municipalities in the Combined Sewer Area............................................................................3-4 3-5 Bissell Point Service Area ........................................................................................................3-9 3-6 Typical Bissell Point Combined Sewer Subsystem................................................................3-10 3-7 Lemay Service Area................................................................................................................3-12 3-8 Typical Lemay Combined Sewer Subsystem.........................................................................3-14 3-9 CSO Operation - Low River Mode.........................................................................................3-18 3-10 CSO Operation - ORS Mode..................................................................................................3-19 3-11 CSO Operation - Flood Mode.................................................................................................3-19 3-12 Bissell Point Treatment Plant Schematic................................................................................3-20 3-13 Lemay Treatment Plant Schematic.........................................................................................3-21 3-14 CSO Receiving Waters...........................................................................................................3-26 3-15 Total Ammonia Levels in Maline Creek and the Upper River Des Peres..............................3-33 3-16 Total Ammonia Levels in the Middle River Des Peres and Tributaries.................................3-34 3-17 Total Ammonia Levels in the Lower River Des Peres and Gravois Creek............................3-35 3-18 Dissolved Oxygen Levels in the Mississippi River................................................................3-36 3-19 Dissolved Oxygen Levels in Maline Creek and the Upper River Des Peres..........................3-37 3-20 Dissolved Oxygen Levels in the Middle River Des Peres and Tributaries.............................3-38 3-21 Dissolved Oxygen Levels in the Lower River Des Peres and Gravois Creek........................3-39 3-22 E. coli Levels in the Mississippi River...................................................................................3-41 3-23 E. coli Levels in Maline Creek and the Upper River Des Peres.............................................3-42 3-24 E. coli Levels in the Middle River Des Peres and Tributaries................................................3-43 3-25 E. coli Levels in the Lower River Des Peres and Gravois Creek...........................................3-44 3-26 Theoretical Distance to Complete Mix for Side Discharges to the Mississippi River near St. Louis, MO........................................................................................................3-47 4-1 Flow Meter and Rain Gage Locations......................................................................................4-3 4-2 Wastewater Monitoring Locations............................................................................................4-6 4-3 Modeled Sub-catchments........................................................................................................4-11 4-4 Extents of Hydraulic Models for Lemay and Bissell Point Service Areas.............................4-12 4-5 Sensitivity of CSO Flow Capture to River Stage....................................................................4-13 4-6 Tributary Areas of Flow Meters Used for Model Calibration................................................4-14 4-7 Summary of Model Calibration and Verification Results ......................................................4-15 5-1 2007-2008 Monitoring Program: Lower and Middle River Des Peres.....................................5-3 5-2 2007-2008 Monitoring Program: Maline Creek.......................................................................5-3 5-3 2007-2008 Monitoring Program: Upper River Des Peres........................................................5-4 5-4 Summary of Tributary and Upstream Boundary Sampling......................................................5-6 5-5 Configuration of SWMM5 Model of the Lower and Middle River Des Peres ........................5-8 5-6 Configuration of FEQ/EUTRO Model of the Lower and Middle River Des Peres................5-10 5-7 SWMM5 Calibration to 2007 Events: Deer Creek at Ladue..................................................5-11 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS ix February 2011 List of Figures (continued) No. Title Page 5-8 SWMM5 Calibration to 2007 Events: Deer Creek at Maplewood.........................................5-12 5-9 SWMM5 Calibration to 2007 Events: MacKenzie Creek......................................................5-13 5-10 SWMM5 Calibration to 2007 Events: Gravois Creek............................................................5-14 5-11 Configuration of SWMM5 Model of Maline Creek...............................................................5-15 5-12 Configuration of FEQ/EUTRO Model of Maline Creek........................................................5-16 5-13 SWMM5 Calibration to 2007 Events: Maline Creek at Bellefontaine Neighbors .................5-17 5-14 Configuration of SWMM5 Model of the Upper River Des Peres..........................................5-18 5-15 Configuration of FEQ/EUTRO Model of the Upper River Des Peres...................................5-19 5-16 SWMM5 Calibration 2007/2008 Events: Upper River Des Peres at Purdue.........................5-20 5-17 SWMM5 Calibration 2007/2008 Events: Upper River Des Peres Tributary at Pagedale......5-21 5-18 Lower River Des Peres: Dissolved Oxygen Calibration, October 2007 Event ......................5-26 5-19 Lower River Des Peres: E. coli Calibration, October 2007 Event..........................................5-27 5-20 Lower River Des Peres: Ammonia Calibration, October 2007 Event....................................5-28 5-21 Lower River Des Peres: Organic Nitrogen Calibration, October 2007 Event........................5-29 5-22 Lower River Des Peres: Nitrate Calibration, October 2007 Event.........................................5-30 5-23 Lower River Des Peres: CBOD5 Calibration, October 2007 Event.......................................5-31 5-24 Lower River Des Peres: Dissolved Oxygen Validation, November 2007 Event ...................5-33 5-25 Lower River Des Peres: E. coli Validation, November 2007 Event.......................................5-34 5-26 Lower River Des Peres: Ammonia Validation, November 2007 Event.................................5-35 5-27 Lower River Des Peres: Organic Nitrogen Validation, November 2007 Event.....................5-36 5-28 Lower River Des Peres: Nitrate Validation, November 2007 Event......................................5-37 5-29 Lower River Des Peres: CBOD5 Validation, November 2007 Event....................................5-38 5-30 Maline Creek: Dissolved Oxygen Calibration, October 2007 Event......................................5-41 5-31 Maline Creek: E. coli Calibration, October 2007 Event.........................................................5-42 5-32 Maline Creek: Ammonia Calibration, October 2007 Event ...................................................5-43 5-33 Maline Creek: Organic Nitrogen Calibration, October 2007 Event.......................................5-44 5-34 Maline Creek: Nitrate Calibration, October 2007 Event........................................................5-45 5-35 Maline Creek: CBOD5 Calibration, October 2007 Event......................................................5-46 5-36 Maline Creek: Dissolved Oxygen Validation, November 2007 Event...................................5-48 5-37 Maline Creek: E. coli Validation, November 2007 Event......................................................5-49 5-38 Maline Creek: Ammonia Validation, November 2007 Event ................................................5-50 5-39 Maline Creek: Organic Nitrogen Validation, November 2007 Event ....................................5-51 5-40 Maline Creek: Nitrate Validation, November 2007 Event .....................................................5-52 5-41 Maline Creek: CBOD5 Validation, November 2007 Event ...................................................5-53 5-42 Upper River Des Peres: Dissolved Oxygen Calibration, September 2008 Event...................5-56 5-43 Upper River Des Peres: E. coli Calibration, September 2008 Event......................................5-57 5-44 Upper River Des Peres: Ammonia Calibration, September 2008 Event................................5-58 5-45 Upper River Des Peres: Organic Nitrogen Calibration, September 2008 Event....................5-59 5-46 Upper River Des Peres: Nitrate Calibration, September 2008 Event.....................................5-60 5-47 Upper River Des Peres: CBOD5 Calibration, September 2008 Event...................................5-61 5-48 Upper River Des Peres: Dissolved Oxygen Validation, June 2008 Event .............................5-63 5-49 Upper River Des Peres: E. coli Validation, June 2008 Event.................................................5-64 5-50 Upper River Des Peres: Ammonia Validation, June 2008 Event...........................................5-65 5-51 Upper River Des Peres: Organic Nitrogen Validation, June 2008 Event...............................5-66 5-52 Upper River Des Peres: Nitrate Validation, June 2008 Event................................................5-67 5-53 Upper River Des Peres: CBOD5 Validation, June 2008 Event..............................................5-68 5-54 Comparison of Model to Sonde Data at South Broadway......................................................5-69 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS x February 2011 List of Figures (continued) No. Title Page 5-55 Comparison of Model to Sonde Data at Morgan Ford Road..................................................5-70 5-56 Comparison of Model to Sonde Data at Riverview Road.......................................................5-70 5-57 Comparison of Model to Sonde Data at Lewis and Clark Boulevard.....................................5-71 5-58 Comparison of Model to Sonde Data at Purdue Avenue during Dry Weather.......................5-71 5-59 Comparison of Model to Sonde Data at Purdue Avenue during Wet Weather Event............5-72 6-1 Assessment of Probability of the Year 2000 Backwater Event................................................6-2 6-2 Typical Year Average DO Compliance for Lower River Des Peres (Daily Average of 5 mg/L)..............................................................................................6-4 6-3 Typical Year Minimum DO Compliance for Lower River Des Peres......................................6-5 6-4 Typical Recreation Season Geometric Mean E. coli for Lower River Des Peres ....................6-6 6-5 Comparison of Peak Wet Weather and Dry Weather E. coli Concentration Profiles for the Lower River Des Peres....................................................................................6-6 6-6 Typical Year Average DO Compliance for Maline Creek (Daily Average of 5 mg/L)...........6-7 6-7 Typical Year Minimum DO Compliance for Maline Creek.....................................................6-8 6-8 Typical Recreation Season Geometric Mean E. coli for Maline Creek....................................6-8 6-9 Typical Year Average DO Compliance for Upper River Des Peres (Daily Average of 5 mg/L)............................................................................................6-10 6-10 Typical Year Minimum DO Compliance for Upper River Des Peres....................................6-10 6-11 Typical Recreation Season Geometric Mean E. coli for Upper River Des Peres...................6-11 6-12 Comparison of Peak Wet Weather and Dry Weather E. coli Concentration Profiles for the Upper River Des Peres...................................................................................6-12 7-1 Level 1 and Level 2 Screening Process....................................................................................7-1 7-2 Maline Creek CSOs ..................................................................................................................7-7 7-3 Gingras Creek CSO.................................................................................................................7-11 7-4 Mississippi River CSOs..........................................................................................................7-12 7-5 Upper River Des Peres CSOs .................................................................................................7-15 7-6 River Des Peres Tributaries CSOs..........................................................................................7-17 7-7 Lower and Middle River Des Peres CSOs..............................................................................7-19 8-1 Maline Creek CSOs - Integrated Control Alternatives.............................................................8-4 8-2 Maline Creek Cost-Performance - Alternative 1......................................................................8-6 8-3 Maline Creek Cost-Performance - Alternative 2......................................................................8-6 8-4 Maline Creek Total Present Worth Comparison.......................................................................8-7 8-5 Gingras Creek CSO - Integrated Control Alternatives.............................................................8-9 8-6 Gingras Creek Cost-Performance - Alternative 1...................................................................8-10 8-7 Gingras Creek Cost-Performance - Alternative 2...................................................................8-10 8-8 Gingras Creek Cost-Performance - Alternative 3...................................................................8-11 8-9 Gingras Creek Total Present Worth Comparison...................................................................8-11 8-10 Mississippi River CSOs - Integrated Control Alternatives.....................................................8-13 8-11 Mississippi River Cost-Performance ......................................................................................8-14 8-12 Upper River Des Peres CSOs - Integrated Control Alternatives............................................8-16 8-13 Upper River Des Peres Cost-Performance..............................................................................8-17 8-14 River Des Peres Tributaries CSOs - Integrated Control Alternatives.....................................8-19 8-15 River Des Peres Tributaries Cost-Performance - Alternative 1..............................................8-20 8-16 River Des Peres Tributaries Cost-Performance - Alternative 2..............................................8-20 8-17 River Des Peres Tributaries Total Present Worth Comparison..............................................8-21 8-18 Lower and Middle River Des Peres CSOs - Integrated Control Alternatives ........................8-23 8-19 Lower and Middle River Des Peres Cost-Performance - Alternative 1..................................8-25 8-20 Lower and Middle River Des Peres Cost-Performance - Alternative 2..................................8-25 Metropolitan St. Louis Sewer District CSO LTCP Update TABLE OF CONTENTS xi February 2011 List of Figures (continued) No. Title Page 8-21 Lower and Middle River Des Peres Cost-Performance - Alternative 3..................................8-26 8-22 Lower and Middle River Des Peres Total Present Worth Comparison..................................8-26 8-23 Comparison of Scenarios - System-Wide Benefits.................................................................8-33 8-24 Comparison of Scenarios - Urban Streams.............................................................................8-33 8-25 Control Scenario Cost-Performance Comparison...................................................................8-34 9-1 Stakeholder Interviews by Organizational Type.......................................................................9-2 9-2 Community Briefings/Presentations by Type...........................................................................9-6 9-3 Rate Increase Affordability - Pre-Survey ...............................................................................9-13 9-4 Rate Increase Affordability - Post-Survey..............................................................................9-13 9-5 Attendance & Survey Data.....................................................................................................9-15 10-1 Baseline CIRP - Projected Expenditures in Nominal Dollars ................................................10-8 10-2 Baseline Scenario: Projected Typical Residential Bills as Percent of MHI by Ratepayer Group.......................................................................................................10-8 11-1 Selected Long-Term Control Plan - Major Components........................................................11-3 11-2 Maline Creek CSO Control Components ...............................................................................11-5 11-3 Gingras Creek CSO Control Components..............................................................................11-6 11-4 Upper River Des Peres CSO Control Components.................................................................11-7 11-5 River Des Peres Tributaries CSO Control Components.........................................................11-8 11-6 Lower and Middle River Des Peres CSO Control Components...........................................11-10 11-7 Typical Year Minimum DO Compliance for Upper River Des Peres..................................11-21 11-8 Typical Year Minimum DO Compliance for Lower River Des Peres..................................11-22 11-9 Typical Year Minimum DO Compliance for Upper River Des Peres with Various Additional Controls.........................................................................................11-23 11-10 Typical Year Minimum DO Compliance for Lower River Des Peres with Various Additional Controls.........................................................................................11-23 11-11 LTCP Program Implementation Schedule............................................................................11-25 12-1 CSO Volume Reduction in the Harlem CSO Drainage Area.................................................12-5 This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-1 February 2011 EXECUTIVE SUMMARY Purpose The Metropolitan St. Louis Sewer District (MSD) provides wastewater and stormwater service to approximately 1.4 million people in a 535-square-mile service area encompassing the independent City of St. Louis and most of St. Louis County. The collection system owned and operated by MSD consists of over 9,600 miles of pipe, making it the fourth largest in the United States. Most of MSD’s customers are served by separate sanitary and storm sewers. However, approximately 75 square miles of St. Louis City and adjoining St. Louis County are served by a combined sewer system, as shown in Figure ES-1. During dry weather, the capacity of the combined sewer system is sufficient so that wastewater is conveyed to MSD’s wastewater treatment plants. During heavy rainfall, the combination of stormwater and wastewater may exceed the capacity of the combined sewer system. The excess flow, called combined sewer overflow (CSO), is discharged directly to the Mississippi River or to one of the river’s tributary streams through permitted outfall pipes. Figure ES-1 MSD’s Service Area and Combined Sewer Area Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-2 February 2011 The U.S. Environmental Protection Agency (EPA) issued a CSO Control Policy in 1994 intended to eventually bring CSOs nationwide into compliance with the Clean Water Act. The goals of CSO control are to: • Ensure that if CSOs occur, they are only as a result of wet weather, • Bring all wet weather CSO discharge points into compliance with the technology-based and water quality-based requirements of the Clean Water Act, and • Minimize the impacts of CSOs on water quality, aquatic biota, and human health. The policy requires agencies with CSOs to prepare a Long-Term Control Plan (LTCP) describing how they will accomplish these goals. MSD prepared and submitted its original LTCP to the Missouri Department of Natural Resources (MDNR) in 1999, but due to conflicts between Missouri law and the federal Clean Water Act, MDNR could not approve the submitted plan. A second, phased-implementation LTCP was prepared for MDNR in 2004 in accordance with State laws and regulations. This LTCP was approved by MDNR but was later disapproved by EPA. Following discussions aimed at resolving the conflicts, EPA and MDNR requested that MSD update its original LTCP. This report describes the development and selection of MSD’s updated plan for controlling combined sewer overflows. Certain controls from the 2004 phased-implementation LTCP have been incorporated into the current LTCP, along with additional control measures to meet the requirements of the Clean Water Act and CSO Control Policy. The 2004 phased-implementation LTCP is no longer considered to be in effect. CSO Locations and Impacted Waterways Within MSD’s combined sewer area there are a total of 199 CSO outfalls. These outfalls are included as permitted discharge locations in the Missouri State Operating Permits issued to MSD by MDNR. One permit covers the Bissell Point service area (MO-0025178) while the other covers the Lemay service area (MO-0025151). During wet weather, these CSOs may discharge to the following waterways: • Mississippi River (60 CSOs) • River Des Peres – Lower and Middle (52 CSOs) • River Des Peres – Upper (39 CSOs) • Tributaries to the River Des Peres (42 CSOs) • Maline Creek (4 CSOs) • Gingras Creek (1 CSO) • Gravois Creek (1 CSO, recently separated and removed) The locations of these waterways and CSOs are shown in Figure ES-2. Characteristics of these waterways, including applicable beneficial designated uses, are described below. None of these waterways have been identified as meeting the definition of Sensitive Areas contained in the CSO Control Policy. Sensitive Areas are those that should receive the highest priority for potential elimination or re-location of CSOs if feasible. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-3 February 2011 Figure ES-2 CSO and Receiving Water Locations Lower & Middle River Des Peres – The Lower River Des Peres starts at the confluence with Deer Creek and extends about six miles downstream to the Mississippi River. Flow consists of a small base flow, and large volumes of intermittent storm drainage from runoff, storm sewers, and combined sewers. The Lower River Des Peres is subject to backwater from the Mississippi River. This segment of the River Des Peres is classified for livestock & wildlife watering, warm water aquatic life protection, and secondary contact recreation1. The Middle River Des Peres extends approximately seven and one-half miles from the intersection of Dartmouth and Harvard Streets in University City to the confluence with Deer Creek. The upper four and one-half mile reach has been enclosed and is a combined sewer. The lower three mile reach, beginning near the Macklind Pump Station, is an open channel with a concrete base and concrete or rip- rap slopes. Flow is intermittent, consisting entirely of storm drainage from the Upper River Des Peres and combined sewers. The Middle River Des Peres is unclassified. 1 Designated uses are based on 10 CSR 20-7.031, Water Quality Standards, July 31, 2008, and revisions approved by Missouri Clean Water Commission on July 1, 2009. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-4 February 2011 Upper River Des Peres – The Upper River Des Peres extends approximately six miles in the Lemay service area from near Ashby and Warson Roads to the intersection of Dartmouth and Harvard Streets in University City. Flow is intermittent, and consists of storm drainage from separate storm sewers and overflows from combined sewers. The Upper River Des Peres is unclassified. Maline Creek – Maline Creek extends approximately seven miles from east of Lambert-St. Louis International Airport through the Bissell Point service area to the Mississippi River. Flow is intermittent, and consists mostly of storm runoff and drainage from storm sewers. The lower reaches of the creek are subject to backwater from the Mississippi River. One mile of the creek is classified for livestock & wildlife watering, warm water aquatic life protection, and recreational uses. The lower half-mile segment, which receives CSO discharges, is classified for secondary contact recreation. The upper half- mile segment, above the CSO locations, is classified for whole body contact recreation (Class B). Mississippi River – The Mississippi River at St. Louis receives significant point and nonpoint source loads from a 697,000 square mile drainage area encompassing all or part of 13 states, as well as local discharges from municipal, industrial, and agricultural wastewater treatment facilities located in St. Louis City and St. Louis County, Missouri, and Madison and St. Clair Counties, Illinois. The Mississippi River at St. Louis has a daily average flow of approximately 175,000 cubic feet per second. The segment of the river that receives CSO flows from MSD’s service area is classified for irrigation, livestock & wildlife watering, warm water aquatic life protection, drinking water supply, industrial process and cooling water supply, and secondary contact recreation. Two Use Attainability Analyses have been conducted to support the secondary contact recreation use designation. Assessment of Current CSO Impacts To assess the impact of CSOs on these waterways, MSD collected in-stream water quality data and developed hydraulic models of its combined sewer system. Computer models of the CSO-impacted portions of the River Des Peres and Maline Creek were also developed. In developing these models, it was also necessary to model the runoff from portions of these watersheds that are served by separate stormwater systems. These computer models were calibrated to flow, rainfall, and water quality data collected over a multi-year period. A review of existing water quality data was conducted to determine parameters that should be modeled to assess the impact of CSOs. This review concluded that, for the tributaries receiving CSOs, bacteria and dissolved oxygen are parameters of concern, and ammonia is a potential parameter of concern. For the Mississippi River, neither bacteria, dissolved oxygen nor ammonia are parameters of concern that require modeling to assess the impact of CSOs. Therefore, water quality data alone were used to assess impacts on the Mississippi River. CSO planning was based on typical or “average year” conditions, in accordance with EPA guidance. MSD selected the year 2000 rainfall as representative of system-wide average annual conditions, based on a detailed statistical analysis of 57 years of hourly rain data from Lambert-St. Louis International Airport. Year 2000 Mississippi River stage, which influences backwater conditions in the tributaries, was also deemed to be typical, based on a stage-exceedance analysis using 75 years of daily river data. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-5 February 2011 The hydraulic models of the combined sewer system allowed estimation of CSO overflow volumes and frequencies to the various waterways for the average year conditions, as summarized in Table ES-1. Waterway CSO Volume (billion gallons) Number of Overflow Events River Des Peres and tributaries 6.15 62 Maline Creek 0.15 29 Gingras Creek 0.02 33 Mississippi River 6.95 65 Total 13.3 Table ES-1 Estimated CSO Occurrence for Average Year (Year 2000) The estimated volumes were used to calculate pollutant loadings from the combined sewer system. Water quality in the River Des Peres and Maline Creek was modeled for the average year conditions using the calculated loadings from the CSOs, separate storm runoff, and upstream boundaries. Simulated water quality parameters included E. coli bacteria, carbonaceous biochemical oxygen demand (CBOD), nitrogen (organic and ammonia), and dissolved oxygen. The information below summarizes the results of the model simulations and conclusions from in-stream data. Lower & Middle River Des Peres – Model calculations demonstrate that ammonia criteria are met 100 percent of the time during a typical year. While exceedances of dissolved oxygen criteria occur regularly in the Lower River Des Peres, the model indicates that removal of CSOs does not greatly increase the time of compliance. Most dissolved oxygen exceedances occur during wet weather, but some occur during dry weather as well, primarily during periods when backwater from high water levels in the Mississippi River reduce flow velocities and reaeration in the River Des Peres channel. Other factors influencing dissolved oxygen levels include plant photosynthesis and respiration, stream temperatures, stormwater discharges, and sediment oxygen demand. Compliance with the secondary contact recreation criteria in the typical year is not an issue, and complete removal of CSOs has a relatively minor effect on reducing the geometric mean bacteria densities. Upper River Des Peres – Model calculations demonstrate that ammonia criteria are met 100 percent of the time during a typical year. Exceedances of dissolved oxygen criteria occur, partly as a result of photosynthesis-respiration, but also as a result of CSOs. Maline Creek – Modeling demonstrates that ammonia criteria are met 100 percent of the time during a typical year. Exceedances of dissolved oxygen criteria occur regularly; however, removal of CSOs has no perceptible impact due to their small volume relative to upstream and stormwater sources. Compliance with the secondary contact recreation criteria in the CSO-impacted segment is not an issue, and complete removal of CSOs again has a relatively minor effect on reducing the geometric mean bacteria densities. Mississippi River – Water quality data indicate that dissolved oxygen concentrations in the river are generally well above the 5 mg/L standard. Bacteria densities in the river are orders of magnitude less than bacteria in the other receiving streams and meet the secondary contact recreation standard. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-6 February 2011 Alternatives Evaluation MSD used a multi-level screening process, depicted in Figure ES-3, to develop and evaluate various alternatives to control CSOs to meet the goals of the CSO Control Policy and improve water quality in the impacted waterways. SOURCE CONTROL TECHNOLOGIES TREATMENT TECHNOLOGIES STORAGE TECHNOLOGIES COLLECTION SYSTEM CONTROLS LEVEL 1 SCREENING INTEGRATED CONTROL ALTERNATIVES SPECIFIC TO MSD’S SYSTEM AND RECEIVING WATERS LEVEL 2 SCREENING FEASIBLE AND COST-EFFECTIVE INTEGRATED CONTROL ALTERNATIVES 70+ TECHNOLOGIES 55 ALTERNATIVES 12 ALTERNATIVES LEVEL3 SCREENING 1 ALTERNATIVE SELECTED ALTERNATIVE FEASIBILITY COST- PERFORMANCE PUBLIC INPUT COST SOURCE CONTROL TECHNOLOGIES TREATMENT TECHNOLOGIES STORAGE TECHNOLOGIES COLLECTION SYSTEM CONTROLS LEVEL 1 SCREENING INTEGRATED CONTROL ALTERNATIVES SPECIFIC TO MSD’S SYSTEM AND RECEIVING WATERS LEVEL 2 SCREENING FEASIBLE AND COST-EFFECTIVE INTEGRATED CONTROL ALTERNATIVES 70+ TECHNOLOGIES 55 ALTERNATIVES 12 ALTERNATIVES LEVEL3 SCREENING 1 ALTERNATIVE SELECTED ALTERNATIVE FEASIBILITY COST- PERFORMANCE PUBLIC INPUT COST Figure ES-3 Alternatives Evaluation Process MSD began by evaluating a wide range of control technologies: • Source Control Technologies – those technologies that affect the quantity or quality of runoff prior to entering the collection system. • Collection System Controls – those technologies that affect CSO flows and loads once the runoff has entered the collection system. • Storage Technologies – those technologies that provide for storage of flows from the collection system for subsequent treatment after the storm is over and conveyance and treatment capacity have been restored. • Treatment Technologies – those technologies that provide for either local (at the CSO) or centralized treatment of CSO flows to reduce the pollutant loading to receiving waters. More than 70 CSO control technologies were evaluated (Level 1 Screening). Each technology was screened to determine its feasibility and applicability to the unique characteristics of MSD’s combined sewer system. Feasible CSO control technologies were then assembled into 55 Integrated Control Alternatives specific to each receiving water. Each Integrated Control Alternative consists of one or more of the following components: • Source Control Technologies that were determined to be applicable to all alternatives. • Collection System Technologies that were determined to be applicable to all alternatives. • Long-term CSO controls that have already been implemented by MSD or are currently being implemented by MSD that will continue to serve an important long-term role in controlling CSOs. These controls represent an investment of $0.6 billion that has already reduced annual CSO volumes by 38 percent. • New long-term CSO controls necessary to meet the established CSO control goals. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-7 February 2011 Each of the 55 Integrated Control Alternatives was then evaluated and screened to develop a short list of the most feasible and cost effective alternatives for further analysis (Level 2 Screening). Evaluation criteria included affordability, CSO flow/load reduction, constructability, expandability, operability, public acceptability, reuse of existing facilities, and infrastructure rehabilitation / upgrade opportunities. Twelve Integrated Control Alternatives remained after the Level 2 screening process. For each of these twelve alternatives, MSD: • evaluated a range of sizes of the 12 Integrated Control Alternatives that would achieve 0, an average of 1 to 3, an average of 4 to 7, and an average of 8 to 12 overflow events per year; • analyzed the impact that each of the 12 Integrated Control Alternatives is estimated to have on peak instantaneous and sustained flows to the Lemay and Bissell Point Treatment Plants; • estimated project costs, including capital costs, annual operation and maintenance costs, and total present worth (life-cycle) costs; • estimated the benefits arising from implementation; • conducted cost-performance (“knee of the curve”) analyses comparing estimated costs to the estimated benefits; and • involved its Stakeholder Advisory Committee and the public in reviewing the analysis results. This Level 3 screening process resulted in the identification of five CSO control scenarios that consist of combinations of the 12 Integrated Control Alternatives: • Scenario 1 – Complete elimination of CSOs • Scenario 2 – CSO control to the “knee-of-the-curve” on all CSOs • Scenario 3 – CSO control to the “knee-of-the-curve” on CSOs discharging to urban streams (e.g., Maline Creek, the River Des Peres and its tributaries), plus an enhanced green infrastructure program in areas with CSOs directly tributary to the Mississippi River • Scenario 4 – CSO control to a uniform minimum level of control (18 overflows per year) on all CSOs • Scenario 5 – CSOs to urban streams to receive a graduated level of control (higher control on smaller streams), plus an enhanced green infrastructure program in areas with CSOs directly tributary to the Mississippi River These scenarios were discussed with MSD’s Stakeholder Advisory Committee that was created for the LTCP public participation program, and the general public. Scenario 3 was selected to form the basis of the CSO control measures for the LTCP. The selection was based on a number of factors including: • Public and political acceptance of the proposed solutions, • Total program cost and resulting user rates, • Costs and benefits of existing controls, • Costs versus benefits, • Cascading effect of implementing controls, • Water quality gains, • Treatment plant impacts, and • Technical feasibility. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-8 February 2011 Figure ES-4 depicts the calculated annual system-wide overflow volume with each control scenario compared to the pre-control and current conditions. Figure ES-5 provides the same information for the urban streams only. Scenario 1 (complete sewer separation) is neither realistic nor affordable. Scenario 2 (uniform control everywhere) is significantly more expensive than Scenarios 3 and 5, and provides little added water quality benefit. Control Scenario 3 provides the maximum benefit on the urban streams, and the same system-wide benefit as Scenarios 4 and 5, at an affordable cost. 0 5 10 15 20 25 Pre-Control Modeled Conditions Scenario 5 Scenario 3 Scenario 4 Scenario 2 Scenario 1Annual CSO Volume (billion gallons) Figure ES-4 Comparison of Scenarios – System-Wide Benefits 0 1 2 3 4 5 6 7 8 9 Pre-Control Modeled Conditions Scenario 4 Scenario 5 Scenario 3 Scenario 2 Scenario 1Annual CSO Volume (billion gallons) Figure ES-5 Comparison of Scenarios – Urban Streams Scenario 1 Complete elimination Scenario 2 “Knee-of-the-curve” everywhere Scenario 3 “Knee-of-the-curve” on urban streams + enhanced green program on Mississippi Scenario 4 Uniform minimum Level of Control Scenario 5 Graduated control on urban streams + enhanced green program on Mississippi Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-9 February 2011 Public Involvement MSD conducted a focused public involvement program to engage the affected public in the above- described decision making process to select the long-term CSO controls. The program included the following components: • Face-to-face interviews with key stakeholders representing business, community, environmental, municipal, public health and regional planning organizations. These interviews were used to modify the public involvement program plan to make it more responsive to the public’s interests and external realities. • A Stakeholder Advisory Committee (SAC) comprising 12 municipal, environmental, regional, business and community representatives. The SAC reviewed program data and technical findings; increased community awareness of and support for the CSO control program; advanced MSD’s understanding of their constituents’ concerns, issues, priorities and interests; and served as a sounding board and connection to the community at-large. • Stakeholder and community presentations to a wide variety of business, community, environmental, legislative, municipal and professional groups. The presentations were educational in nature, intended to raise awareness of the CSO control program. • Public open houses at 13 locations throughout MSD’s service area. The open houses were designed to educate the public about CSOs and their impacts, review options for controlling CSOs, identify the public’s preferred options and explore opportunities for additional action by MSD and the public in addressing the CSO issue. These public deliberation sessions allowed 451 members of the public to directly weigh in on the selection of CSO controls. • A Clean Rivers Healthy Communities web site that provided the public with opportunities to learn more about the program, participate virtually in the public open houses, and leave feedback for the CSO control program. • Outreach to the media, through such activities as tours and briefings, to aid their understanding of complex issues as they communicated with their audiences. • Telephone surveys to gauge public understanding of the CSO issue. The input received from the public during these activities was used by MSD to help define the CSO control scenarios that were considered during the alternatives evaluation process, and to assist in selection of the preferred control option. Follow-up public open houses were conducted to present and discuss the selected control option with the community. MSD intends to continue its public involvement program throughout the LTCP approval and implementation process. Selected Plan Details MSD is committed to continue to improve water quality in the Mississippi River, Maline Creek, and the River Des Peres and its tributaries. The selected LTCP controls build upon MSD’s previous investments in CSO control and provide for significant additional reductions in CSO volumes and pollutant loadings. The selected controls will also allow MSD the financial capability to maintain its existing infrastructure and tackle significant issues in its separate sewer systems. The selected LTCP consists of controlling CSOs to MSD’s urban streams to the point where further expenditures yield significantly diminished returns (the “knee-of-the-curve”), coupled with an enhanced green infrastructure program in areas with CSOs that discharge directly to the Mississippi River. Source controls and collection system controls common to all areas are also part of the selected plan, as are the CSO controls that MSD has already implemented during the planning period. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-10 February 2011 The selected LTCP components are listed in Table ES-2 along with estimated total capital and total present worth costs. Costs for long-term CSO controls that have already been implemented by MSD, or are currently being implemented, are not included in the table. The estimated total capital cost of these completed and ongoing improvements is $634 million. Figure ES-6 depicts the locations of the principal new components. Cost Opinions ($million)1 LTCP Component Capital Cost Total Present Worth System-wide Source Control Technologies Note 2 Note 2 Collection System Technologies Note 2 Note 2 Maline Creek Bissell Point Overflow Regulation System Note 2 Note 2 Sewer Separation of Outfalls 053 and 060 Note 2 Note 2 Treatment unit to treat overflows from Outfall 051 and storage tank to store overflows from Outfall 052 31 41 Gingras Creek Separation of three storm sewers from combined sewer system and relocation of Outfall 059 6.0 6.1 Upper River Des Peres Skinker-McCausland Tunnel to express convey separate sewer system flows around the combined sewer system Note 2 Note 2 Storage tunnel to store flows from CSO outfalls to the Upper River Des Peres 183 212 River Des Peres Tributaries Sewer separation of 15 smaller CSOs Note 2 Note 2 Elimination of all CSO outfalls to tributaries, tunnel to store/convey flows to the River Des Peres channel 396 434 Lower and Middle River Des Peres Lemay Overflow Regulation System Note 2 Note 2 Skinker-McCausland Tunnel to express convey separate sewer system flows around the combined sewer system Note 2 Note 2 Full utilization of excess primary treatment capacity at Lemay Treatment Plant Note 2 Note 2 Sewer separation of 5 smaller CSOs Note 2 Note 2 Repair of inflow to interceptor sewers under River Des Peres Note 2 Note 2 Upstream CSO controls (Upper River Des Peres) Note 3 Note 3 Flow storage in 29-ft horseshoe sewers under Forest Park and in new storage tunnel, 100 MGD treatment unit near Outfall 063, removal of secondary treatment bottlenecks at WWTP 1,103 1,208 Mississippi River Bissell Point Overflow Regulation System Note 2 Note 2 Separation of two major industrial sources Note 2 Note 2 Full utilization of excess primary treatment capacity, and maximizing flow pumped to the Bissell Point Treatment Plant Note 2 Note 2 Sewer separation for Outfall 055 Note 2 Note 2 Upstream CSO controls (Maline Creek, River Des Peres) Note 3 Note 3 Enhanced green infrastructure program 100 100 Grand Total 1,819 2,001 Notes: 1. Costs updated to ENR Construction Cost Index of 8580. 2. Costs for controls already implemented or currently being implemented are not included as LTCP future costs. 3. Costs for upstream CSO controls are reflected under the appropriate upstream components. Table ES-2 Selected Long-Term Control Plan Components Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-11 February 2011 Figure ES-6 Selected Long-Term Control Plan - Major Future Components The principal components of the control plan are described below. System-wide Controls – System-wide source controls include green infrastructure, illicit connection control, stormwater detention for new developments, catch basin cleaning, solids/floatables control, illegal dumping control, hazardous waste collection, good housekeeping, street sweeping, construction erosion and waste control, litter control, industrial pretreatment program, stream teams, community clean-up programs, recycling programs, pet waste management, proper yard waste disposal, and the installation and maintenance of warning signage. System-wide collection system controls include diversion structure maintenance, outfall maintenance, sewer system cleaning and sewer separation for new developments or redevelopments. Maline Creek CSO Controls – The CSO controls selected for Maline Creek are estimated to control overflows to a level of 4 overflows per year in the typical year. The controls include the following components: • The existing Bissell Point Overflow Regulation System will continue to be operated to control the influence of Mississippi River stage on the capture of flows at Bissell Point Outfall 051 to Maline Creek. • Infiltration and inflow (I/I) controls will be implemented in the separate sewer systems upstream of the Maline Drop Shaft as part of MSD’s efforts to eliminate constructed SSOs. Reduced peak flows Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-12 February 2011 resulting from I/I control may allow for greater capture of wet weather flows from the combined sewer system. • Bissell Point Outfalls 053 and 060 will be eliminated by sewer separation. • A 1.0 million gallon storage facility will be constructed to control overflows from Bissell Point Outfall 052. Control features will include modifications to the existing drop shaft/diversion structure, flow screening facilities, an above- or below-grade storage tank, a tank dewatering pump station, and interconnecting piping. Combined sewage will be temporarily stored at the facility during a storm event until the north leg of the Bissell Point Interceptor Tunnel has capacity to convey the return flow to the Bissell Point Treatment Plant for secondary treatment. • A 94 MGD treatment facility will be built to treat CSO flows from Bissell Point Outfall 051 prior to discharge to Maline Creek. Control features will include a modified diversion structure, pump station to the treatment facility, and Enhanced High Rate Clarification treatment unit(s) providing screening, the equivalent of primary treatment and disinfection to the design flows prior to discharge to Maline Creek. Gingras Creek CSO Controls – The CSO controls selected for Gingras Creek will eliminate the occurrence of CSOs. The controls include the following components: • Three large storm sewers will be disconnected from the existing combined sewer system and connected to a new separate storm sewer discharging to Gingras Creek. • Bissell Point Outfall 059 will be eliminated. The existing 66-inch combined sewer will be extended to the Baden combined sewer system (Gingras Creek Branch of the Baden Trunk Sewer). Upper River Des Peres CSO Controls – The CSO controls selected for the Upper River Des Peres are estimated to control overflows to a level of 4 overflows per year in the typical year. The controls include the following components: • MSD will continue to operate and maintain the Skinker-McCausland Tunnel to express route separate sanitary flows around the combined portions of the Upper River Des Peres sewer system, thereby eliminating the overflow of this separate sanitary flow from the combined sewer system during wet weather. • A 30 million gallon deep storage tunnel will be constructed to store flows from the 39 CSO outfalls to the Upper River Des Peres. The tunnel is estimated to be approximately 24 feet in diameter, extending approximately 9,000 feet from near Lemay Outfall 090 to a location near Outfall 064. The existing 39 CSO outfalls will be consolidated to approximately 4 or 5 drop shaft locations along the tunnel. A tunnel dewatering pump station will pump stored flow back to the Skinker-McCausland Tunnel and Lemay Treatment Plant for secondary treatment as capacity becomes available. River Des Peres Tributaries CSO Controls – The CSO controls selected for the River Des Peres tributaries (Deer, Black, Hampton and Claytonia Creeks) are estimated to control overflows to a level of 4 overflows per year in the typical year. The controls include the following components: • Fifteen small CSO outfalls will be eliminated by sewer separation. • A tunnel, approximately 20 feet in diameter and 12,000 feet long, will convey all flows from the remaining CSOs to a single location on the River Des Peres main channel in the vicinity of its confluence with Deer Creek. Consequently, the CSO outfalls along the tributaries, remaining after the above-mentioned sewer separations are completed, will be eliminated. The tunnel size necessary for total flow conveyance is adequate to provide CSO flow storage to the desired level of control. The tunnel alignment will generally follow the creek alignment from the confluence of Claytonia and Hampton Creeks to the River Des Peres main channel. Approximately five or six drop shafts are Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-13 February 2011 anticipated to direct flow from shallow conveyance piping to the deep tunnel. A dewatering pump station at the tunnel’s downstream end will pump stored flow from the tunnel to the Lemay Treatment Plant, where it will receive full secondary treatment, as conveyance and treatment capacity becomes available. Lower & Middle River Des Peres CSO Controls – The CSO controls selected for Lower and Middle River Des Peres are estimated to control overflows to a level of 4 overflows per year in the typical year. The controls include the following components: • The existing Lemay Overflow Regulation System will continue to be operated to control the influence of Mississippi River stage on the capture of flows at outfalls along the Lower and Middle River Des Peres. • MSD will continue to operate and maintain the Skinker-McCausland Tunnel to express route separate sanitary flows around the combined portions of the Upper River Des Peres sewer system, thereby eliminating the overflow of this separate sanitary flow from Lemay Outfall 063 during wet weather. • MSD will utilize excess primary treatment capacity at the Lemay Treatment Plant to maximize treatment during wet weather. Upon completion of influent pumping and ongoing plant outfall modifications, the expanded treatment plant will have the ability to treat 340 MGD through its preliminary and primary treatment facilities. Flow rates of up to 340 MGD will be pumped and treated during wet weather events. The current capacity of the secondary treatment facilities is 167 MGD. • Five small CSO outfalls will be eliminated by sewer separation. • MSD will correct the excessive inflow problem to the interceptor sewers beneath the Lower River Des Peres channel that has been hampering MSD’s ability to maximize the capture of wet weather flows from its combined sewer system. These excessive inflows occur during periods of backwater due to high Mississippi River stage. • CSO controls implemented on the Upper River Des Peres and River Des Peres tributaries will benefit the Lower and Middle River Des Peres by reducing overflow volumes and pollutant loadings. • The existing dual 29-foot wide horseshoe sewers beneath Forest Park (immediately upstream of Lemay Outfall 063) will be utilized to store up to 25 million gallons of wet weather flow. This will be accomplished by the construction of a flow control gate at Outfall 063. • A 100 MGD Enhanced High Rate Clarification treatment unit will be constructed adjacent to Outfall 063 to provide for the equivalent of primary treatment and disinfection of up to 100 MGD of flow from Outfall 063. Treated flow will be discharged to the Middle River Des Peres channel. • A 206 million gallon deep storage tunnel will be constructed to store flows from the CSO outfalls to the Lower and Middle River Des Peres. The tunnel is estimated to be approximately 28 feet in diameter, extending approximately 47,400 feet from Outfall 063 to a location near the Lemay Treatment Plant. The existing CSO outfalls will be consolidated to approximately 14 drop shaft locations along the tunnel. A tunnel dewatering pump station will pump stored flow directly to the Lemay Treatment Plant for secondary treatment as capacity becomes available. • Flow capacity bottlenecks that currently limit secondary treatment capacity at the Lemay Treatment Plant to 167 MGD will be removed. It is anticipated that secondary capacity can be increased to 210 MGD. Stress testing will be performed to determine maximum treatable flow rates for the plant. Mississippi River CSO Controls – The CSO controls described above for the receiving waters that are tributary to the Mississippi River will complement the significant long-term controls already implemented on the Mississippi River outfalls. These controls, along with the enhanced green Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-14 February 2011 infrastructure program proposed by MSD, will provide meaningful reductions in overall CSO volumes and pollutant loadings to the Mississippi River. • The existing Bissell Point and Lemay Overflow Regulation Systems will continue to be operated to control the influence of Mississippi River stage on the capture of flows at the CSO outfalls to the Mississippi River. • Two significant industrial users currently have their wastewater discharges disconnected from the combined sewer system and connected directly to the Bissell Point Interceptor Tunnel. • MSD will utilize excess primary treatment capacity at the Bissell Point Treatment Plant to maximize treatment during wet weather. The treatment plant has the ability to treat 350 MGD through its preliminary and primary treatment facilities. Flow rates of up to 350 MGD will be pumped and treated during wet weather events, except during extremely high river stage conditions, when the capacity of the effluent pump station limits total plant flow to approximately 250 MGD. The current capacity of the secondary treatment facilities is 250 MGD. • Bissell Point Outfall 055 will be eliminated by sewer separation. • In addition to the above-noted CSO long-term controls that have already been implemented, the CSO controls implemented along Maline Creek, and the River Des Peres and its tributaries will benefit the Mississippi River by significantly reducing CSO volumes and pollutant loadings. • MSD will invest $100 million in an enhanced green infrastructure program focused on its combined sewer areas with CSOs that are directly tributary to the Mississippi River. The overall objective is to identify and implement projects and programs that will significantly reduce CSOs and provide additional environmental benefit. A program goal is to reduce CSO overflow volumes to the Mississippi River by 10 percent. This goal will be updated based upon the results of initial projects comprising the pilot phase of the program. MSD has limited direct control over the infrastructure and policies that impact the magnitude of storm runoff in the combined sewer areas. To address this challenge, MSD plans to work with local units of government, private developers, and other stakeholders to implement the program. It is anticipated that MSD’s enhanced green infrastructure program will comprise the following types of activities: – Community outreach and education programs. – Partnering with the Land Reutilization Authority and the St. Louis Development Corporation to implement green infrastructure on to-be-developed properties in some of the most economically- distressed portions of the City of St. Louis. Once the pilot program is complete, perform similar work with like entities in the economically-distressed portions of North St. Louis County located within the Bissell Point service area. – Lot-scale and neighborhood-scale stormwater management projects that incorporate green infrastructure. – Working with developers to encourage green infrastructure implementation in specific redevelopment opportunities. – Support of rain barrel and rain garden implementation programs. LTCP Benefits and Water Quality Standards Review and Revision The selected CSO controls are intended to bring CSOs into compliance with technology-based and water quality-based requirements of the Clean Water Act and to minimize the impact of CSOs on water quality, aquatic biota and human health. Implementation of the selected LTCP will substantially reduce the occurrence and magnitude of CSOs to MSD’s urban streams as well as significantly reduce CSO volumes and loadings to the Mississippi River. For the parameters of concern – ammonia, bacteria and dissolved oxygen – water quality data and water quality simulations indicate that, with the LTCP controls implemented: Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-15 February 2011 • Ammonia criteria, acute and chronic, are met for all receiving waters. • Geometric mean criteria for E. coli bacteria are met for all receiving waters. • The dissolved oxygen criteria are met in the Mississippi River. • Exceedances of water quality criteria for dissolved oxygen are predicted to occur in Maline Creek. CSOs, however, play a very small role, as their volume is very small compared to upstream and storm flows. • Exceedances of water quality criteria for dissolved oxygen are predicted to occur in the River Des Peres, partially due to CSOs. Despite the significant reductions in pollutant loadings associated with the selected LTCP controls, these controls are expected to only slightly improve the percent compliance with dissolved oxygen criteria in the urban streams (Maline Creek and the River Des Peres). Even complete elimination of CSO and stormwater discharges would not significantly improve dissolved oxygen conditions. Other contributing factors to the problem include diurnal swings in dissolved oxygen due to plant photosynthesis-respiration, and backwater conditions caused by high Mississippi River stage. Because of these factors, a site-specific dissolved oxygen criterion for the River Des Peres and Maline Creek will be necessary. Preparation of the Use Attainability Analysis necessary to determine the highest attainable use should not delay agreement on the selected CSO controls because it is clear that even elimination of the CSOs would not address the stream impairments. Financial Impacts and Schedule MSD has evaluated the financial impacts of constructing and operating the improvements contemplated in its total Capital Improvement and Replacement Program (CIRP). The CIRP comprises not only the CSO controls described in this LTCP, but also the need to operate and maintain current assets, control wet weather flows in sanitary sewer systems, construct wastewater treatment plant improvements, and provide stormwater services. MSD’s financial analysis is consistent with the principles of EPA’s Guidance on Financial Capability Assessment and Schedule Development. The assessment is based on determining the amount of net revenues that may be generated under feasible rate and fee increase scenarios. The feasibility of these scenarios is based in part on current and projected burden of wastewater and stormwater service costs, and in part on the unique socio-economic attributes of MSD’s service area. MSD has employed its cash flow forecasting model to determine the capital project financing capacity under a range of wastewater and stormwater rate slope scenarios and alternative configurations of the CIRP. The analyses were based on well documented information on the District’s financial position, and several critical assumptions such as inflation rates, median household income (MHI) growth rate, and capital financing (bond) parameters. The resulting cash-flow projections have allowed MSD to determine the amount and pace of CIRP spending that can be financed within the District’s capabilities. MSD’s proposed 23-year baseline schedule for implementing CSO controls, together with other CIRP expenditures, represents an unprecedented capital investment for MSD’s service area that will require substantial rate increases. These rate increases build the necessary revenue generation capacity for MSD to aggressively control CSOs and address other water quality issues (SSO control, wastewater treatment, and stormwater management). At the same time, these increases will elevate claims on ratepayer income already strained by recent economic decline, as shown in Figure ES-7. Metropolitan St. Louis Sewer District CSO LTCP Update EXECUTIVE SUMMARY Page ES-16 February 2011 0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 2010 2015 2020 2025 2030 2035 2040Residential Bill as % of MHISt. Louis County Combined (Weighted Avg) St. Louis City Low Income EPA High Burden Threshold Figure ES-7 Projected Typical Residential Bills for Proposed Capital Improvement and Replacement Program The projected rate increases place portions of the MSD ratepayer population at the threshold of “High Burden” while imposing potentially problematic burdens on low-income ratepayers throughout the District’s service area. MSD’s approach to financial capability assessment also contemplates mechanisms to assess and manage risk should significant adverse changes to its financial circumstances or other financial or budgetary issues arise. MSD will periodically update projected cash flows and estimated project costs. In the event that the funding level is significantly less than anticipated, or project costs are significantly higher than anticipated, MSD may propose adjustments to project scopes and/or timelines consistent with available funding levels and project costs. Post-Construction Compliance Monitoring Post-construction compliance monitoring will be performed to determine the effectiveness of the LTCP in meeting the plan’s performance objectives, and to assess and document impacts on receiving waters resulting from implementation of the CSO control measures. Documentation of the monitoring results will be provided in annual progress reports that will summarize: • Final design criteria and sizing of the CSO control program elements, • CSO control measure performance (e.g., CSO activation and flow data), • Rainfall data, • Receiving water quality data, • Progress in updating and calibrating/validating the hydraulic models, • Status in achieving performance objectives based on continuous simulation modeling for the typical year, • Identification of variances from expected results, and • Proposed corrective action of LTCP program element(s), if needed. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-1 February 2011 1. INTRODUCTION 1.1 Overview and Purpose The Metropolitan St. Louis Sewer District (MSD or District) provides wastewater and stormwater service to approximately 1.4 million people in a 535-square-mile service area encompassing the independent City of St. Louis and most of St. Louis County. The collection system owned and operated by MSD consists of over 9,600 miles of pipe, making it the fourth largest in the United States. Most of MSD’s customers are served by separate sanitary and storm sewers. However, approximately 75 square miles of St. Louis City and adjoining St. Louis County are served by a combined sewer system containing approximately 1,900 miles of sewer. MSD’s total area is divided into five major service areas: Bissell Point, Coldwater Creek, Lemay, Lower Meramec, and Missouri River. The combined sewer area is located within the Bissell Point and Lemay service areas, as shown in Figure 1-1. Figure 1-1 MSD’s Combined Sewer Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-2 February 2011 During dry weather, wastewater is collected in the combined sewer system and conveyed for treatment to either the Bissell Point Treatment Plant or the Lemay Treatment Plant. During light rainfall, a combination of stormwater and wastewater is similarly conveyed to the plants for treatment. But during heavy rainfall, the combination of stormwater and wastewater may exceed the capacity of the combined sewers or treatment plant. When these conditions occur, the excess flow, called combined sewer overflow (CSO), is discharged directly to the Mississippi River or to one of the river’s tributary streams. If the CSOs were not allowed to occur, the area’s streets, homes and businesses would be flooded. Figure 1-2 visually depicts how the combined sewer system operates during dry and wet weather. Figure 1-2 Combined Sewer System Operation During Dry and Wet Weather Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-3 February 2011 Within the area served by the Bissell Point Treatment Plant, there are 55 locations (outfalls) in the combined sewer system where overflows may occur during some wet weather events. In the area served by the Lemay Treatment Plant, there are 144 outfall locations. All 199 of these outfalls are listed in the current Missouri State Operating Permits for the two plants. These permits are issued and administered by the Missouri Department of Natural Resources. MSD is authorized by these permits to discharge from the 199 outfalls. Figure 1-3 indicates the permitted outfall locations. Figure 1-3 MSD’s Permitted Combined Sewer Overflow Outfalls Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-4 February 2011 Figure 1-5 Channelized River Des Peres The operating permits require MSD to update its Long-Term Control Plan (LTCP) originally submitted in 1999. The update presented in this report is the result of a multi-year planning effort by MSD staff and its team of consultants. The resulting plan is the cornerstone of MSD’s “Clean Rivers Healthy Communities Program.” 1.2 National Perspective MSD is not alone in its efforts to control sewer overflows and reduce their impact on the environment. Many communities across the United States, particularly in the Midwest, northeast and northwest, are also working to address this problem. EPA’s Report to Congress: Impacts and Control of CSOs and SSOs (US EPA, 2004) identified 746 communities in 32 states, including the District of Columbia, with combined sewer systems (see Figure 1-4). These communities reported a total of 9,348 CSO outfalls regulated under 828 operating permits. 1.3 Historical Background of MSD’s Combined Sewer System Prior to 1850 all sewage and storm runoff in the City of St. Louis drained to the Mississippi River, local creeks, or sink holes. Discussions about building sewers began in the early 1840s because many of the sink holes had been transformed into “slough ponds” as the underground drainage way became blocked. A new charter in 1843 gave the city authority to construct sewers. But efforts were sidetracked when the courts ruled that the city council had no power to sell bonds or levy sewer taxes. Finally, in March 1849, just prior to a major cholera outbreak in the city, state legislation was passed allowing the city to levy taxes for the construction of public sewers to relieve the growing nuisance. Thus, St. Louis became one of the first cities in the United States or Europe to construct public sewers to convey its sewage. Construction of the first sewer in St. Louis, the Biddle Street sewer on the north side of the city, began in the summer of 1849. By the early 1880s, over 200 miles of combined sewers had been built to drain much of the urbanized portions of the city. As the city expanded, sewer construction continued. By 1920, more than 870 miles of combined sewers drained sewage and stormwater away from the city into the Mississippi River or its tributaries. An interceptor sewer was built beneath the River Des Peres to convey sewage directly to the Mississippi River, keeping sewage out of the River Des Peres during dry weather. The river above the interceptor sewer was channelized and reinforced with rip rap to convey stormwater and combined sewage through the River Des Peres to the Mississippi River (see Figure 1-5). Sewerage of the older adjacent portions of St. Louis County continued in the tradition established in the city – combined sewers. No treatment of the sewage or stormwater was provided, the governmental authorities relying on the dilution afforded by the Mississippi River for purification. Figure 1-4 Location of Communities with Combined Sewer Overflows Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-5 February 2011 Substantial growth in the St. Louis area during the 1930s and 1940s led to increasing problems with sewage disposal, particularly in St. Louis County. In many areas, local sewers were allowed to empty into nearby ditches or streams. In other areas, localized treatment of wastewater was provided for, but was often inadequate to protect the environment and public health. The citizens and municipal officials soon recognized the need for a coordinated regional effort to provide proper wastewater collection and treatment. At a special election on February 9, 1954, the voters of the city and county approved a plan to create the Metropolitan St. Louis Sewer District as a separate governmental agency. The new agency was charged with the responsibility for wastewater collection and treatment, and stormwater management within its boundaries. MSD’s initial efforts focused on getting sewage out of local ditches, streams and rivers by constructing a system of interceptor sewers. Once this effort was underway, work began on providing treatment to the collected wastewater. Within the Bissell Point combined sewer area, an interceptor tunnel was built paralleling the Mississippi River. This tunnel conveyed wastewater to a new primary treatment facility that was constructed and went on line in 1970. Two-stage secondary treatment was added at the Bissell Point Treatment Plant in 1992 and 1993. Within the Lemay combined sewer area, a second interceptor sewer was built beneath the River Des Peres to collect wastewater. Primary treatment at the Lemay Treatment Plant went on line in 1968, followed by secondary treatment in 1985. Efforts to specifically address combined sewer overflows were initiated in the 1980s. A project known as the “Bissell Point Overflow Regulation System” was constructed between 1988 and 1998, substantially reducing the volume of overflows from the combined sewer system. A similar project, the “Lemay Overflow Regulation System” was built beginning in 1995. Other projects have separated some small combined sewer areas and provided for increased wet weather flow treatment at the two treatment plants. These efforts are described further in Section 3 of this report. Figure 1-6 highlights the progress made since the formation of MSD in reducing discharges from the combined sewer system. Figure 1-6 MSD’s Progress in Reducing CSO Volume 1954 to 2009 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 1. INTRODUCTION Page 1-6 February 2011 Even with MSD’s substantial efforts to provide interception and treatment of flows within its combined sewer system, the legacy portion of its collection system, dating from the 1850s to the early 20th century, still overflows to the Mississippi River and its tributaries during some wet weather events. Efforts to further control these combined sewer overflows are the subject of this planning document. 1.4 Long-Term Control Plan – Planning Approach EPA’s CSO Control Policy (US EPA, 1994) requires permit holders with combined sewer overflows to develop a long-term plan for controlling their CSOs. The policy became law with the passage of the Wet Weather Water Quality Act of 2000. The elements of the long-term CSO control plan, as defined in the CSO Control Policy, are listed below: • Characterization, Monitoring and Modeling of the Combined Sewer System • Public Participation • Consideration of Sensitive Areas • Evaluation of Alternatives • Cost/Performance Consideration • Operational Plan • Maximizing Treatment at the Existing POTW Treatment Plant • Implementation Schedule and Financial Capability Analysis • Post-Construction Compliance Monitoring Program Subsequent sections of this Long-Term Control Plan discuss each of the above-listed elements in depth. The CSO Control Policy also expects that the development of the long-term plan should be coordinated with the review and appropriate revision of water quality standards and implementation procedures to ensure that the long-term controls will be sufficient to meet water quality standards. MSD began updating its original (1999) Long-Term CSO Control Plan in 2002. Additional system characterization data were collected, hydraulic and water quality models were enhanced, and a detailed evaluation of alternatives was conducted, considering extensive and still on-going changes to Missouri’s water quality standards. Throughout this process, a substantial public engagement process was conducted. This LTCP report takes into consideration the public input received during that process, as well as regulatory agency input. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 2. REGULATORY BACKGROUND Page 2-1 February 2011 2. REGULATORY BACKGROUND 2.1 General CSOs are point source discharges to waters of the United States and are therefore subject to regulation under the Clean Water Act: • Section 301(a) prohibits the discharge of pollutants not in compliance with the Act; • Section 301(b) requires compliance with both technology-based and water quality-based effluent limitations; • Section 402(a) allows the issuance of National Pollutant Discharge Elimination System (NPDES) permits that allow pollutant discharges that meet the requirements of the Act; and, • Section 402(b) allows the States to administer the NPDES permit program. Implementation of the NPDES permit program is regulated under Title 40, Chapter I, Subchapter D of the Code of Federal Regulations. The U.S. Environmental Protection Agency (EPA) has delegated responsibility for clean water programs to the State of Missouri. Missouri’s Clean Water Law and its implementing regulations contain language similar to the Clean Water Act relative to point source discharges to waters of the State. 2.2 CSO Control Strategy On August 10, 1989, EPA issued its National Combined Sewer Overflow (CSO) Control Strategy (54 Federal Register 37370) with three objectives: • To ensure that if CSOs occur, they are only as a result of wet weather; • To bring all wet weather CSO discharge points into compliance with the technology-based and water quality-based requirements of the Clean Water Act (CWA); and • To minimize the impact of CSOs on water quality, aquatic biota, and human health. The National CSO Control Strategy also charged the States with developing statewide permitting strategies designed to reduce, eliminate, or control CSOs. Missouri’s CSO Strategy, which mirrored the federal strategy, was approved by EPA on July 13, 1990. On July 24, 1991, the Missouri Department of Natural Resources (MDNR) notified MSD that MSD would need to develop a plan to meet the objectives of the State’s CSO Strategy. In response, MSD initiated CSO management planning projects in its two service areas containing combined sewers in 1991 and 1992. 2.3 CSO Control Policy EPA began developing its CSO Control Policy in mid-1991 to elaborate on the CSO Control Strategy and to expedite compliance with the Clean Water Act. The final policy (59 Federal Register 18688) was signed by the U.S. EPA Administrator on April 11, 1994. The Clean Water Act was amended in 2000 to require that all NPDES permits issued after December 21, 2000 conform to the CSO Control Policy [33 U.S.C. §1342(q)(1)]. The CSO Control Policy represents a comprehensive national strategy to ensure that municipalities, permitting authorities, water quality standards authorities and the public engage in a comprehensive and coordinated planning effort to achieve cost effective CSO controls that ultimately meet appropriate health and environmental objectives. The Policy recognizes the site-specific nature of CSOs and their impacts and provides the necessary flexibility to tailor controls to local situations, including the development of phased long-term control plans. Major elements of the Policy ensure that communities Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 2. REGULATORY BACKGROUND Page 2-2 February 2011 are provided with sufficient flexibility to establish cost-effective CSO controls that meet the objectives and requirements of the CWA. The CSO Control Policy requires permitees to characterize their combined sewer systems and discharges, implement the nine minimum controls, and develop long-term CSO control plans to meet the technology-based and water quality-based requirements of the Clean Water Act. 2.4 Technology-Based Requirements The technology-based requirements for CSOs have been a matter of significant dispute during the development of MSD’s Long-Term Control Plan. 2.4.1 Federal Interpretation From the Federal perspective, the minimum technology-based requirements for CSOs are the nine minimum controls (see Table 2-1), as determined by the NPDES authority on a site-specific basis using best professional judgment. The establishment of site-specific controls must take into consideration the reasonableness of the relationship between the costs of attaining a reduction in the effluent and the effluent reduction benefits derived, the age of the equipment and facilities involved, the process employed, the engineering aspects of the various types of control techniques, process changes, and non- water quality environmental impact (including energy requirements). MSD implemented the nine minimum controls with appropriate documentation before January 1, 1997, and submits annual update reports to MDNR. • Proper operation and regular maintenance programs for the sewer system and CSO outfalls • Maximum use of the collection system for storage • Review and modification of pretreatment requirements to ensure that CSO impacts are minimized • Maximization of flow to the POTW for treatment • Elimination of CSOs during dry weather • Control of solid and floatable materials in CSOs • Pollution prevention programs to reduce contaminants in CSOs • Public notification to ensure the public receives adequate notification of CSO occurrences and CSO impacts • Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls Table 2-1 The Nine Minimum Controls for CSOs 2.4.2 State Interpretation For many years, State effluent regulations existed that MDNR interpreted as technology-based limits applicable to CSO outfalls. For receiving waters in St. Louis, former paragraphs (2)(B)3.E and (8)(B)3.E of 10 CSR 20 7.015 established weekly average effluent limits of 45 mg/l five-day biochemical oxygen demand (BOD5) and 45 mg/l non-filterable residue (NFR), and pH limits of 6 to 9, for discharges from “POTW wastewater treatment facilities providing at least primary treatment during a precipitation event and discharging on a non-continuous basis.” A higher NFR limit could be allowed for CSO treatment devices if organic solids were demonstrated to be an insignificant fraction of total inorganic storm- generated solids and the permittee could demonstrate that achieving the 45 mg/l limit was not cost- effective. During the mid-1990s, MDNR came to interpret these regulations as requiring either secondary treatment for all CSOs or their elimination by sewer separation. 2.4.3 MSD Response MSD developed and submitted its original Long-Term Control Plan in June 1999. That plan was based on the federal CSO Control Policy and supporting EPA guidance documents. The 1999 plan was Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 2. REGULATORY BACKGROUND Page 2-3 February 2011 ultimately not approved by MDNR as it did not provide for meeting secondary treatment requirements at all CSO outfalls in accordance with the State’s then-current technology-based requirements, as described above. Missouri’s Effluent Regulations have recently been modified such that they are in alignment with the Clean Water Act requirements for CSOs. This 2011 update to MSD’s original 1999 Long-Term Control Plan is therefore based upon the premise that the applicable technology-based requirements for CSOs are the Nine Minimum Controls as defined in the CSO Control Policy. 2.5 Water Quality-Based Requirements Discharges that remain after the implementation of CSO controls must not interfere with the attainment of water quality standards. Applicable water quality standards for the receiving streams in MSD’s combined sewer area are defined in Missouri’s Code of State Regulations, at 10 CSR 20 7.031. These water quality standards consist of designated beneficial uses, general or “narrative” requirements, specific or “numeric” water quality criteria for various parameters and pollutants, and anti-degradation requirements. The applicable water quality standards are described further in Section 3.3 of this report. In 2001, EPA issued guidance1 to address questions on how the development of long-term control plans should be integrated with water quality standards review. This guidance clarified that water quality standards could be changed, as appropriate, to ensure that communities could implement cost-effective CSO controls that would meet Clean Water Act requirements. 2.6 NPDES Permits (Missouri State Operating Permits) MSD’s CSO outfalls are permitted under two Missouri State Operating Permits: • MO-0025178 for the Bissell Point Wastewater Treatment Plant, and • MO-0025151 for the Lemay Wastewater Treatment Plant Each permit authorizes MSD to discharge from the CSO outfalls listed in that permit. Since April 30, 1993, MSD’s operating permits have contained requirements relative to CSOs: Permit Date CSO Requirement Submitted by MSD Approved by MDNR April 30, 1993 Submittal of CSO management plan in accordance with the Missouri CSO Strategy by June 30, 1993, followed by implementation of the plan June 30, 1993 November 9, 1993 November 8, 1996 Immediate implementation of the nine minimum controls N/A April 17, 1997 November 8, 1996 Submit documentation demonstrating compliance with the nine minimum controls by January 1, 1997 December 23, 1996 April 17, 1997 November 8, 1996 Completion of CSO Characterization, Monitoring and Modeling Program by January 1, 1997 December 23, 1996 April 17, 1997 November 8, 1996 Submittal of CSO Control Plan by June 30, 1999 June 30, 1999 Not Approved 1 Guidance: Coordinating CSO Long-Term Planning with Water Quality Standards Reviews, EPA-833-R-01-002, July 31, 2001. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 2. REGULATORY BACKGROUND Page 2-4 February 2011 2.7 Phased Long-Term Control Plan As noted previously, the June 1999 Long-Term Control Plan submitted by MSD was determined to be “not approvable” by MDNR in February 2002, as it did not provide for all CSO discharges to meet secondary treatment requirements in accordance with MDNR’s interpretation of its then-current effluent regulations. Following this disapproval, MSD and MDNR negotiated an agreement whereby MSD would prepare a CSO control plan in several phases, each of approximately a 5-year duration. MSD submitted a scope of work for preparing the phased plan on April 29, 2003. This scope of work, approved by MDNR on June 2, 2003, included an initial phase focusing on sewer separation, in lieu of secondary treatment, for up to 53 CSOs located primarily along urban streams. The initial phase of this plan was submitted to MDNR on June 23, 2004 and approved by MDNR on September 29, 2004. MSD immediately began implementing this plan. 2.8 EPA Section 308 Request for Information and Subsequent Litigation During the same time that the “phased plan” was being developed, MSD began meeting with EPA as part of that agency’s efforts to place all CSO communities under enforceable mechanisms (e.g., consent decrees). While the “phased plan” was still being reviewed by MDNR in 2004, MSD received a Section 308 Request for Information from EPA. This request directed MSD to update its 1999 Long- Term Control Plan in accordance with the federal CSO Control Policy. It also established various interim submittals that were to be made. These submittals have been made according to the schedule submitted by MSD in response to the Section 308 request and approved extensions. MSD was therefore simultaneously preparing two different CSO control plans: • For MDNR, MSD was preparing a “phased plan” consistent with Missouri’s interpretation of CSO technology-based requirements. This plan’s initial phase required separation of portions of the combined sewer system regardless of cost-performance considerations. • For EPA, MSD was preparing a Long-Term Control Plan consistent with the federal CSO Control Policy, which does not mandate combined sewer separation. The CSO Control Policy instead strives to ensure that CSO controls are cost-effective and meet the requirements of the Clean Water Act. MSD’s State Operating Permits, when they were revised on January 27, 2006, included a requirement for MSD to update its Long-Term Control Plan by August 17, 2006. An update to the “phased plan” then being implemented for the State was prepared and submitted to MDNR on August 16, 2006. This plan was rejected by EPA; no formal approval or rejection of the plan was made by MDNR. On June 11, 2007, the United States filed a complaint in U.S. District Court alleging, among other things, that MSD had failed to submit a Long-Term Control Plan in accordance with its operating permits and the Section 308 Request, and praying for injunctive relief and civil penalties. The State of Missouri joined the suit as a plaintiff. 2.9 Consent Decree The parties have since reached agreement through a mediation process. The enforceable parts of the Long-Term Control Plan presented in this report are embodied in Section VI (Implementation of CSO Control Measures and Post-Construction Monitoring) and Appendices D and E, including subsequent modifications, of the resulting Consent Decree. These enforceable provisions are included as Appendix R to this Long-Term Control Plan report. This Long-Term Control Plan updates the original 1999 plan. Certain control measures from the 2004 “phased plan” have been incorporated into this LTCP along with additional control measures to meet the requirements of the Clean Water Act and CSO Control Policy. The 2004 “phased plan” is no longer considered to be in effect. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-1 February 2011 3. EXISTING CONDITIONS 3.1 Combined Sewer Area 3.1.1 General Description MSD’s combined sewer area consists of 75 square miles comprising the entire City of St. Louis as well as portions of the adjacent inner ring of suburbs. Figure 3-1 depicts the location of the combined sewer area within MSD’s total service area. In addition to the 75 square miles that are served by combined sewers, approximately 14.5 square miles of separately-sewered area are tributary to the combined sewer system. Storm runoff generated in these areas enters the adjacent combined sewer system where it may contribute to the occurrence of wet weather overflows. These additional tributary area locations are shown on Figure 3-1. Figure 3-1 Combined Sewer and Tributary Areas Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-2 February 2011 Almost all of the northeastern portion of the combined sewer area, located within the Bissell Point service area, drains to the Mississippi River. A small portion of the Bissell Point combined sewer area, at its northern extent, drains to Maline Creek. All dry weather flows and a significant portion of wet weather flows are captured and conveyed for treatment at the Bissell Point Treatment Plant. The Bissell Point combined sewer area is further divided into subwatersheds as shown on Figure 3-2. Many of these subwatersheds (e.g., Mill Creek, Harlem, Branch, Baden) represent areas that were originally drained by smaller creeks that were covered and converted to combined sewers during the latter half of the 19th century and early 20th century. At present, there are no open drainage-ways or creeks in the Bissell Point combined sewer area located south of Maline Creek. Figure 3-2 Bissell Point Combined Sewer Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-3 February 2011 Most of the southwestern portion of the combined sewer area, located within the Lemay service area, drains to the River Des Peres or its tributaries. A small portion of the Lemay combined sewer area, at its eastern edge, drains to the Mississippi River. All dry weather flows and a significant portion of wet weather flows are captured and conveyed for treatment at the Lemay Treatment Plant. The Lemay combined sewer area is further divided into subwatersheds as shown on Figure 3-3. As previously discussed, many of these subwatersheds reflect areas that were originally drained by smaller creeks that were converted to combined sewers during the early 20th century. Figure 3-3 Lemay Combined Sewer Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-4 February 2011 3.1.2 Political Subdivisions The combined sewer area encompasses the 62-square-mile extents of the City of St. Louis as well as all or portions of 24 other municipalities, as depicted on Figure 3-4. Small portions of unincorporated St. Louis County are also contained within the combined sewer area. Several small pockets of combined sewers are located outside the limits of the general combined sewer area and are not shown on Figure 3-4. Table 3-1 lists the municipalities wholly or partially served by combined sewers, along with their total estimated populations and land areas. Additional municipalities, not listed in Table 3-1, exist within the 14.5 square mile separately-sewered areas that are tributary to the combined sewer system. Figure 3-4 Municipalities in the Combined Sewer Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-5 February 2011 Municipality Type Population (2000 census) Land Area (square miles) St. Louis City Constitutional charter 348,189 61.92 Bellefontaine Neighbors 4th class city 11,271 4.38 Beverly Hills 4th class city 603 0.09 Brentwood 4th class city 7,693 1.95 Clayton Constitutional charter 12,825 2.48 Country Club Hills 4th class city 1,381 0.18 Flordell Hills 4th class city 931 0.11 Glen Echo Park Village 166 0.03 Hillsdale Village 1,477 0.35 Jennings 3rd class city 15,469 3.69 Ladue 4th class city 8,645 8.59 Mackenzie Village 137 0.03 Maplewood Constitutional charter 9,228 1.55 Northwoods 4th class city 4,643 0.71 Pagedale 4th class city 3,616 1.20 Pasadena Hills 4th class city 1,147 0.23 Pine Lawn 4th class city 4,204 0.61 Richmond Heights Constitutional charter 9,602 2.29 Rock Hill 4th class city 4,765 1.09 Shrewsbury 4th class city 6,644 1.43 University City Constitutional charter 37,428 5.88 Uplands Park Village 460 0.07 Velda City 4th class city 1,616 0.16 Velda Village Hills Village 1,090 0.12 Wellston 3rd class city 2,460 0.90 Source: U.S. Census Bureau, Census 2000 Table 3-1 Municipalities in the Combined Sewer Area MSD owns and operates the public sewer system that collects and conveys combined wastewater and stormwater runoff from the areas encompassed by these municipalities. Control over the pervious and impervious surfaces that generate stormwater runoff, however, is not within MSD’s authority. The individual municipalities, either directly or through inter-jurisdictional agreements with other governments, control the local roadways and land use/zoning regulations that influence the generation of stormwater. Construction and maintenance of county and state roads through the combined sewer areas are similarly under the jurisdiction of other agencies – the St. Louis County Department of Highways and Traffic and the Missouri Department of Transportation. 3.1.3 Population The estimated population (year 2000 census) for MSD’s combined sewer area is 424,000. Another 34,000 people live in areas served by separate sewers wherein the storm runoff is tributary to the adjacent combined sewer system. Population changes in the combined sewer area are projected to be relatively minor during the time period of 2000 to 2035, according to data from the East-West Gateway Council of Governments. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-6 February 2011 3.1.4 Pollution Sources and Factors Affecting Runoff MSD does not have capacity-related dry-weather overflows from its combined sewer system. Overflows from the combined sewer system may occur during some wet-weather events when the combined flow of wastewater and stormwater exceeds the capacity of the system to convey and treat the flow. In addition to combined sewer overflows, other sources of pollution to area receiving streams may exist, including stormwater runoff from separate sewer areas, wet weather overflows from constructed sanitary sewer overflows (SSOs), failing septic tanks, permitted point source discharges from industrial/ commercial sources, and waste from pets and wildlife. The occurrence of wet weather overflows from MSD’s combined sewer system depends on the volumes and flow rates of runoff generated. Wet weather runoff from the combined sewer area is affected by a number of factors including topography, soils, land use and cover, and precipitation. Each of these factors is discussed below. 3.1.4.1 Topography The combined sewer area is comprised primarily of flat to gently-sloping terrain. Adjacent to the Mississippi River is a flat and fairly narrow floodplain, up to about one mile in width. Portions of the Lower River Des Peres and Maline Creek also exhibit small and narrow floodplains. Floodplain elevations are generally between 400 and 420 feet elevation above mean sea level. The Mississippi River floodplain located north of downtown St. Louis to Maline Creek is protected from high river conditions by a floodwall. A series of flood pump stations pump the interior drainage from this area that cannot flow to the river by gravity under river flood conditions. Downtown St. Louis is built on a bluff situated above the record flood elevation. South of the downtown area, to Cahokia Street, the low-lying floodplain is again protected by a floodwall and flood pump stations. From the floodplains, the land rises fairly rapidly to gently-sloping plains situated from 50 feet to a maximum of about 200 feet above the floodplain elevation. These plains generally slope to existing drainage-ways such as Maline Creek and the River Des Peres, or to former drainage-ways that were covered and converted to combined sewers in the latter half of the 19th and early 20th centuries. Land slopes are primarily low, from 0 to 5 percent, with a few areas of moderate, 5 to 15 percent, slopes. 3.1.4.2 Geology and Soils Bedrock underlying the St. Louis area consists primarily of Mississippian limestone/dolomite and Pennsylvanian shale and sandstone. Depth to bedrock can range from a few feet to over 100 feet. The upper layers of bedrock are often weathered and fractured. Karst features are present, particularly in the far southern portions of the combined sewer area, including large caves, solution channels, springs and sinkholes. Soils in the combined sewer area are generally classified as “Urban Land-Harvester-Fishpot Association.” This classification consists of urban land with nearly level to moderately steep slopes, and moderately well to somewhat poorly drained soils. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-7 February 2011 3.1.4.3 Land Use/Cover Existing land use in the combined sewer area is summarized in Table 3-2. Land Use Category Percent Residential 37.6 Industrial/Utility 4.8 Commercial 20.2 Recreational/Park 5.0 Institutional 3.5 Agricultural 0.0 Vacant/Undeveloped 0.7 Right-of-Way 17.4 Common Ground 10.8 Source: St. Louis City and St. Louis County parcel data. Table 3-2 Land Use in the Combined Sewer Area Large portions of the combined sewer area are comprised of residential properties, interspersed with commercial development along major roadways. Higher concentrations of industrial and commercial development exist in the areas adjacent to the Mississippi River, south of Interstate Highway 70 in the northwest corner of the city, in the central downtown area, and in the corridor along and between Interstate Highways 44 and 64. The amount of land cover with impervious surfaces has a significant impact on wet weather runoff quantities. In aggregate, public impervious surfaces such as roadways and sidewalks account for 14 percent of the total combined sewer area. Another 31 percent of the area represents private impervious surfaces such as roofs, driveways, parking lots, and patios. 3.1.4.4 Rainfall Characteristics On average, the St. Louis area receives 36.89 inches of precipitation in a typical year, based on hourly rainfall data from Lambert-St. Louis International Airport during the period of 1949 to 2005. Most of this precipitation falls as rain, but about 2 inches of water equivalent falls as snow in an average year. Precipitation in the St. Louis region is seasonal, with the three winter months being the driest. The spring months, March through May, are generally the wettest. Thunderstorms normally occur between 40 and 50 days per year, particularly during the late spring and summer months. Rainfall events in the St. Louis region can be classed into two general types – synoptic storms and cloudburst storms. Synoptic storms are characterized as large, area-wide storms that typically occur during the winter and early spring months. Their precipitation is of relatively long duration (e.g., 24 hours) with fairly uniform distribution over the impacted storm area. Cloudburst storms, by contrast, have a much smaller areal extent, occur more frequently during the spring and summer months, are of relatively short duration (typically 1 to 3 hours), and exhibit a non-uniform rainfall pattern with high intensity at the core of the thunderstorm and rapidly decreasing intensity as distance from the core increases. MSD has developed design storms that simulate both types of events – synoptic and cloudburst – for use in evaluating collection system performance during discrete events. EPA’s CSO Control Policy requires that the effectiveness of controls be evaluated on a system-wide annual average basis. MSD has selected the year 2000 as the year which best represents system-wide annual average precipitation conditions. Long-term average rainfall characteristics for St. Louis are presented in Table 3-3 and compared to the selected typical year 2000 statistics. As indicated in Table 3-3, the typical year chosen – Year 2000 – is very representative of average precipitation conditions. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-8 February 2011 Statistic Long-Term Average1 Year 2000 Annual rainfall (inches) 36.89 36.84 Total number of events2 102 98 - number > 0.1 inches 59 59 - number > 0.5 inches 23 27 - number > 1.0 inches 9 9 - number > 1.5 inches 4 4 - largest event (inches) 3.03 3.51 Average intensity (inches/hour) 0.073 0.075 Average event duration (hours)2 6.28 6.20 Average time between events (hours)2 80.9 86.9 Notes: 1. Lambert-St. Louis International Airport hourly data, 1949 to 2005. 2. Event statistics are based on a minimum 6-hour period between events without rain. Table 3-3 Average and Selected Typical Year St. Louis Rainfall Characteristics 3.2 Sewer Systems MSD maintains a complex network of sewers containing approximately 1,900 miles of combined sewers, 4,600 miles of sanitary sewers, and 3,100 miles of storm sewers. The age of these sewers ranges from less than a year old to over 150 years old. In general, combined sewers represent the older portions of the collection system; over 300 miles of combined sewers predate 1890 in their construction. The following subsections describe the combined sewer systems in the Bissell Point and Lemay service areas and their interrelationships, identify the locations of permitted CSOs, describe the two wastewater treatment plants that serve the combined sewer areas, and identify the long-term CSO controls that MSD has already implemented during the LTCP planning process. 3.2.1 Bissell Point Combined Sewer System The Bissell Point service area contains 88 square miles of land, representing about 17 percent of MSD’s total service area. As depicted on Figure 3-5, the area drains the northeastern half of the City of St. Louis and northeastern portions of St. Louis County. Combined sewers serve an area of approximately 40 square miles located primarily within the limits of the City of St. Louis, but extending beyond the City Limits in the Riverview, Harlem, and Baden subwatersheds. Separate storm and sanitary sewers serve the remainder of the Bissell Point area. Storm drainage from approximately 2.4 square miles of the separately sewered area is tributary to the combined sewer system. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-9 February 2011 Figure 3-5 Bissell Point Service Area The Bissell Point combined sewer system consists of 23 major subsystems. The trunk sewers in these subsystems are generally aligned perpendicular to the Mississippi River. Wastewater and stormwater from each of the subsystems are conveyed eastward through the trunk sewers to an interceptor tunnel that runs parallel to the Mississippi River, as shown on Figure 3-5. Flows from the separate sewer area enter the interceptor tunnel at its northern terminus at Maline Creek. Intercepted flows are treated at the Bissell Point Treatment Plant, a roughing filter/activated sludge secondary treatment facility. Wet weather flows in excess of treatment plant or interception capacity overflow from the trunk sewers by gravity or are pumped to the Mississippi River and Maline Creek, depending on river stage. The Bissell Point combined sewer system, particularly in areas near the Mississippi River, was heavily modified during the 1960s by two projects: • MSD’s Pollution Abatement Program, which added facilities to divert dry and some wet weather flows to the new Bissell Point Treatment Plant, and • The U.S. Army Corps of Engineer’s Mississippi River Flood Protection Project which provided flood protection to the City of St. Louis to a river stage of 52 feet. The outcome of these projects was a very complex combined sewer system incorporating both pollution control and flood control aspects into its design and operation. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-10 February 2011 A combined sewer subsystem in the Bissell Point service area typically consists of the following elements (illustrated in Figure 3-6): • A main trunk sewer conveying flows towards the receiving water. • One or more diversion structures (termed “interceptors” by MSD) that intercept and convey dry and some wet weather flows to treatment. • A deep tunnel that conveys intercepted dry and wet weather flow to the Bissell Point Treatment Plant. A series of pump stations and force mains were built to extend the interception system beyond the existing southern terminus of the tunnel. • A diversion structure to divert wet weather flows from the upper portions of the subsystem that are at a sufficiently-high elevation such that flow can be conveyed by gravity sewers even when the receiving water is under flood conditions. A “pressure sewer” conveys the diverted wet weather flows. • In certain instances “pressure sewers” are shared by more than one subsystem and “high level diversion sewers” are present to tie these subsystems together. • A flood pump station near the main trunk sewer outfall to pump wet weather flows from the lower portions of the watershed when the receiving water is under flood conditions. • In certain instances, floodwall pump stations may be shared by various subsystems and “low level diversion sewers” are present to connect the various trunk sewers together. • River gates that operate when the receiving water is at high or flood stage to prevent river backwater from causing flooding or interfering with collection system operation. Refer to the discussion of CSO operational modes in Section 3.2.4 for details on river gate operation. A detailed schematic of the Bissell Point combined sewer system that shows these various components for the entire system is contained in Appendix A. WWTP RIVER GATE RIVER GATE CSO OUTFALL CSO OUTFALLPRESSURE SEWERTRUNK SEWERFROM ADJACENT SUBSYSTEM VIA HIGH LEVEL DIVERSION SEWER FROM ADJACENT SUBSYSTEM VIA LOW LEVEL DIVERSION SEWER DRY WEATHER FLOW UPPER WATERSHED WET WEATHER FLOW TUNNEL BISSELL POINT PUMP STATION GATE FLOOD PUMP STATION INTERCEPTOR LOWER WATERSHED WET WEATHER FLOW WWTP RIVER GATE RIVER GATE CSO OUTFALL CSO OUTFALLPRESSURE SEWERTRUNK SEWERFROM ADJACENT SUBSYSTEM VIA HIGH LEVEL DIVERSION SEWER FROM ADJACENT SUBSYSTEM VIA LOW LEVEL DIVERSION SEWER DRY WEATHER FLOW UPPER WATERSHED WET WEATHER FLOW TUNNEL BISSELL POINT PUMP STATION GATE FLOOD PUMP STATION INTERCEPTOR LOWER WATERSHED WET WEATHER FLOW Figure 3-6 Typical Bissell Point Combined Sewer Subsystem Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-11 February 2011 In the Bissell Point service area there are 55 permitted combined sewer outfall locations, ranging in size from 24-inch diameter to 30 feet, which may discharge into receiving waters during periods of wet weather. Of these 55 CSOs, 50 are tributary to the Mississippi River and 4 to Maline Creek. The remaining CSO is tributary to Gingras Creek, approximately ¾ of a mile upstream of the creek’s juncture with the north branch or Gingras Creek Branch of the Baden Trunk combined sewer. The CSO locations, sizes and receiving waters are identified below in Table 3-4. Outfall Number Diameter or Size (W x H) Receiving Water Location 002 65 x 63 inch Mississippi River Foot of Dakota Street 003 126 x 126 inch arch Mississippi River Foot of Gasconade Street 004 132 inch Mississippi River Foot of President Street 005 72-inch Mississippi River Foot of Utah Street 006 96 x 108 inch Mississippi River Foot of Arsenal Street 007 90 inch Mississippi River Foot of Lynch Street 008 102 inch Mississippi River Foot of Victor Street 009 60 inch Mississippi River Foot of Barton Street 010 72 x 90 inch arch Mississippi River Foot of Trudeau Street 011 66 inch Mississippi River Foot of Lesperance Street 012 108 inch Mississippi River Foot of Carroll Street 013 46 x 61 inch Mississippi River Foot of Carroll Street 014 174 inch Mississippi River Foot of Miller Street 015 198 x 198 inch Mississippi River Foot of Rutger Street 016 324 inch wide channel Mississippi River Between Convent St. & Chouteau Ave. 017 36 inch Mississippi River Foot of Gratiot Avenue 018 30 inch Mississippi River Foot of Cedar Avenue 019 72 x 60 inch Mississippi River Foot of Poplar Street 020 60 x 60 inch Mississippi River Foot of Elm Street 021 30 inch Mississippi River Foot of Lucas Avenue 022 30 inch Mississippi River Foot of Delmar Street 023 30 inch Mississippi River Foot of Franklin Avenue 024 30 inch Mississippi River Foot of Cole Street 025 30 inch Mississippi River Foot of Carr Street 026 36 inch Mississippi River Foot of Carr Street 027 60 x 96 inch Mississippi River Foot of Biddle Street 028 30 inch Mississippi River Foot of O'Fallon Street 029 38 x 48 inch Mississippi River Foot of O'Fallon Street 030 30 x 40 inch Mississippi River Foot of Dickson Street 031 60 inch Mississippi River Foot of Florida Street 032 36 inch Mississippi River Foot of Brooklyn Avenue 033 48 x 60 inch Mississippi River Foot of Chambers Street 034 66 inch Mississippi River Foot of Madison Street 035 84 inch Mississippi River Foot of North Market St. 036 60 inch Mississippi River Foot of Benton Street 037 216 x 168 inch H.S. Mississippi River Foot of Palm Street 038 168 x 132 inch H.S. Mississippi River Foot of Branch Street 041 90 inch Mississippi River Foot of Salisbury Street 042 60 inch Mississippi River Foot of Bremen Avenue 043 96 x 120 inch Arch Mississippi River Foot of Ferry Street 044 78 inch Mississippi River Foot of Ferry Street 045 66 inch Mississippi River Foot of East Prairie Avenue 046 96 inch Mississippi River Foot of East Prairie Avenue 047 two 180 x 156 inch boxes Mississippi River Foot of East Taylor Avenue 048 120 x 102 inch H.S. Mississippi River Foot of Humboldt Avenue 049 three 108 x 192 inch boxes to 39-ft channel Mississippi River Between Thatcher and Calvary Avenues 050 60 inch Mississippi River Foot of Gimblin Street 051 376 inch wide channel Maline Creek Riverview Drive & Chain of Rocks Drive Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-12 February 2011 Outfall Number Diameter or Size (W x H) Receiving Water Location 052 42 and 60 inch Maline Creek 1100 ft downstream of Maline Dr. Shaft 053 42 inch Maline Creek Maline Creek just east of RR bridge 055 24 inch Mississippi River East of Water Works 057 36 inch Mississippi River Foot of Osceola Street 059 66 inch Gingras Creek 4658 San Diego Avenue 060 24 inch Maline Creek 9215 Riverview Drive 061 121 x 132 inch Mississippi River Foot of Biddle Street Table 3-4 Bissell Point CSO Outfalls 3.2.2 Lemay Combined Sewer System The Lemay service area contains 120 square miles of land, representing about 23 percent of MSD’s total service area. As depicted on Figure 3-7, the area drains the southwestern half of the City of St. Louis and portions of St. Louis County west and south of the City. Combined sewers serve an area of approximately 35 square miles located within the limits of the City of St. Louis, portions of south St. Louis County immediately adjacent to the Mississippi River, and various municipalities located west of the City of St. Louis including Clayton, University City, Brentwood, Richmond Heights, Maplewood, Pagedale and Wellston. Separate storm and sanitary sewers serve the remainder of the Lemay service area. Storm drainage from approximately 12.1 square miles of the separately sewered area is tributary to the combined sewer system. Figure 3-7 Lemay Service Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-13 February 2011 Although the Lemay combined sewer system has several subsystems that serve large areas, most subsystems are relatively small in size. Most of the subsystems are tributary to the River Des Peres, although a few are tributary to the Mississippi River. In addition, there are several flow interconnections between the Lemay and Bissell Point combined sewer systems. In areas tributary to the Mississippi River, wastewater and stormwater are conveyed eastward through trunk sewers to interceptor sewers and pump stations/force mains that run parallel to the Mississippi River. Intercepted flows are pumped to the Lemay Treatment Plant. Wet weather flows in excess of interception or treatment plant capacity overflow from the trunk sewers by gravity to the Mississippi River. In areas tributary to the middle and lower reaches of the River Des Peres, downstream of the Macklind Pump Station, wastewater and stormwater are conveyed toward the River Des Peres channel through trunk sewers. An interceptor sewer is located beneath the River Des Peres channel that intercepts dry and some wet weather flow for conveyance to the Lemay Treatment Plant via a pump station. Wet weather flows in excess of the River Des Peres interceptor sewer capacity overflow from the trunk sewers by gravity or are pumped to the River Des Peres, depending on location and river stage. The interceptor sewer beneath the River Des Peres channel also has several permitted overflow points. Wet weather flows that exceed the capacity of the pump station feeding the Lemay Treatment Plant may overflow from the interceptor sewer by gravity to the River Des Peres, or may overflow to the Mississippi River either by gravity or by pumping, again depending on river stage. In areas tributary to the upper reaches of the River Des Peres, or to the River Des Peres tributaries – Deer Creek, Black Creek, Hampton Creek, and Claytonia Creek – wastewater and stormwater are conveyed toward the stream channel through trunk sewers. Dry and some wet weather flows are intercepted and conveyed by gravity for treatment at the Lemay Treatment Plant. Wet weather flows in excess of interception or treatment capacity overflow by gravity to the receiving streams. Wastewater and stormwater that is collected, intercepted and conveyed for treatment in the Lemay service area is treated at the Lemay Treatment Plant, an activated sludge secondary treatment facility. A combined sewer subsystem in the Lemay service area typically consists of the following elements (illustrated in Figure 3-8): • A main trunk sewer conveying flows towards the receiving water. • One or more diversion structures (termed “interceptors” by MSD) that intercept and convey dry and wet weather flows to treatment. The interceptors are typically equipped with control gates only along the middle and lower segments of the River Des Peres. • Interceptor sewers that convey intercepted dry and wet weather flow to the Lemay Treatment Plant. • River gates at structures along the Lower and Middle River Des Peres and along the Mississippi River north of the River Des Peres that operate when the receiving water is at high or flood stage, to prevent river backwater from causing flooding or interfering with collection system operation. Refer to the discussion of CSO operational modes in Section 3.2.4 for details on river gate operation. Six of these gate structures along the Lower River Des Peres are also equipped with pumps to lift wet weather flows to the River Des Peres during flood conditions. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-14 February 2011 A detailed schematic of the Lemay combined sewer system that shows these various components for the entire system is contained in Appendix A. RIVER GATE CSO OUTFALLTRUNK SEWERDRY WEATHER FLOW INTERCEPTOR SEWER GATE INTERCEPTOR WET WEATHER FLOW TO WWTP RIVER GATE CSO OUTFALLTRUNK SEWERDRY WEATHER FLOW INTERCEPTOR SEWER GATE INTERCEPTOR WET WEATHER FLOW TO WWTP Figure 3-8 Typical Lemay Combined Sewer Subsystem In the Lemay service area there are 144 permitted combined sewer outfall locations, ranging in size from 12-inch diameter to 29 feet, that may discharge into receiving waters during periods of wet weather. Of these 144 CSOs, 10 discharge to the Mississippi River and the remainder to the River Des Peres and its tributaries. One permitted CSO, Outfall 157 to Gravois Creek, has recently been separated and will not be discussed further in this plan. The CSO locations, sizes and receiving waters are identified below in Table 3-5. Outfall Number Diameter or Size (W x H) Receiving Water Location 008 60 inch Lower River Des Peres Marceau & Alabama 009 48 inch Lower River Des Peres Poepping & Carondelet 010 three 68 x 167 inch Lower River Des Peres Germania & Primm 011 72 x 72 inch Lower River Des Peres Germania & Fields 012 42 inch Lower River Des Peres Germania & Yates 013 78 inch Lower River Des Peres Carondelet & West Primm 014 48 inch Lower River Des Peres Germania east of Morgan Ford 015 three 68 x 120 inch Rock Creek Rock Creek south of Loughborough 016 24 inch Rock Creek Rock Creek at Parkwood & Steins 017 42 inch Lower River Des Peres Carondelet west of Morgan Ford 018 36 inch Lower River Des Peres Germania & Tesson 019 30 inch Lower River Des Peres Germania & Stolle 020 36 inch Lower River Des Peres 4800 River Des Peres Blvd 021 60 inch Lower River Des Peres River Des Peres at Gravois Avenue 022 60 inch Lower River Des Peres 400-ft west of Gravois Avenue 023 three 68 x 168 inch Lower River Des Peres 1,000-ft SW of Jamieson & Loughborough 024 108 x 36 inch Lower River Des Peres River Des Peres at Mackenzie Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-15 February 2011 Outfall Number Diameter or Size (W x H) Receiving Water Location 025 48 inch Lower River Des Peres Westway & Willmore 026 42 inch Lower River Des Peres River Des Peres east of Chippewa 027 156 x 61 inch Lower River Des Peres McCausland & Delor 028 42 inch Lower River Des Peres McCausland & Wabash 029 78 inch Lower River Des Peres Lansdowne & Wabash 030 54 x 59 inch Lower River Des Peres River Des Peres at Mardel 031 30 inch Lower River Des Peres Pernod & Wabash 032 84 x 40 inch Lower River Des Peres River Des Peres at Deer Creek 036 36 inch Middle River Des Peres Manhattan & Ellendale Avenue 037 48 x 48 inch Middle River Des Peres 900-ft south of Arsenal Street 039 84 inch Middle River Des Peres 250-ft south of Arsenal Street 041 two 36 x 48 inch Middle River Des Peres River Des Peres at Canterbury Avenue 042 two 48 x 84 inch Middle River Des Peres River Des Peres at Arsenal Street 043 two 108 x 72 inch Middle River Des Peres 250-ft north of Arsenal Street 044 48 x 48 inch Middle River Des Peres River Des Peres at Southwest Avenue 046 15 inch Middle River Des Peres 6703 Southwest Avenue 048 two 36 x 54 inch Middle River Des Peres 2,000-ft north of Southwest Avenue 049 15 inch Middle River Des Peres 2,200-ft N of Southwest Avenue 050 108 x 84 inch Middle River Des Peres 500-ft SE of Mitchell & Manchester 052 two 48 x 84 inch Middle River Des Peres 500-ft west of Knox Avenue 053 84 inch Middle River Des Peres River Des Peres at Knox Avenue 054 60 x 66 inch Middle River Des Peres 250-ft west of Sulphur Avenue 057 two 48 x 100 inch Middle River Des Peres NW corner of Sublette Avenue 058 108 x 74 inch Middle River Des Peres SE corner of Sublette Avenue 061 30 inch Middle River Des Peres Macklind Avenue 062 21 inch Middle River Des Peres 250-ft east of Macklind Avenue 063 two 29-ft and one 16-ft horseshoes Middle River Des Peres River Des Peres at Macklind Pump Sta. 064 30 inch Upper River Des Peres River Des Peres north of Olive Blvd 066 21 inch Upper River Des Peres Kingsland Avenue & Alley south of Etzel 067 21 inch Upper River Des Peres Etzel & Kingsland Avenues 068 36 inch Upper River Des Peres River Des Peres at Etzel 069 21 inch Upper River Des Peres River Des Peres at Ursula & Corbitt 070 33 inch Upper River Des Peres River Des Peres at Midway & Belrue 071 24 inch Upper River Des Peres River Des Peres at Ferguson Avenue 072 42 x 52 inch Upper River Des Peres River Des Peres at Ferguson Avenue 073 18 inch Upper River Des Peres River Des Peres at Melrose Avenue 074 24 inch Upper River Des Peres West of Ferguson Avenue 075 24 inch Upper River Des Peres River Des Peres at Raymond Avenue 076 21 inch Upper River Des Peres River Des Peres at Roberts Avenue 077 30 inch Upper River Des Peres Pennsylvania & Page Avenues 078 27 inch Upper River Des Peres River Des Peres at Vernon & Ferguson 079 72 inch Upper River Des Peres 300-ft SE of Pennsylvania & Vernon 080 24 inch Upper River Des Peres River Des Peres at Radcliff 081 66 inch Upper River Des Peres Pennsylvania & Dartmouth 082 42 inch Upper River Des Peres Pennsylvania & Vernon 083 72 inch Upper River Des Peres River Des Peres 150-ft south of Purdue 084 78 inch Upper River Des Peres River Des Peres at Vernon & Midland 085 60 inch Upper River Des Peres River Des Peres at Purdue 086 84 x 120 inch Upper River Des Peres Olive, East of Midland Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-16 February 2011 Outfall Number Diameter or Size (W x H) Receiving Water Location 087 18 inch Upper River Des Peres River Des Peres at Purdue 088 24 inch Upper River Des Peres River Des Peres at Shaftesbury Avenue 089 36 inch Upper River Des Peres 150-ft west of Hanley Rd 090 30 inch Upper River Des Peres Balson and North & South Road 091 72 inch Upper River Des Peres Balson and North & South Road 092 120 x 70 inch Upper River Des Peres Amherst and North & South Road 093 27 inch Upper River Des Peres 100-ft east of North & South Road 094 27 inch Upper River Des Peres River Des Peres at Wild Cherry 095 30 inch Upper River Des Peres River Des Peres at Shaftesbury Avenue 096 36 inch Upper River Des Peres River Des Peres at Mona & Mt. Olive 099 36 inch Upper River Des Peres River Des Peres at Olivette & Westover 100 27 inch Upper River Des Peres River Des Peres at Wayne 101 33 inch Upper River Des Peres River Des Peres north of Milan Drive 102 96 x 96 inch Upper River Des Peres 150 ft southwest of end of Briscoe Pl. 103 two 72 x 72 inch Deer Creek 7140 Wellington 104 55 x 65 inch Deer Creek Deer Creek 400-ft SE of Big Bend Blvd. 105 42 inch Deer Creek Deer Creek at Laclede Station Road 106 96 x 60 inch Deer Creek 2780 Mary Avenue 107 36 inch Deer Creek 9418 Tilles 108 18 inch Deer Creek Waverton and Magnolia Drives 110 30 inch Black Creek North Swan Circle and Wrenwood Lane 111 84 inch Black Creek Brentwood and Red Bud Ave. 112 42 inch Black Creek McKnight Road SE of US 40 114 15 inch Black Creek Clayton Road and Haddington Ct. 115 30 inch Black Creek 801 Wennecker 116 24 inch Black Creek 7 Ladue Forest Lane 117 42 inch Black Creek 7965 Manchester 118 48 inch Hampton Creek Hampton Creek north of West Point Cir. 119 27 inch Hampton Creek Hampton Creek at Laclede Forest Drive 120 18 inch Hampton Creek Hampton Creek at Alicia Court 121 66 inch Hampton Creek Hampton Creek at Alicia Court 122 24 inch Claytonia Creek Claytonia Creek at 7715 Bruno Avenue 123 24 inch Claytonia Creek Claytonia Creek at 7700 Weston 124 54 inch Claytonia Creek Claytonia Creek at 1516 Collins 125 30 inch Claytonia Creek Claytonia Creek at 1501 Claytonia 126 30 inch Claytonia Creek Claytonia Creek at 7615 Dale Avenue 127 15 inch Claytonia Creek Claytonia Creek at 7615 Dale Avenue 128 72 inch Claytonia Creek Claytonia Creek at 1123 Claytonia Ter. 130 72 x 62 inch Claytonia Creek Claytonia Creek at Clayton Road 131 24 inch Hampton Creek Hampton Creek at Laclede Station Rd 134 30 inch Hampton Creek Hampton Creek at U.S. Highway 40 135 24 inch Hampton Creek Hampton Creek 300-ft north of South Dr 136 48 inch Hampton Creek Hampton Creek 400-ft south of Park Dr. 137 24 inch Hampton Creek Hampton Creek 300-ft north of South Dr 138 18 inch Hampton Creek Hampton Creek 1100-ft south of Park Dr. 139 18 inch Hampton Creek Hampton Creek at Park Drive 140 15 inch Hampton Creek Hampton Creek at Park Drive 141 72 x 72 inch Hampton Creek Hampton Creek at Clayton Road 142 two 72 x 96 inch Mississippi River Foot of Fillmore St. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-17 February 2011 Outfall Number Diameter or Size (W x H) Receiving Water Location 143 60 inch Mississippi River Foot of Quincy Street 144 48 inch Mississippi River Foot of Upton St. 147 108 inch Mississippi River Foot of Catalan Avenue 149 36 inch Mississippi River East of River & Grant Roads 151 33 inch Mississippi River East of River Road & Smith Avenue 152 58 x 58 inch Mississippi River East of River Road & Kearney Ave. 153 42 inch Mississippi River Northeast of North Gate Dr. & East Cir. 154 12 inch Mississippi River East of South Circle & Jefferson Drive 157 54 inch Gravois Creek tributary 2567 Rosegarden 160 15 inch Black Creek 10 Greenbriar Drive 161 36 inch Deer Creek NW of Interceptor at 2737 McKnight Rd 163 72 x 48 inch Lower River Des Peres Acorn & Staley 164 12 inch Deer Creek tributary Behind 24 Deer Creek Woods Drive 165 15 inch Deer Creek tributary Behind 20 Deer Creek Woods Drive 166 66 inch Deer Creek 3622 Big Bend Ind. 167 24 inch Upper River Des Peres 6416 Page 168 48 inch Lower River Des Peres Lansdowne & Chippewa 170 four 42 inch Lower River Des Peres 8514 Virginia Avenue 171 24 x 36 inch Lower River Des Peres River Des Peres at Sutherland 172 24 x 36 inch Lower River Des Peres River Des Peres 400 feet S of Watson 173 six 6 inch Lower River Des Peres River Des Peres at Lindenwood 174 12 inch Black Creek 9 Edgewood Road 175 66 inch Black Creek Galleria Shopping Center 176 15 inch Hampton Creek 2650 Hanley 177 15 inch Middle River Des Peres 6767 Southwest Avenue 178 18 inch Upper River Des Peres 7171 Page 179 two 120 x 96 boxes Mississippi River Mississippi River at Bates St. 180 24 inch Upper River Des Peres 6959 Dartmouth 181 21 inch Lower River Des Peres 4661 Hamburg Avenue Table 3-5 Lemay CSO Outfalls 3.2.3 Interrelationships of Systems There are three locations where the Lemay and Bissell Point combined sewer systems are interconnected: • Park and Thurman Avenues – The interconnection at Park and Thurman is the more significant of the service area interconnections. Dry weather flow from the Tower Grove subsystem is diverted by a dam at Park and Thurman Avenues into the Mill Creek subsystem (Bissell Point service area). Wet weather flows from the Tower Grove subsystem are also conveyed to the Mill Creek subsystem until the diversion dam is topped. At this point, the excess wet weather flow topping the dam is conveyed by a 16-ft horseshoe sewer to the River Des Peres at Outfall 063. • Macklind Pump Station – The Macklind Pump Station allows flows collected from the diversion structures at Lemay Outfall 063 to be pumped into the Tower Grove subsystem and diverted as described above. The pump station is primarily utilized to divert dry weather flows during maintenance operations on the interceptor sewer downstream of Outfall 063. • West Pine Boulevard – Two relatively minor interconnections exist in the vicinity of West Pine Boulevard and Kingshighway Boulevard by which dry weather flows from the Clarendon and Euclid subsystems (Lemay service area) are diverted into the Mill Creek subsystem (Bissell Point service Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-18 February 2011 area). Most of the wet weather flow from the Euclid subsystem continues on to the River Des Peres; the Clarendon diversion sends most wet weather flow to the Bissell Point system. 3.2.4 CSO Operational Modes The combined sewer system is an integral part of St. Louis’ flood protection system. Consequently, river stage can play an important role in the operation and performance of those portions of the combined sewer system that are influenced by high river conditions: outfalls located along the Mississippi River, and along the River Des Peres from the Mississippi River to the Macklind Pump Station. CSO outfalls at other locations do not have river gates or pump stations, although some do have flap gates or check valves that prevent backflow of receiving water into the collection system. There are three distinct modes of system operation for the susceptible combined sewer areas, depending on river stage: 1) low river mode, 2) Overflow Regulation System (ORS) mode, and 3) flood mode. The following figures depict the different modes of operation for a typical outfall and indicate how river stage can influence CSO outfall performance. Figure 3-9 depicts the low river mode. Under low river stage conditions, the river closure gates remain open at all times. Dry weather flows are intercepted for treatment, but during wet weather, flows that exceed interception capacity overflow to the river. RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE LOW RIVER MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE LOW RIVER MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE LOW RIVER MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE LOW RIVER MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE LOW RIVER MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE LOW RIVER MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE LOW RIVER MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE REMAINS OPEN WHEN RIVER IS LOWER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE LOW RIVER MODE – WET WEATHER PUMP STATION NOT IN OPERATION Figure 3-9 CSO Operation - Low River Mode Figure 3-10 depicts the ORS mode, which begins when the river stage exceeds the elevation of the diversion structure or interceptor. During locally-dry weather, the river closure gate is kept closed to allow all dry weather flows to be intercepted for treatment and to prevent the river from inundating the system. During locally-wet weather, the river closure gate is kept closed until wet weather flows exceed the interceptor capacity and cause the level in the outfall sewer to rise higher than the river level. The river closure gate then partially or fully opens until the sewer level falls. At the end of the wet weather event, the river closure gate closes and remains closed until the river falls below the interceptor elevation. All stored flow in the outfall sewer (i.e., flows between the river level and the interceptor elevation) drains back through the interceptor to treatment. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-19 February 2011 RIVER CLOSURE GATE GATE CLOSES WHEN RIVER IS HIGHER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE ORS MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE CLOSES WHEN RIVER IS HIGHER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE ORS MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE OPENS WHEN SEWER LEVEL IS HIGHER THAN RIVER LEVEL INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE ORS MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE OPENS WHEN SEWER LEVEL IS HIGHER THAN RIVER LEVEL INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE ORS MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE CLOSES WHEN RIVER IS HIGHER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE ORS MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE CLOSES WHEN RIVER IS HIGHER THAN INTERCEPTOR DAM INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE ORS MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE OPENS WHEN SEWER LEVEL IS HIGHER THAN RIVER LEVEL INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGE ORS MODE – WET WEATHER PUMP STATION NOT IN OPERATION RIVER CLOSURE GATE GATE OPENS WHEN SEWER LEVEL IS HIGHER THAN RIVER LEVEL INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP RIVER STAGERIVER STAGE ORS MODE – WET WEATHER PUMP STATION NOT IN OPERATION Figure 3-10 CSO Operation - ORS Mode The final CSO mode, flood mode, is shown in Figure 3-11. Flood mode of operation begins when the river stage exceeds a level where locally-wet weather flows can no longer flow by gravity to the river without flooding basements or low-lying areas. During locally-dry weather, the river closure gate is kept closed to allow all dry weather flow to be intercepted for treatment and to prevent the river from inundating the system. During locally-wet weather, the river closure gate is kept closed, and wet weather flows that exceed the interceptor capacity are pumped to the river. At the end of the wet weather event, the river closure gate remains closed and all stored flow in the outfall sewer (i.e., between the “pump- off” level and the interceptor level) drains back through the interceptor to treatment. RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER STAGERIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – WET WEATHER PUMP STATION PUMPS WET WEATHER FLOW TO RIVER RIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – WET WEATHER PUMP STATION PUMPS WET WEATHER FLOW TO RIVER RIVER STAGERIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – DRY WEATHER PUMP STATION NOT IN OPERATION RIVER STAGERIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – WET WEATHER PUMP STATION PUMPS WET WEATHER FLOW TO RIVER RIVER STAGE RIVER CLOSURE GATE GATE CLOSED WHEN RIVER EXCEEDS FLOOD-MODE STAGE INTERCEPTOR INTERCEPTOR GATE OPEN OR THROTTLED INTERCEPTOR DAM INTERCEPTOR SEWER TO WWTP FLOOD MODE – WET WEATHER PUMP STATION PUMPS WET WEATHER FLOW TO RIVER RIVER STAGERIVER STAGE Figure 3-11 CSO Operation - Flood Mode 3.2.5 Treatment Plants and Pump Stations 3.2.5.1 Bissell Point Treatment Plant The Bissell Point Treatment Plant is a secondary treatment facility located adjacent to the Mississippi River on East Grand Avenue. Wastewater is conveyed to the plant by an interceptor tunnel with two branches, one stretching 4.3 miles to the north of the treatment plant, the other 5.6 miles to the south. The influent pumping and preliminary and primary treatment systems are designed and permitted to handle a flow of 350 MGD, matching the wet weather conveyance capacity of the interceptor tunnel. The secondary treatment facilities are designed and permitted for a flow of 250 MGD. Dry weather flows average 110 MGD but can vary from 75 to 150 MGD depending on groundwater and river levels. During wet weather, the flow rate to the treatment plant can increase to 350 MGD. As the secondary treatment facilities are limited to a flow of 250 MGD, up to 100 MGD of primary effluent is Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-20 February 2011 blended with the secondary effluent under these conditions. The major treatment components are illustrated on Figure 3-12 and described below. PUMP STATION NO. 1 TO MISSISSIPPI RIVER PRIMARY SETTLING GRIT REMOVAL & COMMINUTION PRE- AERATION SYNTHETIC MEDIA TRICKLING FILTERS AERATION SECONDARY SETTLING EFFLUENT PUMP STATION FLOW IN EXCESS OF 250 MGD COARSE SCREENING RAW SEWAGE Figure 3-12 Bissell Point Treatment Plant Schematic • Influent Screening. Two mechanically cleaned bar screens with a clear opening of 2½-inches remove coarse solids from the wastewater prior to pumping. • Influent Pumping. Five 70,000 gpm pumps (two constant and three variable speed) lift screened wastewater from the interceptor tunnel to the treatment plant. • Grit Removal. Six 55-ft square detritus tanks remove grit and heavier solids from the influent wastewater. Each tank can handle approximately 80 MGD at the design maximum flow-through velocity of 0.5 ft/sec. • Comminution. Seven 60 MGD submerged rotary-type comminutors, with space for an eighth, shred coarse floating solids in the wastewater. Two manually cleaned bypass bar screens are provided for emergency use. • Preaeration. Four two-pass preaeration tanks are provided to preaerate the wastewater prior to primary settling. Each pass has dimensions of approximately 23 feet wide by 152.5 feet long and 15 feet deep, providing a total volume of 412,000 cubic feet in the four tanks. • Primary Settling. Eight rectangular settling tanks, each 86 feet wide by 312 feet long and 13 feet deep with a maximum flow capacity of 50 MGD, are provided for primary clarification. • Primary Effluent Pumping. Six constant speed, 40 MGD vertical turbine pumps are provided along with two variable speed, 50 to 90 MGD pumps to lift primary effluent to the trickling filters. • Trickling Filters. Six 134-foot diameter trickling filters, with 32-ft media depth, provide treatment of the wastewater prior to activated sludge treatment. Each trickling filter can handle up to 50 MGD flow. • Aeration. Six 30-foot deep aeration basins with fine bubble diffusers aerate the activated sludge mixed liquor. The basins are designed to operate in either a complete-mix/plug-flow mode or a sludge-reaeration/complete-mix/plug-flow mode. Currently the aeration tanks are not in operation. • Final Settling. Twelve 150-foot diameter settling tanks, each with a design average capacity of 12.5 MGD, provide final settling of the wastewater prior to discharge to the Mississippi River. Sludge removed from the settling tanks is wasted to the primary settling tanks for thickening. • Effluent Pumping/Discharge. Three 60,000 gpm submersible propeller-type pumps lift treated effluent to the Mississippi River when the river exceeds stage 33. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-21 February 2011 • Biosolids Management. Waste primary and secondary sludge is dewatered on fifteen 2 meter wide belt filter presses, and incinerated in six multiple-hearth incinerators each with a design capacity of approximately 10 tons of wet sludge per hour. Residual ash is landfilled. 3.2.5.2 Lemay Treatment Plant The Lemay Treatment Plant is a secondary treatment facility located adjacent to the Mississippi River just south of the River Des Peres. Wastewater from the majority of the Lemay service area is conveyed through an interceptor sewer located beneath the River Des Peres channel to the Lemay No. 1 Pump Station. Wastewater from the southeastern part of the service area is conveyed through a series of interceptor sewers, pump stations and force mains to the Lemay No. 3 Pump Station. Wastewater is conveyed by force mains from the Lemay No. 1 and No. 3 Pump Stations to the treatment plant. The preliminary and primary treatment systems are designed to handle a flow of 340 MGD, matching the wet weather conveyance capacity of the interceptor sewers. The secondary treatment facilities are designed for a flow of 167 MGD. Dry weather flows average 96 MGD but can vary from 75 to 130 MGD depending on groundwater and river levels. During wet weather, the flow rate to the treatment plant can increase above the 167 MGD capacity of the secondary treatment facilities. Excess primary effluent is blended with the secondary effluent under these conditions. The major treatment components are illustrated on Figure 3-13 and described below. PUMP STATION NOS. 1 & 3 TO MISSISSIPPI RIVER PRIMARY SETTLING GRIT REMOVAL & COMMINUTION AERATION SECONDARY SETTLING FLOW IN EXCESS OF 167 MGD RAW SEWAGE COARSE SCREENING Figure 3-13 Lemay Treatment Plant Schematic • Influent Screening. Two mechanically cleaned bar screens with a clear opening of 2½-inches remove coarse solids from the wastewater at Lemay Pump Station No. 1. • Influent Pumping. Six 38,500 gpm pumps deliver screened wastewater from Pump Station No. 1 to the Lemay Treatment Plant. Pump Station No. 3 serves areas along the Mississippi River with three 8,000 gpm pumps. The combined capacity of the pump stations is currently 290 MGD and will be expanded to 340 MGD. • Preliminary and Primary Treatment. Four 55-ft square detritus tanks remove grit and heavier solids from the influent wastewater. Each tank can handle approximately 75 MGD at the design maximum flow-through velocity of 0.5 ft/sec. Degritted wastewater is fed through five 60 MGD submerged rotary-type comminutors. Two 2-pass preaeration tanks are provided to preaerate the wastewater Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-22 February 2011 prior to primary settling in eight rectangular settling tanks, each 80 feet wide by 268 feet long with a maximum flow capacity of 40 MGD. Paralleling the above-described treatment facilities are two 35-ft square detritus tanks with channel grinders, and four 133-ft diameter primary clarifiers. The combined capacity of these two treatment trains is 340 MGD. • Aeration. Eight 4-pass aeration tanks are operated in a sludge-reaeration/step-feed mode. Six of the eight aeration basins are equipped with fine bubble diffusers; the other two basins have coarse bubble diffusers and are used only for emergency situations. • Final Settling. Twelve 150 foot diameter settling tanks provide final settling of the wastewater prior to discharge to the Mississippi River. Sludge removed from the final settling tanks is either recycled back to the reaeration pass of the aeration tanks or wasted to the primary settling tanks for thickening. • Effluent Discharge. Treated secondary effluent is discharged by gravity through a new 132-inch diameter outfall, currently under construction, to the Mississippi River. • Biosolids Management. Waste primary and secondary sludge is dewatered on six 2-meter wide belt filter presses, and incinerated in four multiple-hearth incinerators each with a design capacity of approximately 10 tons per hour of wet sludge. Residual ash is landfilled. 3.2.6 CSO Controls Implemented During Planning During the LTCP planning process, MSD implemented several long-term CSO controls that have resulted in substantial reductions in CSO overflow volume and pollutant loadings: • Overflow Regulation Systems in the Bissell Point and Lemay service areas, • Treatment plant and pump station improvements, • Conveyance system modifications, • Industrial waste separations, and • Combined sewer separations. These controls are an integral part of MSD’s Long-Term Control Plan. The controls have cost MSD approximately $0.6 billion in 2007 dollars and have reduced typical year overflow volumes by 7.8 billion gallons. The following subsections describe the controls, their benefits, and costs. 3.2.6.1 Overflow Regulation Systems The Bissell Point Overflow Regulation System and the Lemay Overflow Regulation System were constructed to significantly reduce the influence of Mississippi River stage on the operation of the combined sewer system. The Bissell Point and Lemay projects were completed in 1998 and 2006, respectively. The basic features of the systems include the following: • Automatically-controlled closure gates or backflow gates were provided on outfalls to the Mississippi River, and to the River Des Peres below the Macklind Pump Station. These gates prevent the river from inundating the interceptors, thereby permitting the interceptor gates to remain open and intercept flows during high river level conditions. • The lower reaches of the trunk sewers were structurally improved to resist the external hydrostatic forces imposed when the sewer closure gates are closed and the groundwater elevation is high due to river influence. • Interceptor bar grates were modified or eliminated, and small interceptor pipes replaced with larger ones to help eliminate blockage and improve interception capacity. • Instrumentation and controls were provided to allow monitoring and control of the entire overflow regulation system. • Temporary flood pump stations were replaced with permanent facilities. The operation of these features was previously described in Section 3.2.4. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-23 February 2011 The overflow regulation systems have provided two major benefits. They have significantly reduced and in many cases eliminated combined sewer overflows that formerly resulted from wet weather-related high river conditions. The systems also provide a modest amount of additional system storage under high river conditions. The volume in the collection system between the interceptor elevation and the closure gate or flood pump control elevation is available and used for storage of wet weather flow. The runoff from small storms may be completely contained by this volume, eliminating overflows entirely; the runoff from larger storms is partially stored. The total capital costs of the Bissell Point and Lemay Overflow Regulation Systems were $154 million and $170 million, respectively, in 2007 dollars. The estimated benefits provided by the systems are summarized below: Estimated Annual Overflow Reduction Parameter Units Bissell Point Lemay Flow million gallons 4,313 197 BOD5 million lbs 3.81 0.17 TSS million lbs 6.43 0.21 Table 3-6 Benefits of Overflow Regulation Systems 3.2.6.2 Treatment Plant and Pump Station Improvements Significant improvements were constructed at the Bissell Point Treatment Plant to allow the facility to utilize excess preliminary and primary treatment capacity. The improvements consisted of repairs to the concrete grit tanks and primary settling tanks; repairs and replacements of grit removal and handling equipment, comminutors, and clarifier mechanisms; automation of equipment control systems; and provision of appropriate hydraulic diversion structures. These plant improvements went on line in 1997 and allowed wet weather flows of 350 MGD to be treated through the preliminary and primary treatment facilities, and 250 MGD through the secondary treatment facilities. Formerly, flows to the plant were limited to a maximum of 250 MGD. Several operational improvements have also been implemented during the period 1997 to 2006 at the pump station feeding the treatment plant. The improvements include drawdown of the pump station wet well prior to wet weather events, and the use of flow-control set-points instead of level-control set-points during wet weather pumping operations. Improvements were also made at the Lemay Treatment Plant (including new diversion chambers, detritus tanks and primary clarifiers) to allow up to 340 MGD of wet weather flow to be treated through preliminary and primary treatment facilities and 167 MGD through secondary treatment facilities. Influent pump station improvements and a new plant outfall are not yet completed, limiting peak influent flows at present to 290 MGD. The total capital costs of the Bissell Point and Lemay improvements were $18 million and $150 million, respectively, in 2007 dollars. The improvements have resulted in the following estimated benefits: Estimated Annual Overflow Reduction Parameter Units Bissell Point Lemay Flow million gallons 1,691 1,176 BOD5 million lbs 1.87 0.87 TSS million lbs 4.24 1.75 Table 3-7 Benefits of Treatment Plant and Pump Station Improvements Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-24 February 2011 3.2.6.3 Conveyance System Modifications Approximately 12.1 square miles of land at the upper reaches of the River Des Peres are served by separate sanitary and storm sewers. Prior to 2000 the separate sanitary flows from this area were conveyed to the enclosed section of the River Des Peres near Forest Park, a combined sewer. During wet weather events, the separate sanitary flows from the upper reaches of the watershed would therefore combine with storm flows in the combined sewer, and overflow at Outfall 063 near the Macklind Pump Station. Recognizing the benefit of removing these separate sanitary flows from the combined collection system, MSD in late 1996 began construction of the Skinker-McCausland Tunnel. The tunnel consists of a 78-inch diameter reinforced concrete pipe sewer, constructed in tunnel, extending from the vicinity of Arsenal Street and the River Des Peres channel, north along McCausland and Skinker Avenues, and then west and north to near Olive Boulevard and 82nd Street. The separate sanitary sewer systems were then connected to the tunnel. The tunnel, completed at a capital cost of $69 million in 2007 dollars, express routes sanitary flows from the separately sewered areas of the Upper River Des Peres subwatershed directly to the interceptor sewer beneath the Lower River Des Peres, and thence to the Lemay Treatment Plant. The estimated annual reduction in combined sewer overflow volume and loadings are summarized below. Parameter Units Estimated Annual Overflow Reduction Flow million gallons 337 BOD5 million lbs 0.19 TSS million lbs 0.94 Table 3-8 Benefits of Skinker-McCausland Tunnel 3.2.6.4 Industrial Waste Separations The Bissell Point service area contains several large industrial wastewater sources. At one time, as much as half of the organic loading to the Bissell Point Treatment Plant originated from a single industrial source. Early in the CSO control planning process, it was recognized that significant portions of these industrial waste loads could overflow to the Mississippi River during wet weather events, and that efforts to directly connect large industrial sources to the Bissell Point Interceptor Tunnel would have environmental benefits. Two major industrial wastewater sources have been disconnected from the combined sewer system in recent years. Wastewater from these facilities is now directly conveyed to the Bissell Point Interceptor Tunnel. A third industrial wastewater source that was directly connected to the tunnel has been abandoned in recent years. • Since late 1996, wastewater flows from the Anheuser-Busch InBev brewery in south St. Louis have been disconnected from the combined sewer system. These flows now discharge through a pretreatment plant and then directly to the Barton Dropshaft of the Bissell Point Interceptor Tunnel. Removing these wastewaters from the combined sewer system has reduced the discharge of organics, solids, and other pollutants in combined sewer overflows. • Mallinckrodt Inc., which manufactures specialty chemicals and pharmaceuticals at its plant in north St. Louis, also disconnected its wastewater flow from the combined sewer system in 1996. Mallinckrodt now routes this flow through a pretreatment plant and then directly to the Salisbury Access Shaft of the Bissell Point Interceptor Tunnel. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-25 February 2011 The estimated benefits of removing these industrial flows from the combined sewer system are summarized below. Estimated Annual Overflow Reduction Parameter Units Anheuser-Busch InBev Mallinckrodt Inc. Flow million gallons 7.6 4.2 BOD5 million lbs 0.14 0.015 TSS million lbs 0.06 0.007 Table 3-9 Benefits of Industrial Waste Separations 3.2.6.5 Combined Sewer Separations Several small CSOs have been separated in recent years; additional separations are currently under design and construction. Many of these CSO separation projects originated in the Phased Long-Term Control Plan originally prepared for MDNR in 2004, as described in Section 2.7 of this report. Table 3-10 denotes the forty-four separations already completed or in progress. CSO Outfall Numbers Receiving Water CSOs Separated, Outfalls Deleted from Permits Permitted Outfalls, Separation Completed or In-Progress Bissell Point Permit Mississippi River 056 055 Maline Creek 053, 060 Lemay Permit Mississippi River 145, 150, 155 Lower River Des Peres 156, 169 168 Middle River Des Peres 033, 034, 035, 055, 056, 060 046, 049, 062, 177 Upper River Des Peres 065, 097, 098 Deer Creek 107, 108, 161, 164, 165 Black Creek 109, 113 110, 112, 114, 115, 116, 160, 174, 175 Hampton Creek 132, 133 141 Gravois Creek 158, 162 157 Table 3-10 Combined Sewer Separations The estimated total capital cost of these sewer separation projects is $22 million in 2007 dollars. The estimated benefits of the sewer separations are summarized below. Parameter Units Estimated Annual Overflow Reduction Flow million gallons 100 BOD5 million lbs 0.029 TSS million lbs 0.248 Table 3-11 Benefits of Sewer Separations Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-26 February 2011 3.3 Receiving Waters As described above, combined sewers may discharge into the Mississippi River, Maline Creek, the River Des Peres, or its tributaries. A description of the receiving waters and number of outfalls is presented below. More detailed information on the classified stretches of these receiving waters is presented in Section 3.3.2 of this plan. During wet weather events, the CSOs from within the Bissell Point and Lemay service areas may discharge to: • Mississippi River (60 permitted CSOs) • River Des Peres – Lower and Middle (52 permitted CSOs) • River Des Peres – Upper (39 permitted CSOs) • Tributaries to the River Des Peres (42 permitted CSOs) • Maline Creek (4 permitted CSOs) • Gingras Creek (1 permitted CSO) • Gravois Creek (1 permitted CSO, recently separated and removed) The locations of these receiving waters and CSOs are shown in Figure 3-14. Figure 3-14 CSO Receiving Waters Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-27 February 2011 Upper River Des Peres Hanley Hills Branch at Melrose & Ferguson 3.3.1 Descriptions In addition to combined sewer overflows, these water bodies also receive pollutant loads from SSOs and storm water discharges. Descriptions of each of the water bodies are included below. 3.3.1.1 Mississippi River The Mississippi River at St. Louis receives significant point and nonpoint source loads from a 697,000 square mile drainage area, as well as local discharges from municipal, industrial, and agricultural wastewater treatment facilities located in St. Louis City and St. Louis County, Missouri, and Madison and St. Clair Counties, Illinois. The Mississippi River at St. Louis has a daily average flow of approximately 175,000 cubic feet per second. 3.3.1.2 River Des Peres – Lower and Middle The Lower River Des Peres starts below the confluence of Deer Creek and extends about six miles to the Mississippi River. The river channel has rip-rap slopes and a natural bottom downstream of Chippewa Street. Flow consists of a small base flow, and large volumes of intermittent storm drainage from runoff, storm sewers, and combined sewers. The Lower River Des Peres is subject to backwater from the Mississippi River. The Middle River Des Peres extends approximately seven and one half miles from the intersection of Dartmouth and Harvard Streets in University City to the City-County boundary at the confluence with Deer Creek. The upper four and one half mile reach has been enclosed and is a combined sewer. The lower three mile reach, beginning near the Macklind Pump Station, is an open channel with a concrete base and concrete or rip-rap slopes. Flow is intermittent, consisting entirely of storm drainage from the Upper River Des Peres and combined sewers. Rock Creek is a tributary to the Lower River Des Peres. The entire creek, except for the lower one half mile reach, has been enclosed and serves as a combined sewer. The open lower reach is part earthen channel and part improved channel with areas of rip-rap bottom and sides. Flow results entirely from wet weather overflows of the Rock Creek Sewer and another small combined sewer. 3.3.1.3 River Des Peres – Upper The Upper River Des Peres extends approximately six miles in the Lemay service area from near Ashby and Warson Roads to the location described above where it has been enclosed. The Upper River Des Peres earthen channel includes a few improved concrete sections. Flow is intermittent, and consists of storm drainage from separate storm sewers and overflows from combined sewers. Mississippi River near McKinley Bridge River Des Peres near mouth Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-28 February 2011 Maline Creek upstream from Riverview Drive 3.3.1.4 River Des Peres - Tributaries to the River Des Peres (Hampton, Claytonia, Black, and Deer Creeks) Hampton and Claytonia Creeks are intermittent streams with some concrete sections. Hampton Creek discharges into Black Creek just west of the intersection of Manchester and Hanley Roads. Claytonia Creek discharges into Hampton Creek near Alicia Avenue. In both streams, trunk sewers convey wastewater toward the stream bed and an interceptor sewer, located under the creek, normally intercepts flow. Combined sewage flow in excess of interceptor capacity is discharged to the creeks. Deer Creek extends approximately 10 miles from the city of Creve Coeur to the River Des Peres. The Deer Creek and tributary channels are largely earthen, though some improved concrete sections are present (e.g., Hampton Creek). Flow is intermittent, and consists of storm drainage from runoff, storm sewers, and combined sewers. Black Creek is an intermittent stream that discharges to Deer Creek southwest of the intersection of Manchester and Hanley Roads. As with Hampton and Claytonia Creeks, trunk sewers convey wastewater toward the stream bed and an interceptor sewer, located under the creek, normally intercepts flow. Wet weather flow from storm drainage and combined sewers in excess of interceptor capacity discharges to the creek. 3.3.1.5 Maline Creek Maline Creek extends approximately seven miles from east of Lambert-St. Louis International Airport through the Bissell Point service area to the Mississippi River. The earthen channel includes some improved sections in the lower classified reaches that have concrete bottoms and side slopes. Flow in the upper reaches is intermittent, and consists mostly of storm runoff and drainage from storm sewers. Four known combined sewer outfalls drain to the lower reaches of the creek, which are also subject to backwater from the Mississippi River. 3.3.1.6 Gingras Creek Gingras Creek is an intermittent stream that extends approximately one mile from Bissell Point Outfall 059 (near I-70 and San Diego Court) to the Baden Combined Sewer (near the intersection of Lucas and Hunt Road and Sand Piper Drive). When flow is present, it is primarily from storm runoff, drainage from storm sewers and the CSO. 3.3.1.7 Gravois Creek Gravois Creek extends 11 miles from South St. Louis County to the River Des Peres, and is classified as a metropolitan no-discharge stream. The lower reaches of the earthen channel maintain permanent flow. In the upper reaches, flow is intermittent, and consists primarily of storm drainage from runoff, separate storm sewers, and one small combined sewer overflow (recently separated and eliminated). 3.3.2 Water Quality Standards One of the primary goals of CSO control is maintenance of designated beneficial water uses of receiving streams through attainment of appropriate water quality goals. Stream classifications and use designations for the combined portions of the Bissell Point and Lemay service areas are taken from Title 10 of the Missouri Code of State Regulations, Division 20, Chapter 7.031, Water Quality Standards, July 31, 2008 and the revisions approved by the Missouri Clean Water Commission on July 1, 2009. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-29 February 2011 3.3.2.1 Classifications and Designated Uses of Receiving Waters Classifications and designated beneficial uses for water bodies within the combined sewer service areas are outlined in Table 3-12. Use classifications exist to protect agricultural uses, aquatic life and human health, recreation, and water supply. The designated use is the use specified for the water body in the water quality standards (WQS) whether or not it is being attained. All classified water bodies in Missouri are designated for whole body contact recreation unless otherwise supported by a use attainability analysis (UAA). MDNR has established two designated use categories of primary contact recreation: 1. Whole Body Contact Class A (WBC-A) “applies to those water segments that have been established by the property owner as public swimming areas allowing full and free access by the public for swimming purposes and waters with existing whole body contact recreational use(s).” 2. Whole Body Contact Class B (WBC-B) for all waters designated for whole body contact use but not covered in WBC-A. There is also a secondary contact recreation (SCR) classification, which includes limited contact incidental to shoreline activities and activities where users do not swim or float in the water. For aquatic life uses, water bodies within the combined service area are classified as Class P or C streams and can also be designated as metropolitan no discharge streams. The Mississippi River, the lower portions of Gravois, Deer and Black Creeks, and the Lower River Des Peres are Class P streams. Class P indicates that streams maintain permanent flow even in drought periods and criteria exist to protect aquatic life. The lower portion of Maline Creek and the middle portion of Gravois Creek are Class C streams. Flow in Class C streams may cease in dry periods; however, the stream maintains permanent pools that may support aquatic life and therefore aquatic life criteria are applicable. Gravois Creek is classified as a metropolitan no discharge stream and discharges (other than non- contaminated stormwater flows) are prohibited unless specifically authorized in the water quality standards. Several of the streams in the combined sewer service areas are unclassified. These include the Middle and Upper River Des Peres; Hampton, Rock and Claytonia Creeks; Gingras Creek; and the upper reaches of Gravois, Black, Deer and Maline Creeks. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-30 February 2011 Classification Designated Beneficial Uses Receiving Water Unclassified P- Permanent Flow C - Permanent Pools Metropolitan No Discharge Stream Irrigation Livestock & Wildlife Watering Warm Water Aquatic Life & Human Health-Fish Consumption Whole Body Contact (A or B) Secondary Contact Recreation Drinking Water Supply Industrial Mississippi River (Des Moines River to L&D 27) X X X A X X X Mississippi River (L&D 27 to Cuivre River) X X X A X X X Mississippi River (Cuivre River to Missouri River) X X X A X X X Mississippi River (Missouri R. to N. Riverfront Park) X X X X B X X X Mississippi River (N. Riverfront Park to Meramec R.) X X X X X X X Mississippi River (Meramec R. to Kaskaskia River) X X X B X X X Mississippi River (Kaskaskia River to Ohio River) X X X X B X X X Mississippi River (Ohio River to State Line) X X X X B X X X Maline Creek (upper reaches) X Maline Creek (next 0.6 miles) X X X B X Maline Creek (lower 0.5 mile) X X X X Gingras Creek X Upper River des Peres X Middle River des Peres X Lower River Des Peres X X X X Black Creek (upper reaches) X Black Creek (lower 1.6 miles) X X X B X Deer Creek (upper reaches) X Deer Creek (lower 1.6 miles) X X X B X Other tributaries to Lower River Des Peres (Hampton, Claytonia, Rock Creeks) X Gravois Creek (upper reaches) X X Gravois Creek (next 6 miles) X X X X B Gravois Creek (lower 2.3 miles) X X X X B Table 3-12 Stream Classifications and Designated Uses As part of the water quality standards review by the CSO Control Policy, a UAA, which is defined as “a structured scientific assessment of the chemical, biological, and economic condition in a waterway” (EPA, 2001), may be used to determine if currently enforceable WQS can be achieved and if justification for reclassification exists. Missouri established a protocol for conducting recreational UAAs (MDNR 2004). MSD submitted three UAA reports to the MDNR on July 14, 2005 in accordance with this protocol. These are the July 2005 reports titled Mississippi River Whole Body Contact Recreation Use Attainability Analysis, River Des Peres Whole Body Contact Recreation Use Attainability Analysis, and Maline Creek Whole Body Contact Recreation Use Attainability Analysis. The 2005 Mississippi River UAA was updated with substantially more data, and the update was submitted on October 11, 2007. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-31 February 2011 The Mississippi River UAA report concluded that Whole Body Contact Recreation (WBCR) is not an existing use on the Mississippi River between the Missouri Department of Conservation North Riverfront Park to the Meramec River, based on numerous interviews and visual observations. The study also concluded that WBCR cannot be attained because of hydrologic modifications (channelization) that result in high velocities, and a high volume of barge traffic which make WBCR extremely unsafe if not impossible. On December 30, 2005, MDNR proposed SCR for 195 miles of the river. On December 12, 2008 EPA disapproved 165 of these miles – the segment below St. Louis. On July 1, 2009 the Missouri Clean Water Commission approved proceeding with a final rule to add WBCR back to these 165 miles of river. The River Des Peres UAA report concluded that WBCR is not an existing use on the River Des Peres from Morgan Ford Road to the confluence with the Mississippi River based on numerous interviews and visual observations. The study also concluded that WBCR cannot be attained because of natural, ephemeral, intermittent, or low-flow conditions that result in water that is not deep enough to support WBCR. On October 31, 2006 EPA approved no recreation for 1.5 miles of the river, but requested SCR for 1.0 miles of the river. On July 1, 2009 the Missouri Clean Water Commission approved proceeding with a final rule to add SCR to 6.3 miles of the river (from the Mississippi River to Deer Creek). The Maline Creek UAA report concluded that WBCR is not an existing use based on numerous interviews and visual observations. The study also concluded that WBCR cannot be attained because of natural, ephemeral, intermittent, or low-flow conditions that result in water that is not deep enough to support WBCR. On October 31, 2006 EPA disapproved this determination. On July 1, 2009 the Missouri Clean Water Commission approved proceeding with a final rule to add SCR to the lower 0.5 miles of the stream and WBCR Class B to the next 0.6 miles extending to Bellefontaine Road. In addition, MDNR completed two UAA reports on November 4, 2008. These reports are titled Use Attainability Analysis for WBID 3825 Black Creek and Use Attainability Analysis for WBID 3826 Deer Creek. On July 1, 2009 the Missouri Clean Water Commission approved proceeding with a final rule to add WBCR to 1.6 miles of Deer Creek (from River Des Peres to Black Creek), and WBCR to 1.6 miles of Black Creek (from Deer Creek upstream). As with the other water bodies, a final approval of the new water quality standards has yet to be given by EPA. 3.3.2.2 Water Quality Criteria Water quality criteria represent the chemical, physical, and biological properties of water that are necessary to protect beneficial water uses. These criteria include both “general criteria” applicable to all receiving streams regardless of their classification, and “specific criteria” applicable to classified waters. Specific criteria designed to protect against acute toxicity also apply to unclassified waters if those waters support aquatic life on an intermittent basis. The specific criteria in the Missouri Department of Natural Resources (MDNR) water quality standards apply to classified waters and the acute criteria apply to unclassified waters that support aquatic life. Limits for each listed pollutant are specified for the different designated water uses. The water use with the most stringent numerical value determines the applicable water quality criteria for a particular classified receiving stream. The specific criteria for protection of aquatic life can also be a function of chronic and acute toxicity requirements, characteristics of the receiving water (e.g., hardness, temperature and pH), and water use designation. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-32 February 2011 Missouri’s water quality standards include bacteria criteria associated with certain recreational uses. These criteria are to be applied as a geometric mean of values collected during the recreation season (April 1 to October 31). Parameter Notes Units Acute Criteria Chronic Criteria Ammonia nitrogen as N pH and temperature dependent mg N/L 0.6 – 56.6 0.1 – 6.9 Dissolved oxygen Minimum daily average mg/L 5.0 Table 3-13 Water Quality Criteria for Ammonia and Dissolved Oxygen Geometric Mean Criterion Designated Use E. coli (#/100 mL) WBC-A, Public Swimming Area 126 WBC-B, Whole Body Contact Recreation 206 Secondary Contact Recreation 1,134 Table 3-14 Water Quality Criteria for E. coli 3.3.3 Existing Water Quality The Water Quality Study Report (LimnoTech, 2006) provides comparisons of water quality data collected for the CSO programs with numeric criteria in MDNR’s water quality standards. The report concluded that, for the tributaries receiving CSOs, bacteria and dissolved oxygen are parameters of concern, and ammonia is a potential parameter of concern, based on occasional exceedances of chronic criteria in the past. For the Mississippi River, neither bacteria, dissolved oxygen nor ammonia were parameters of concern. The report presented statistical summaries of these parameters for each receiving water in the form of box and whisker plots (with accompanying tables); these have been updated for this report, using data collected in the interim. 3.3.3.1 Ammonia Missouri’s water quality standards for ammonia are based on total ammonia, and depend on the pH and temperature of the receiving waters. MSD has conducted receiving water studies for CSO control planning since 1995. Findings from these studies have indicated that acute toxicity concentration criteria for ammonia are not exceeded, whereas chronic toxicity concentration criteria are exceeded for a short time period during some overflow events in the Lower River Des Peres. Water quality returns to levels below chronic standards shortly after the wet weather events. Measurements of ammonia for the River Des Peres wet weather events showed that ammonia levels returned to levels below detection after the first day of each of the two wet weather events that were monitored (Sverdrup, 1999). These data were collected in 1997-1998 prior to the operation of the Lemay Overflow Regulation System, which has substantially reduced CSO discharges. Subsequent data showed that levels collected during wet weather in the River Des Peres did not approach the applicable chronic criteria. The one sample that was greater than the chronic criterion was collected during dry weather (October 4, 2005). It should be noted that chronic criteria are established to protect aquatic life from long-term exposure effects from continuous discharges, and that, in general, samples should be collected over a three or four-day period at a minimum for comparison to the 30-day average chronic criteria; that is, an individual measurement that exceeds the chronic criterion should not be taken as a violation. Figures 3-15 through 3-17 present box and whisker plots and summary statistics of the total ammonia concentrations measured at each of the monitored locations. In the plots, the box represents the 25th and 75th percentiles of the observations, the square in the box represents the median concentration, and the Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-33 February 2011 whiskers represent the minimum and maximum concentrations. Many observations were less than the analytical detection limit (generally 0.7 mg/L for MSD and 0.05 mg/L for USGS). 07005000 Bellefontaine Maline_1 Mouth Engel Kingstead 07010022 U City Purdue Site 8 Vernon Count 49 12 11 42 14 Max 1.5 0.70 0.70 9.9 1.1 75th 0.20 0.70 0.70 0.83 0.70 Median 0.12 0.70 0.70 0.39 0.60 25th 0.07 0.70 0.70 0.19 0.60 Min 0.01 0.60 0.60 0.01 0.60 Maline Creek Upper River Des Peres Figure 3-15 Total Ammonia Levels in Maline Creek and the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-34 February 2011 Site 7 Macklind Site 6 Arsenal Black_1 Manchester Deer_3 Br. Ind. Ct. Site 5 Big Bend Deer_1 St. Louis Count 12 13 11 11 13 11 Max 1.7 1.1 2.2 0.7 1.1 0.8 75th 0.70 0.70 0.70 0.70 0.70 0.70 Median 0.60 0.70 0.70 0.70 0.60 0.70 25th 0.60 0.60 0.65 0.65 0.60 0.65 Min 0.60 0.60 0.60 0.60 0.60 0.60 Middle River Des Peres Tributaries Figure 3-16 Total Ammonia Levels in the Middle River Des Peres and Tributaries Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-35 February 2011 Gravois Ck Site 4 Watson Site 3 Gravois Rd 07010097 Morganford RDP-4 Morganford RDP-2 Sharp RDP-3 I-55 RDP-1 Alabama Site 1 Broadway Site 2 Weber Count 13 13 13 17 14 14 5 28 18 Max 1.1 1.1 2.1 3.0 1.0 1.0 0.6 1.0 0.7 75th 0.7 0.7 0.8 1.0 0.7 0.7 0.5 0.7 0.7 Median 0.6 0.6 0.3 0.3 0.3 0.4 0.3 0.6 0.6 25th 0.60 0.60 0.04 0.2 0.3 0.3 0.2 0.6 0.6 Min 0.60 0.60 0.02 0.2 0.2 0.2 0.2 0.3 0.6 Lower River Des Peres Figure 3-17 Total Ammonia Levels in the Lower River Des Peres and Gravois Creek 3.3.3.2 Dissolved Oxygen MSD conducted a comparison for all receiving waters in response to an EPA request to provide information on water quality monitoring to determine the impact that CSO discharges are having on dissolved oxygen levels in the receiving waters and their respective tributaries. There were no violations of the criteria and concentrations were generally well above 5.0 mg/L in the Mississippi River, as shown in Figure 3-18. Therefore, dissolved oxygen data for the Mississippi River suggest that dissolved oxygen should not be a parameter of concern for this water body. Concentrations in Maline Creek, both upstream and downstream of the CSOs, were occasionally below 5.0 mg/L. There were also a few observations in the Upper River Des Peres and the Middle River Des Peres that were less than 5.0 mg/L. Concentrations in the unclassified tributaries of the River Des Peres, the Lower River Des Peres, and Gravois Creek were also occasionally below 5.0 mg/L. These data are summarized in Figures 3-19 through 3-21. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-36 February 2011 Incidences of low dissolved oxygen were separated by base and storm flow conditions, as well as by dry and wet weather designations. The fact that the incidences occurred under all flow conditions suggested that sediment oxygen demand was not the sole contributing cause; hydrologic modifications and larger watershed issues also play a role in low dissolved oxygen conditions. Mississippi River 05587455 Below Grafton 07005500 Above St. Louis 07010000 at St. Louis 07010220 Oakville 07019370 Kimmswick Count 166 37 39 38 38 Max 20.1 12.3 12.8 11.7 12.6 75th 12.7 9.0 9.0 8.9 8.9 Median 9.8 7.9 8.0 7.8 7.8 25th 7.9 6.7 6.9 6.6 6.7 Min 4.5 4.9 4.8 5.0 5.4 Figure 3-18 Dissolved Oxygen Levels in the Mississippi River Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-37 February 2011 07005000 Bellefontaine Maline_2 St. Cyr Maline_1 Mouth Engel Kingstead 07010022 U City Purdue Site 8 Vernon Count 85 4 43 38 81 21 Max 15.9 6.7 15.0 11.9 20.0 11.9 75th 10.3 6.0 10.8 10.0 11.2 8.1 Median 7.5 5.6 8.3 8.0 8.6 6.6 25th 6.1 5.0 6.2 6.1 6.1 6.0 Min 2.6 3.9 4.1 4.0 0.4 4.7 Maline Creek Upper River Des Peres Figure 3-19 Dissolved Oxygen Levels in Maline Creek and the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-38 February 2011 Middle River Des Peres Tributaries Site 7 Macklind Site 6 Arsenal Black_1 Manchester Deer_3 Br. Ind. Ct. Site 5 Big Bend Deer_1 St. Louis Count 19 20 40 40 20 40 Max 10.1 10.6 12.8 13.0 11.0 13.6 75th 8.3 8.5 9.6 10.4 7.9 10.5 Median 7.4 6.8 6.8 7.3 7.0 8.0 25th 6.2 5.7 5.7 5.8 5.9 6.3 Min 5.2 4.8 3.2 3.0 4.5 2.8 Figure 3-20 Dissolved Oxygen Levels in the Middle River Des Peres and Tributaries Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-39 February 2011 Lower River Des Peres Gravois Ck Site 4 Watson Site 3 Gravois Rd 07010097 Morganford RDP-4 Morganford Site 1 Broadway Site 2 Weber Count 20 18 47 1 23 25 Max 10.3 10.4 18.9 5.3 10.0 11.4 75th 7.8 7.9 13.1 5.3 8.1 7.9 Median 7.1 7.0 9.8 5.3 7.0 7.1 25th 6.1 5.8 7.7 5.3 5.5 6.4 Min 4.3 3.4 1.6 5.3 4.6 4.9 Figure 3-21 Dissolved Oxygen Levels in the Lower River Des Peres and Gravois Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-40 February 2011 3.3.3.3 Indicator Bacteria (E. coli) Revisions to the water quality standards include bacteria criteria. MSD is therefore addressing bacteria as a pollutant of concern in the revised LTCP as applicable. Missouri has adopted recreational uses and geometric mean bacteria criteria. The water quality standards contained criteria for both fecal coliform and E. coli bacteria until December 31, 2008; subsequently only the E. coli criteria apply. Only E. coli data are discussed here, whereas the water quality study includes analyses of both bacteria measurements. Based on a data comparison MSD conducted for EPA, it was found that bacteria levels in the Mississippi River near St. Louis are orders of magnitude less than bacteria in the other receiving waters. E. coli levels in the Mississippi River below Grafton (upstream of the CSOs) met the Class A criterion from 1999 to 2008, but exceeded this criterion for the 1998 recreation season. E. coli levels in the Mississippi River near and downstream of St. Louis did not exceed the geometric mean criterion for Class B recreation waters during 2006 and 2007; some stations exceeded this criterion in 2005, and all stations exceeded the criterion in 2008. The SCR criterion was met at all stations for the years presented above. The Mississippi River data are summarized in Figure 3-22. Figures 3-23 through 3-25 summarize the E. coli data for the other CSO receiving waters. Levels in Maline Creek and River Des Peres are high throughout the study area during wet weather, including areas that are upstream of the CSO discharges. Levels in the Lower River Des Peres at Morgan Ford Road did not exceed the E. coli geometric mean criterion for SCR from 2005 through 2008. Levels in Maline Creek at Bellefontaine (upstream of the CSOs) exceeded the applicable Class B geometric mean criteria for E. coli from 2005 through 2008. In the lower reach of Maline Creek, where the SCR criterion is applicable, sufficient data were not available to calculate geometric means for individual recreation seasons; the upstream site met this criterion in 2006 and 2007, but not in 2005 and 2008. Recreation season geometric means in the Upper River Des Peres, which is unclassified, were greater than the E. coli criterion for SCR from 2005 through 2008. Based on data through 2005, the 2006 water quality study report recommended that receiving water modeling of bacteria in the Mississippi River to evaluate CSO impacts was unnecessary. Modeling was recommended, however, for both Maline Creek and the River Des Peres to evaluate CSO impacts on water quality, and to support a watershed wide approach that addresses CSO, SSO, stormwater, and other sources. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-41 February 2011 Mississippi River 05587455 Below Grafton 07005500 Above St. Louis 07010000 at St. Louis 07010220 Oakville 07019370 Kimmswick Count 149 36 37 36 36 Max 1,600 1,100 880 1,600 1,100 75th 110 173 240 548 403 Median 30 50 100 260 255 25th 1027408298 Min 1 4 12 10 20 Figure 3-22 E. coli Levels in the Mississippi River Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-42 February 2011 Maline Creek Upper River Des Peres 07005000 Bellefontaine Maline_2 St. Cyr Engel Kingstead 07010022 U City Purdue Site 8 Vernon Count 6427275814 Max 280,000 37,000 1,400 510,000 21,000 75th 5,350 795 300 16,000 4,725 Median 1,450 200 100 3,350 2,100 25th 530 100 100 1,325 1,175 Min 103027 4200 Figure 3-23 E. coli Levels in Maline Creek and the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-43 February 2011 Middle River Des Peres Tributaries Site 7 Macklind Site 6 Arsenal Black_1 Manchester Deer_3 Br. Ind. Ct. Site 5 Big Bend Deer_1 St. Louis Count 13 14 26 26 14 26 Max 100,000 120,000 10,000 8,000 8,200 6,400 75th 27,000 17,000 525 283 5,950 300 Median 9,500 4,600 185 100 3,050 100 25th 3,400 1,500 100 100 898 100 Min 300 54 18 9 100 10 Figure 3-24 E. coli Levels in the Middle River Des Peres and Tributaries Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-44 February 2011 Gravois Ck Site 4 Watson Site 3 Gravois Rd 07010097 Morganford Site 1 Broadway Site 2 Weber Count 14 12 29 13 14 Max 28,000 22,000 94,000 15,000 6,800 75th 5,425 7,700 3,700 8,200 2,675 Median 3,550 4,300 600 5,600 2,250 25th 2,150 1,450 52 900 1,300 Min 10 100 4 100 100 Lower River Des Peres Figure 3-25 E. coli Levels in the Lower River Des Peres and Gravois Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-45 February 2011 3.3.4 Flow Regime The flow regime in several of the streams and rivers in the combined sewer service area has been shown to impact water quality conditions in those water bodies. For instance, flow in the Lower River Des Peres is regularly subject to Mississippi River backwater as far upstream as Morgan Ford Road, and farther at times. Similarly, the lower reaches of Maline Creek can also be influenced by Mississippi River backwater. Section 6 of this LTCP report further discusses the estimated impacts of backwater conditions on receiving water quality. 3.3.5 Sensitive Waters 3.3.5.1 CSO Policy Requirements The CSO Control Policy “expects a permittee’s long-term CSO control plan to give the highest priority to controlling overflows to sensitive areas.” Sensitive areas are to be determined by the NPDES Permitting Authority in coordination with State and Federal Agencies, as appropriate. The Policy and EPA guidance (USEPA, 1995) indicates that sensitive areas may include: • Outstanding National Resources Waters (ONRW) • National Marine Sanctuaries (NMS) • Shellfish beds • Waters with primary contact recreation, such as bathing beaches • Waters with threatened or endangered species and their habitat, and • Public drinking water intakes and their designated protected areas. The CSO Control Policy states that if sensitive areas are present and impacted, the LTCP should include provisions to: • Prohibit new or significantly increased overflows, • Eliminate or relocate overflows where possible, • Treat overflows where necessary, and • Where elimination or treatment is not achievable, reassess impacts each permit cycle. 3.3.5.2 Findings The six types of sensitive areas were examined separately for CSO-impacted receiving waters. No Outstanding National Resource Waters (ONRWs) have been designated in the CSO receiving waters in or around St. Louis (MDNR, 2008). No National Marine Sanctuaries (NMS) have been designated within the CSO area (NOAA, 2007). There are no known commercial shellfish beds nor is shellfish harvest for consumption by private individuals known to occur. Therefore, ONRW, NMS and shellfishing designations are not relevant for the identification of sensitive waters for MSD’s LTCP. The other three sensitive areas designations were assessed further. 3.3.5.2.1 Public drinking water intakes and their designated protection areas Information on public drinking water intakes located within MSD CSO receiving waters was provided by both the MDNR and the Illinois EPA (IEPA). The MDNR indicated that the nearest drinking water intake on the Mississippi River downstream of St. Louis is the intake for the City of Cape Girardeau, Missouri. The IEPA provided the location of one drinking water intake on the Mississippi River near St. Louis. This intake is owned by the Illinois American Water Company (IAWC) and serves the City of East St. Louis, Illinois. The next drinking water intake in Illinois is approximately 90 miles downstream at Chester. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-46 February 2011 Cape Girardeau, Missouri, is approximately 136 miles downstream of St. Louis. At this drinking water intake, all incoming water is treated to remove bacteria, turbidity and toxic constituents. The City of Cape Girardeau intends to phase out their use of the Mississippi River as a drinking water source, and the project is ongoing (Macy, 2009). The MDNR defines priority areas for source water protection for large watersheds as a five-mile radius upstream of the intake (MDNR, 2000). Therefore, MSD CSO discharges should not be considered as potentially impacting drinking water supplies for Missouri. The IAWC East St. Louis drinking water intake is located approximately one mile upstream from the Poplar Street Bridge on the Mississippi River. At this drinking water intake, all incoming water is treated to remove bacteria, turbidity and other toxic constituents. The IEPA has defined the Mississippi River as a Zone 1 Buffer for drinking water from a quarter mile buffer on either side of the river, extending from a quarter mile downstream of this drinking water intake to twenty-five miles upstream (or the five hour time of travel; IEPA 2001). Maline Creek, Gingras Creek, and the Mississippi River receive CSO discharges from MSD’s collection system and are located within the Zone 1 Buffer for the IAWC East St. Louis drinking water intake. MSD’s CSO discharges should not, however, be considered as impacting this drinking water supply for two reasons: the unlikelihood of CSO flows reaching the drinking water intake and the insignificant contribution of pollutants to the intake withdrawal should CSO flows actually reach the intake. Given the hydrological conditions that may affect mixing from the Missouri side to the Illinois side of the Mississippi River, MSD conducted an analysis to estimate the likelihood of MSD’s CSO discharges impacting the IAWC East St. Louis drinking water intake on the opposite bank of the Mississippi River. Fischer et al. (1979) provides equations for estimating the downstream distance required to achieve complete mixing from side discharges to a river. This assumption is reasonable for CSOs discharging to the Mississippi River because the initial momentum of the discharges is dominated by the river velocity over a relatively small distance. The procedure neglects any initial momentum or buoyancy of the discharge and assumes that mixing is due to the turbulence of the river alone, which is a realistic approximation given the significant flow in the Mississippi River. Turbulence in the equations is characterized by a transverse mixing coefficient that is determined by dimensional analysis from the shear velocity and depth of flow in the river. Experiments and measurements confirm the general form of the relationship although a range of values may be observed. This range is reflected in the results presented here. Figure 3-26 presents the downstream mixing distance as a function of river discharge, with discharge expressed as frequency of occurrence (based on USGS gage records from 1933 through 2004). The solid line uses Fischer et al.’s (1979) transverse mixing coefficient directly whereas the upper and lower dashed lines represent minus 50 % and plus 50 % mixing coefficient, respectively, to reflect the range of experimental values that Fischer, et al. observed in developing the mixing coefficient. A higher value of transverse mixing means that complete mixing is accomplished in a shorter distance. CSO flows into the Mississippi River can vary widely. In 2006, the highest peak instantaneous CSO flow rate was 2,300 million gallons per day (Jacobs, 2006). This flow is 1.64% of the average April to October Mississippi River discharge of 217,000 cubic feet per second. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-47 February 2011 Figure 3-26 Theoretical Distance to Complete Mix for Side Discharges to the Mississippi River near St. Louis, MO Figure 3-15 indicates that at a median (50 %) discharge, point sources may require from 32 to 100 miles to become completely mixed across the river. Maline Creek enters the Mississippi River approximately seven miles upstream from the IAWC East St. Louis drinking water intake. Considering only the lower line in Figure 3-15, which is based on higher estimates of transverse mixing to potentially better account for river bends, wing dams and other features known to enhance mixing, at least ten miles of downstream travel would be required for side discharges to mix across the river even at very high flows (> 95th percentile). It therefore appears unlikely that MSD CSO discharges from Maline Creek or downstream would mix across the Mississippi River and affect the IAWC East St. Louis drinking water intake. Nutrient loading and other effects of the extensive agricultural activities within the Mississippi River basin are cited as the major concerns for nonpoint source pollution of the IAWC East St. Louis drinking water intake (IEPA, 2001). For this intake, “other nonpoint sources” of pollution, “urban runoff” and bacterial pollutants are also listed as concerns by IEPA (2001). CSOs include urban runoff. At the IAWC East St. Louis drinking water intake, however, water suppliers do not routinely see high (that is, >100s of colonies per 100 mL) bacteria levels (Boyd, 2007). High bacteria levels in the incoming water are generally associated with large upstream runoff events and corresponding high river flows and high turbidity (Boyd, 2007). There are also several regular sources of bacteria to the Mississippi River. Undisinfected effluent from wastewater treatment plants (WWTPs) upstream of the IAWC East St. Louis drinking water intake include: Coldwater Creek and Missouri River in Missouri and Wood River, Edwardsville, and Granite City in Illinois. IAWC provides treatment to address these sources and therefore would also provide adequate treatment in the unlikely event that a CSO discharge did impact the East St. Louis intake. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-48 February 2011 3.3.5.2.2 Waters with primary contact recreation As stated above, all classified water bodies in Missouri are designated for whole body contact recreation unless otherwise supported by a UAA, which is discussed further above. The following summarizes the designated recreational uses as previously discussed in Section 3.3.2: • The Mississippi River is designated as WBC-A and WBC-B for river segments upstream of MSD’s CSOs. The 165-mile segment below St. Louis is also designated as WBC-B. • US EPA determined that the lower 1.0 mile of Maline Creek is sufficient to support WBCR and therefore disapproved MDNR’s designation of this reach as not supporting recreational uses. The Missouri Clean Water Commission (MCWC) approved proceeding with a final rule to add SCR to the lower 0.5 miles and WBC-B to the next 0.6 miles of the creek, but this still needs EPA approval. • The MCWC approved proceeding with a final rule to add SCR to the 6.3 miles of the River Des Peres from the Mississippi River to Deer Creek. EPA will need to approve this. • The MCWC approved proceeding with a final rule to add WBCR to 1.6 miles of both Deer and Black Creeks. EPA will need to approve both of these designations. • Gingras Creek, the Upper and Middle River Des Peres, Hampton, and Claytonia Creeks are unclassified and therefore not designated to support recreational uses. There are no known designated public or private swimming areas within MSD’s CSO service area. There are also no plans for construction of public swimming facilities along these waterways. The absence of public swimming areas and minimal use of the waters for swimming does not support considering the CSO-impacted waters as sensitive areas. There is, however, no clear guideline for determination of areas as sensitive for primary contact recreation. 3.3.5.2.3 Waters with threatened or endangered species and their habitat In order to determine the latest listings of state and federally threatened or endangered species and their habitat, both the Missouri Department of Conservation (MDC) and the United States Fish and Wildlife Service (USFWS) were contacted in March 2007. Two species were identified within the MSD’s CSO area (MDC, 2007). The MDC identified the state endangered peregrine falcon (Falco peregrinus) within MSD’s service area. Major threats to peregrine falcons in Missouri include human disturbance of nesting birds, alteration of nesting habitat and continued use of environmental contaminants (MDC, 2000a). Nesting areas are of primary concern for this species, and peregrine falcons typically nest on bluffs. Thus, peregrine falcons are unlikely to be affected by CSOs. The USFWS identified one federally listed aquatic species in MSD’s CSO receiving waters, the pallid sturgeon (Scaphirhynchus albus). The pallid sturgeon was listed as an endangered species because of habitat alteration and the threat of hybridization with shovelnose sturgeon (S. platorynchus) (Federal Register 55 [September 6, 1990]: 36641-36647). The pallid sturgeon is present in the Missouri River and lower Mississippi River drainage basins (MDC, 2000b). Pallid sturgeons inhabit bottom areas of open channels with strong current, turbid waters, and a sandy substrate. They may also be found along sandbars and behind wing dikes. This species feeds on aquatic insects, crustaceans, mollusks and fish along the bottom of rivers (MDC, 2000b). The pallid sturgeon could be present in the Mississippi River in St. Louis County at any given time (Kuska, 2007). Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 3. EXISTING CONDITIONS Page 3-49 February 2011 The largest threats to the pallid sturgeon population are habitat modifications due to dam construction and operation, channelization, and navigation maintenance of major rivers (MDC, 2000b; Quist, 2004; Burton, 2007). Natural reproduction is impaired due to lack of suitable spawning habitat. Decline of the species has not been attributed to the presence of CSOs or other point source discharges. The connection between water quality and pallid sturgeon populations has been vaguely defined, and discussed in the context of heavy metals, PCBs, and pesticides as adversely affecting the population (Pallid Sturgeon Recovery Team, 1993). In a 2004 symposium of pallid sturgeon experts, recommendations were made that additional research be conducted to determine adverse impacts associated with pollutants (Quist, 2004). Pallid sturgeon and peregrine falcons are the only threatened and endangered species in the St. Louis area. The pallid sturgeon are endangered because of habitat modifications. Peregrine falcons are endangered because of disturbances to nesting habitat and continued use of environmental contaminants. CSOs are not known to adversely impact the pallid sturgeon or the peregrine falcon or their habitat. Therefore, there are no known impacts from CSOs on threatened or endangered species in MSD’s CSO area. This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-1 February 2011 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING 4.1 Introduction MSD’s characterization, monitoring, and modeling efforts establish the basis for evaluating occurrence, magnitude, volume, duration, and quality of CSOs and evaluating effectiveness of CSO controls. The objectives of these efforts are as follows: • To collect data on the frequency, quantity and quality of representative CSOs; • To collect, organize, and analyze hydraulic and hydrologic information; and, • To develop, calibrate and verify combined sewer system models that can be used together with water quality models in estimating the impacts of CSOs on receiving waters and supporting CSO planning efforts. This section of the report summarizes the characteristics of the combined sewer system and its discharges to receiving waters. Previous characterization, monitoring, and modeling efforts are discussed in Section 4.2. Characterization of the CSO and diversion structure physical attribute data is discussed in Section 4.3. The selection and description of representative flow and rainfall monitoring sites as well as CSO sampling activities are discussed in Section 4.4. The development of CSO event mean concentrations is discussed in Section 4.5. Finally, Section 4.6 summarizes the development, calibration, and verification of the hydraulic and hydrologic modeling efforts. 4.2 Previous Sewer System Characterization, Monitoring, and Modeling MSD has been collecting and analyzing basic data on its combined sewer system for decades. Reports documenting previous activities related to the development of this Plan are as follows: • Characterization, Monitoring, and Modeling Program (Sverdrup, 1996) • CSO Flow and Pollutant Characterization Report (Jacobs, 2006) • Draft Hydraulic Model Development Report (Jacobs, 2007) The Characterization, Monitoring, and Modeling Program Report, submitted in December 1996, is a comprehensive characterization, monitoring, and modeling report developed to support the original CSO LTCP submitted in 1999. The report utilized the best available information, monitoring and sampling technologies, and modeling software at the time of development. System wide mapping inherited from the various municipalities and sewerage agencies that once comprised what is now the District’s service area was compared against MSD-era as-built plans. Area-velocity flow meters and automated samplers were used to characterize combined flows in representative watersheds. This information formed the basis for the hydrologic and hydraulic models using EPA SWMM’s Runoff and Transport modules, respectively. The 2006 CSO Flow and Pollutant Characterization Report updated the 1996 report with digitized mapping, new surveys, significantly more flow monitoring locations, and better flow monitoring technologies. MSD maintains MicroStation files containing their infrastructure including labeled manholes, pipes, pump stations, force mains, and diversion structures. Also available electronically and as an overlay are parcel and contour information datasets and watershed delineations1. Additionally, in 2003 MSD initiated a multi-year, large-scale flow and rainfall monitoring program. As a part of the program, MSD used new metering technology to capture more representative velocities in their large diameter combined sewers. 1 MSD has since converted their system mapping to a GIS format. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-2 February 2011 The 2007 Draft Hydraulic Model Development Report summarizes the development, calibration, verification, and results of the hydrologic and hydraulic models. The original EPA SWMM modeling software was replaced with XP-SWMM software, which includes a graphical user interface. The interface permits a spatial representation of the model and its results that assists in quickly identifying locations of interest. The models were further enhanced by expanding to include all CSOs and recently constructed system improvements, incorporating recently collected data, utilizing more sophisticated hydraulic routing techniques and more refined watershed delineations compared to previous modeling efforts. 4.3 CSO and Diversion Structure Physical Attribute Data Verification Many of MSD’s outfall and diversion structures pre-date the formation of the District. Consequently, MSD desired to verify physical attribute data for a large number of its CSO outfalls and combined sewer system flow diversion structures. The characterization of the diversion and outfall structures is documented in CSO Flow and Pollutant Characterization Report prepared in 2006; the following paragraphs summarize MSD’s CSO and diversion structure physical attribute data verification program. Surveying and documentation were performed in 2004 and 2005 to verify record data at 188 of MSD’s CSO outfalls and 263 of MSD’s flow diversion structures. Multiple projects, and, consequently, multiple vendors, were utilized to complete the task. Generally, the following types of information were gathered: physical locations (northing and easting coordinates); numbers, sizes, shapes and configurations of inlet and outlet sewers; elevations of sewers and flow control elements such as dams, weirs, and gates; materials of construction; physical condition; and other relevant data. The data were recorded and documented for each surveyed outfall or diversion structure. The documentation consists of drawings, photographs, and condition reports. The outfalls (and related diversion structures) that were not surveyed had been identified for elimination in the near future or were generally small in size, ranging in diameter from 6 to 84-inch with a median diameter of 30 inches. An exception is the 9-ft diameter Catalan outfall (Lemay Outfall 147) that could not be surveyed due to river stage. Where necessary and possible, these outfalls and diversions were visually inspected and measured to verify the record data. 4.4 Monitoring Program MSD implemented a combined sewer monitoring program in 1995. The 15-month program collected flow and rainfall data on the combined sewer system and utilized wastewater samples to better understand its characteristics. This program is documented in the Characterization, Monitoring, and Modeling Program Report, submitted in 1996. A second flow and rainfall monitoring program was initiated in the combined sewer area in 2004 to collect additional information at more locations, with advanced technology, and at a more frequent time interval. This program is documented in CSO Flow and Pollutant Characterization Report, submitted in 2006. 4.4.1 Flow Monitoring Program Beginning in June 2004, temporary flow meters were installed to monitor flows for 29 combined sewer watersheds in the Bissell Point and Lemay service areas, as shown in Figure 4-1. The selected watersheds represent approximately 75% of the combined sewer area. Flows or levels were also monitored in the Skinker-McCausland Tunnel, the Bissell Point Interceptor Tunnel, and some combined sewer pockets outside of the primary combined sewer area. Table 4-1 summarizes the combined sewer system flow meters, including locations, sewer size, and receiving stream. The monitoring duration varied from site to site, but generally the flow meters were installed in June 2004 and removed in June 2005. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-3 February 2011 Figure 4-1 Flow Meter and Rain Gage Locations Monitoring Site No. Combined Sewer System Site Location Sewer Size (in) Receiving Stream 3505 Baden 7517 San Diego Ave 66 Gingras Creek 4200 Lindenwood Landsdowne Ave. at Wabash Ave. 72 Lower RDP 5501 Mackenzie 8100 Pointview Ln. 48 Lower RDP 5502 Fields 3833 Germania St. 78 Lower RDP 5503 Poepping-Tesson Carondelet Blvd. at Didier Rd. 48 Lower RDP 5504 Ellendale Canterbury Ave. at McCausland Ave.54 Lower RDP 12001 12002 Glaise Creek Germania St. at Primm Ave. 240 Lower RDP 4000 4001 Wherry Creek Wilmore Park 228 Lower RDP 4910 4911 Leone Crosby Carondelet Blvd. at Tesson Ct. 92 Lower RDP 17010 17011 17012 Maline/Watkins 9215 Riverview Dr. N/A Maline Creek 10014 10015 Tower Grove 4044 Park Ave. 108 Middle RDP 4700 McCausland 2779 Heritage Ave. 84 Middle RDP Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-4 February 2011 Monitoring Site No. Combined Sewer System Site Location Sewer Size (in) Receiving Stream 4701 3005 Harlem 6240 McKissock Ave. 48 Mississippi R. 3010 Harlem End of Taylor Ave. 324 Mississippi R. 7000 Mill Creek Chouteau Ave. at 6th St. 240 Mississippi R. 7901 Euclid 4164 W. Pine Blvd. 60 Mississippi R. 13601 Catalan End of Virginia Ave. N/A Mississippi R. 14500 Quincy S. Broadway at Quincy St. 52 Mississippi R. 16001 Chambers Chambers St. at North 1st St. 18 Mississippi R. 16002 Chambers 2000 Chambers St. 44 Mississippi R. 16102 Biddle 1206 Biddle St. 30 Mississippi R. 10009 10010 Tower Grove 4150 Park Ave. 180 Mississippi R. 14010 14011 Arsenal Arsenal St at 2nd St 90 Mississippi R. 14101 14102 Gasconade Osage St. at Illinois Ave. 120 Mississippi R. 14410 14411 Fillmore S. Broadway at Fillmore St. 96 Mississippi R. 14600 14601 Upton S. Broadway at Steins St. 48 Mississippi R. 16100 16101 Biddle Biddle St. at 2nd St. 144 Mississippi R. 17310 17311 Ferry N. Broadway at Ferry St. 78 Mississippi R. 3501 3502 Baden N. Broadway at Thrush Ave. 216 Mississippi R. 6010 6011 Palm / Branch Palm St. at 11th St. 180 Mississippi R. 1349 University City 851 N. Skinker Blvd. 78 N/A 1836 Claytonia 8000 Manchester Rd. 54 RDP Tributary 1831 Black Creek 20 York Dr. 21 RDP Tributary 1832 Black Creek 50 York Dr. 21 RDP Tributary 1833 Black Creek 1271 South Lay Rd. 21 RDP Tributary 1830 Black Creek 28 Ladue Manor 8 RDP Tributary 4500 4501 Maplewood 7140 Wellington Ct. 120 RDP Tributary 11010 Rock Creek Loughborough Ave. at Wanda Ct. 228 Rock Creek to Lower RDP 20050 Bissell – North 5300 Hall St. 78 N/A 20100 Bissell – North 6600 Hall St. 78 N/A 20200 Bissell – South 38 Washington Ave. 90 N/A Table 4-1 Flow Meter Summary The program utilized American Sigma 910 or 920 flow meters at most locations; however, MSD also used MGD Technologies (now Teledyne ISCO) ADFM flow meters on large diameter (e.g., greater than 96-inch diameter) sewers. The American Sigma meters utilize pressure transducers to record depth of flow measurements whereas the ADFM meters utilize Doppler ultrasonic technology. Both flow meter types use Doppler ultrasonic technology to record velocity measurements, but the ADFM meters take four velocity measurements at each time interval to develop a mean velocity value as opposed to the American Sigma flow meters, which take one measurement at each time interval. Consequently, the ADFM flow meters generally provided a more representative velocity reading, particularly in larger diameter sewers. Some sites were equipped with both types of flow meters to capture the full range of expected flows. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-5 February 2011 Measurements were typically recorded at five-minute intervals. Using these measurements and site characteristics (e.g., sewer cross-sectional shape) an estimated flow rate was developed. The flow meters were maintained and the collected data downloaded on a weekly basis for the duration of the monitoring period. 4.4.2 Rainfall Monitoring Program In support of the 2004-2005 flow monitoring program, temporary rainfall monitoring gages were deployed throughout the District’s service area. Twenty-five tipping-bucket type gages were located adjacent to or within the combined sewer area, as shown in Figure 4-1. The temporary gages were used in conjunction with the District’s permanent rainfall network of 21 tipping-bucket type gages, installed in support of the 1995-1996 monitoring program, also shown in Figure 4-1. The rain gage spacing represents an average areal coverage of approximately 3½ square miles per gage. This spacing is sufficient, considering the typical size of a thunderstorm cell (median size of approximately 40 square miles). The total number of tips in a five-minute interval is recorded by each gage. This information is then used to determine the durations, intensities, and total rainfall for the storm events occurring during the flow monitoring period. The gages were maintained and the collected data downloaded on a weekly basis for the duration of the temporary flow monitoring period. MSD also contracted with a radar rainfall monitoring vendor in 2004 to provide gage-adjusted radar rainfall (GARR) data, which had a spatial resolution of 1 km per pixel and a time resolution of five minutes. Additionally, the National Weather Service (NWS) maintains a fixed rain gage at Lambert- St. Louis International Airport. The GARR and NWS data were collected to supplement the temporary, fixed rain gage data. 4.4.3 Wastewater Sampling Wastewater quality monitoring was performed over a 3-month period at eleven monitoring locations, as shown in Figure 4-2 and summarized in Table 4-2. Sampling began in March 1996 using automatic, programmable American Sigma Streamline Model 800 samplers. Except as noted in Section 4.5, the sampling data from this period are considered to be largely representative of current conditions due to minimal changes in land use and collection system configuration that have since occurred. The samplers were programmed to collect 24 discrete samples for each monitored event on a timed- interval basis, which was determined based on the physical characteristics of the combined sewer system that would affect the typical duration of runoff from a storm event. Sampling intervals were set such that samples were taken more frequently at the beginning of a storm, to allow for characterizing the “first flush.” The sampling process was triggered based on readings from its associated flow meter. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-6 February 2011 Figure 4-2 Wastewater Monitoring Locations Site ID Subwatershed Sampler Location Receiving Stream BP-1 Riverview PCRS south of discharge channel Maline Creek BP-2 Ferry 17D1-231C Mississippi River BP-3 Branch 18D1-378C Mississippi River BP-4 Mill Creek PCRS at pump station forebay Mississippi River BP-5 Arsenal 23E2-163C Mississippi River L-1 Glaise Creek 26G1-203C Lower RDP L-2 Rock Creek 24G4-205C Rock Creek to Lower RDP L-3 Wherry Creek 24H4-118C Lower RDP L-4 Vernon PCRS at bank of River Des Peres channel Upper RDP L-5 January-Macklind 20G4-142C Middle RDP L-6 Tower Grove 20F4-077C Middle RDP Table 4-2 Wastewater Monitoring Summary Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-7 February 2011 The discrete overflow samples were composited to provide enough sample volume to conduct the analyses indicated in Table 4-3. Sets of four bottles were composited (e.g., bottles 1 to 4, 5 to 8, etc.) to produce a maximum of six composite samples for each site. In cases where the overflow duration was insufficient to have produced 24 discrete samples, as many composite samples were assembled as feasible from the quantities collected. 5-day Biochemical oxygen demand (BOD5) Cyanide Chemical oxygen demand (COD) Cadmium Total suspended solids (TSS) Chromium Total solids (TS) Copper Volatile suspended solids (VSS) Nickel Settleable solids (SS) Zinc Total Kjeldahl nitrogen (TKN) Arsenic Ammonia nitrogen Mercury Alkalinity Lead pH Silver Table 4-3 Wastewater Quality Parameters for Analysis As noted in Table 4-3, the samples were analyzed for pollutants typically associated with CSOs, except indicator bacteria, for which no applicable water quality standard existed at the time of the sampling program. Through discussions and correspondence with the Environmental Protection Agency and reports to them beginning in late 2005 through 2006, MSD demonstrated that pollutants of concern could be appropriately modeled using stream flow and receiving water monitoring data coupled with existing wastewater sampling results. Using the models, sensitivity analyses were conducted using a range of event mean concentrations based on bacteria concentrations from CSOs developed by other municipalities. These sensitivity analyses indicated that percent compliance with Missouri’s bacteria criteria was not significantly affected by the choice of CSO concentration. Henceforth, the District did not pursue additional wastewater sampling related to indicator bacteria. 4.5 Event Mean Concentrations Event mean concentrations were determined from the outfall characterization data. Because the sampling intervals for each CSO were intentionally skewed to sample more frequently at the beginning of a storm, the samples are not flow-proportional, and therefore cannot simply be averaged to determine the event mean concentration. To determine the flow-proportional event mean concentration, the sampling results for each sampling interval were combined with the flow recorded during that interval to determine a mass loading. The mass loadings for each interval were then totaled to determine the total loading for the event. The event mean concentration was then calculated from the total loading and the total flow for the event. The event mean data were then aggregated by receiving stream due to differences in land use in the areas tributary to the different receiving streams. Data from the Arsenal Pressure Sewer was disregarded as the results from this sampling location were heavily influenced by industrial wastewater from the Anheuser-Busch brewery that has since been separated from the combined sewer system. Finally, overall flow-proportional average concentrations were determined for each set of outfalls based on the individual event mean concentrations and event flows. Table 4-4 presents the calculated event mean concentrations. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-8 February 2011 Event Mean Concentration (mg/L) Parameter River Des Peres Mississippi River Maline Creek BOD5 36 54 32 COD 132 140 122 TS 395 590 576 TSS 294 358 404 VSS 74 83 49 SS (in mL/L) 4.6 4.0 1.4 TKN 6.4 5.4 4.7 Ammonia-N 1.21 1.37 1.53 Alkalinity 56 79 94 Cyanide N/A N/A 0.02 Arsenic 0.005 0.010 0.040 Cadmium 0.001 0.002 0.005 Chromium 0.009 0.010 0.011 Copper 0.04 0.04 0.04 Lead 0.081 0.102 0.081 Mercury 0.0003 0.0002 0.0002 Nickel 0.012 0.021 0.023 Silver 0.003 0.003 0.005 Zinc 0.18 0.21 0.20 Table 4-4 Event Mean Concentrations 4.6 Collection System Modeling Program MSD maintains a collection system model for each of the two service areas that include combined sewers – Bissell Point and Lemay. XP-SWMM was used as the modeling platform for the combined sewer areas. Flows from various separate sanitary sewer systems also enter the combined sewer systems in both service areas. These separate sanitary sewer systems were therefore modeled to account for their influence on the combined sewer system. HYDRA is MSD’s standard modeling platform for the separate sanitary sewer systems, although XP-SWMM was used extensively to model these systems for discrete events and long-term continuous simulations, due to limitations in the HYDRA software. 4.6.1 Modeling Software Selection The Storm Water Management Model (SWMM) was developed under the sponsorship of the Environmental Protection Agency in 1971. It is widely used for planning, analysis, and design of storm, sanitary, and combined sewer systems. XP-SWMM, which was developed as a third-party adaptation of the EPA SWMM, is capable of simulating the characteristics of MSD’s system and producing the required output. Because of XP-SWMM’s capabilities and wide acceptance as a suitable model, it was selected to model the combined sewer system. XP-SWMM, by XP Software Inc., is a link-node model used to simulate the full hydrologic cycle from storm water and sanitary flow generation, to routing the resultant flows through the collection system utilizing the full St. Venant equations. MSD utilized two modules in developing the combined sewer system model. The “Runoff” module develops hydrographs via nonlinear reservoir routing for input to the hydraulic components of the model, based on user-defined rainfall hyetographs, antecedent conditions, land use and topography. The “Hydraulics” module reads the Runoff hydrographs and dynamically routes the storm and sanitary flows through the collection system. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-9 February 2011 The XP-SWMM models are capable of: • Generating baseline sanitary and infiltration flows, and estimated storm flows given user-defined rainfall hyetographs; • Estimating hydraulic grade lines, volumes and flow rates of wastewater in the modeled collection system; • Estimating flow capacity of gravity sewers; • Estimating peak system flows during dry and wet weather periods; • Estimating the occurrence, duration and volume of each CSO outfall for user-defined rainfall hyetographs; • Simulating system performance using either event-specific or continuous historical data. HYDRA, by PIZER, Inc., is used by MSD to model the separate sanitary sewer system. The software is particularly suitable for generating realistic flows in the separate sanitary sewer system including diurnal base flows, infiltration, rapid infiltration, inflow, and system losses. The XP-SWMM models have been set up to receive the resultant HYDRA flows for detailed analysis of their impact (separate sanitary sewer flows) on the combined sewer system. However, HYDRA is capable of performing simulations for durations only up to 48 hours. Thus, the impact of the separate sanitary sewer system on the combined area system was modeled using XP SWMM for long-term continuous simulations. XP- SWMM was also used for many of the discrete event simulations and for instances where a thorough understanding of the separate sanitary sewer system response was not necessary (e.g., distinct identification of diurnal base flow, inflow, and infiltration components of the total sanitary flow). 4.6.2 Model Development As previously stated, the combined sewer system models use two modules within XP-SWMM, the Runoff and Hydraulic modules. The Runoff module distributes a user-defined rainfall hyetograph over the modeled sub-catchment area. Based on the characteristics of the sub-catchment area, the program estimates overland flow quantities, surface detention, infiltration losses, and evaporation losses over a user-defined time period. The output from the Runoff module is a hydrograph for input to the Hydraulics module. The following parameters are input to the Runoff module: • Precipitation • Ground Surface Area • Ground Slope • Percent Impervious Area • Characteristic Width • Ground Infiltration Parameters • Evaporation • Ground Cover Roughness • Depression Storage The Hydraulics module is essentially a node-link description of the combined sewer system whereby a series of node elements (e.g., manholes, storage tanks, pump stations, etc.) are connected by link elements (e.g., sewers, force mains). The node elements receive hydrograph input from the Runoff module or by direct user input (e.g., sanitary flow from the HYDRA models). The model then dynamically routes the received flows through the combined sewer system to the treatment plant or to CSO outfalls to receiving waters. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-10 February 2011 The following are input to the Hydraulics module: • Collection System Element Data • Pipe Roughness • Flow Diversion Elements • Base (Dry Weather) Flows • Sanitary Sewer System Wet Weather Flows • Boundary Conditions The model input selection process is fully documented in the Draft Hydraulic Model Development Report prepared in 2007. 4.6.3 Model Description and Limitations As noted in Section 3.2, the combined sewer system is present in portions of both the Bissell Point and Lemay service areas. Since these service areas are largely independent, a service area-specific model was created for each. The portions of the combined sewer system that are common to both service areas are identically represented in each model. The Bissell Point model consists of 197 Runoff module catchments representing the tributary areas to the diversions and outfalls of the service area, which includes 12 catchments that are common to both models and 7 catchments that simulate the wet weather flows from the sanitary sewer system, as shown in Figure 4-3. The flows generated by the catchments are hydraulically routed through a modeled network of approximately 1,600 elements, incorporating 130 special connections (e.g., weirs, orifices, and pump stations), to a model outlet (e.g., CSO, treatment plant, interconnection, etc.). Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-11 February 2011 Figure 4-3 Modeled Sub-catchments Similarly, the Lemay model consists of 217 Runoff module catchments representing its tributary areas, which includes the 12 common catchments and 22 catchments that simulate the wet weather flows from the sanitary sewer system, as shown in Figure 4-3. The flows generated by the catchments are hydraulically routed through a modeled network of approximately 1,800 elements, including 108 special connections, to a model outlet. Since the tributary area to Lemay Outfall 063 includes the storm sewer system in the Upper River Des Peres watershed, two models were developed to utilize the reporting characteristics of the modeling software, which provides results specific to outfalls. One model incorporated the Upper River Des Peres stream and its tributary area with the combined sewer system. This model represents the flows and characteristics for Lemay Outfall 063. A second model explicitly models the Upper River Des Peres CSOs as outfalls and does not include the receiving stream. This model represents the flows and characteristics for all other Lemay outfalls. Except in some of the large Bissell Point sub-watersheds, the combined sewer system models have not been extended beyond one reach upstream of a sub-watershed’s upstream diversion structure. The model extents are depicted in Figure 4-4. Therefore, the models are not capable of simulating the collection system response beyond this reach. Additionally, the models were calibrated to storms with a recurrence Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-12 February 2011 interval of less than or equal to two years, and, since the upstream collection system was not modeled, it is unknown whether the model will accurately simulate events possessing greater than a two-year recurrence interval, conditions which are thought to produce surface ponding and system surcharging in upstream areas of some sub-watersheds. Figure 4-4 Extents of Hydraulic Models for Lemay and Bissell Point Service Areas Due to the complex operational nature of MSD’s Overflow Regulation System and Flood Protection System, the models were not developed to simulate the exact performance of several of these systems’ components, such as the modulation of river gates in response to differential sewer/river levels under high river conditions. A sensitivity analysis was performed to approximate system response at explicit river levels by adjusting the outfall configurations to match the ORS operating conditions at that river level. The results of this sensitivity analysis, shown in Figure 4-5, indicate that the volume of CSO captured increases only minimally at higher river stages. Even at river stages that occur less than 5 percent of the time, the increased flow capture is small (less than 10 percent). This increase is due to greater storage in the collection system under high river conditions, as discussed in Section 3.2.4. Therefore, the existing hydraulic model configuration, without simulating river gate modulation, is appropriate and only slightly conservative in its results. The hydraulic model is fully capable of modeling the collection system performance during average and low river conditions, when the impacts of CSOs on receiving streams are greatest. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-13 February 2011 Additional Flow to Bissell Point Treatment Plant vs. Mississippi River Stage Exceedance Stage 5 Stage 10 Stage 15 Stage 20 Stage 30 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% % Exceedance% Additional Flow toBissell Point Treatment Plant Figure 4-5 Sensitivity of CSO Flow Capture to River Stage As noted Section 4.6.1, HYDRA is used by MSD to model the separate sanitary sewer system, but XP- SWMM was used to accurately reflect inflow and infiltration within the separate sanitary sewer system as well. The XP-SWMM models utilize ghost sub-catchments, which were initially populated using the methodology used in the combined sewer system. However, separate sanitary sewer systems are, by design, less sensitive to wet weather events compared to combined sewer systems. Therefore, the initial Runoff module parameters for catchments within the separate sanitary sewer area required a greater degree of adjustment during calibration compared to catchments within the combined sewer area. 4.6.4 Model Calibration and Verification The hydraulic models in the combined sewer system are calibrated to the rainfall and flow metering data that were collected in 2004 and 2005. The calibration of the models was verified using additional rainfall and flow data sets from the metering period. In most instances the models were calibrated using three events and verified using two independent events. The models were calibrated to the following parameters, listed in order of importance: 1. Volume 2. Hydrograph Shape 3. Peak Flow 4. Level (depth of flow) 5. Velocity The Bissell Point model was calibrated using data from 18 flow meters and the Lemay model was calibrated using data from 21 flow meters. The flow meter locations used for calibration and their tributary areas are shown in Figure 4-6. The approximate recurrence interval range for the calibration and verification events was from a three per year event to a 2-year event. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-14 February 2011 Figure 4-6 Tributary Areas of Flow Meters Used for Model Calibration The calibration and verification results generally show that simulated volumes align well with measured volumes across the wide spectrum of sewer system characteristics and storm event recurrence interval. A summary of calibration and verification results is presented in Figure 4-7. The results show that simulated volumes strongly agree with large and small measured volumes alike. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-15 February 2011 0.01 0.10 1.00 10.00 100.00 0.01 0.10 1.00 10.00 100.00 Observed Volume (MG)Simulated Volume (MG) July 24, 2004 August 25, 2004 November 1, 2004 November 11, 2004 November 24, 2004 October 23, 2004 December 6, 2004 January 12, 2005 October 18, 2004 August 24, 2004 20% over-prediction. 20% under-prediction. Figure 4-7 Summary of Model Calibration and Verification Results The separate sanitary sewer system ghost sub-catchments were calibrated in an analogous manner to the combined sewer system. The models were calibrated using flow and rainfall monitoring results from 2004 to 2005. Since the separate sanitary sewer system produces peak flows and volumes significantly smaller than combined sewer systems, a rigorous calibration was not warranted. Nonetheless, the models were calibrated using two to three events. The models were calibrated to the following parameters, listed in order of importance: 1 hydrograph shape 2 peak flow 3 volume The separate sanitary sewer service areas were calibrated using 5 flow meters in the Bissell Point service area and 14 flow meters in the Lemay service area. These meters were typically located at the downstream portions of the separate sanitary sewer system within each watershed. Though the models were calibrated and verified in January 2006, they are updated as new information, particularly hydraulic data (e.g., surveys, new sewers, etc.) in areas where flow meter information was not available for calibration, becomes available. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 4. SEWER SYSTEM CHARACTERIZATION, MONITORING, & MODELING Page 4-16 February 2011 4.7 Model Results MSD has applied its hydraulic models to estimate the occurrence, volumes and peak flow rates associated with combined sewer overflows for the typical year (year 2000) rainfall. Overflow volumes were extracted from the resulting XP-SWMM outfall hydrographs, which consist of an average flow based on 15-minute time intervals. The estimated system-wide CSO volume for the typical year is 13.3 billion gallons. Receiving Waters CSO Volume (billion gallons) Number of Overflow Events River Des Peres and tributaries 6.15 62 Maline Creek 0.15 29 Gingras Creek 0.02 33 Mississippi River 6.95 65 Total 13.3 Table 4-5 Hydraulic Model Results for Typical Year (2000) Appendix B contains a summary, by outfall, of the annual overflow volumes and peak flows, the range in event overflow volumes, and the number of overflow events per year. The occurrence of overflow events is based on a 6-hour inter-event time period. The annual overflow volume noted above and detailed in the referenced appendix represents current conditions as described in Section 3.2 of this report, with the following exceptions: • the additional flow capture resulting from the new Bissell Point Pump Station flow control strategy (flow-control set-points) that was implemented in 2007 is not represented in the baseline, • the additional flow capture resulting from the Lemay Treatment Plant improvement project, currently under construction, is not represented in the baseline, and • reduced overflow volumes resulting from several small combined sewer separations that are currently in design or construction, are not represented in the baseline. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-1 February 2011 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING 5.1 Introduction This section describes additional work done to characterize the CSO receiving waters, including water quality monitoring and modeling. It is intended to complement two documents previously issued by MSD: the Final Water Quality Study Report: CSO Long-Term Control Plan Update (LimnoTech, 2006) and the Receiving Water Model Development: CSO Long-Term Control Plan Update (LimnoTech, 2006). 5.2 Previous Receiving Water Characterization, Monitoring and Modeling In 2006, MSD issued two reports that summarized the extent of receiving water characterization, monitoring and modeling up to that point. The Water Quality Study Report (LimnoTech, 2006) was prepared in response to EPA’s 308 Information Request, and summarized receiving water quality data collected by MSD and USGS through October, 2005. The report identified dissolved oxygen (DO) and bacteria as “parameters of concern” for the River Des Peres and Maline Creek, and recommended the use of receiving water models to evaluate CSO impacts on these parameters. The report also recommended that models be used to confirm that criteria exceedances of ammonia in the River Des Peres and Maline Creek, which was included in previous studies as a “potential parameter of concern,” are not caused by CSOs. The report concluded that neither DO nor bacteria should be considered parameters of concern for the Mississippi River, and that water quality modeling was not required. A review of additional data collected in these streams through calendar year 2008 was conducted, and the conclusions of the original report continue to be supported. Relevant tables and figures from the 2006 report have been updated, and are included in Appendix C. The Receiving Water Model Development Report (LimnoTech, 2006) summarized the development of hydrologic, hydraulic and water quality models of the River Des Peres and Maline Creek, and presented an assessment of water quality impacts based on a “typical year” scenario. Data for calibration of these models was limited, especially for wet weather water quality, and application of the models identified various data gaps that needed to be addressed. With these limitations in mind, the report concluded that compliance with chronic DO criteria was potentially an issue in backwater-affected areas, but not likely an issue elsewhere. Compliance with acute ammonia criteria was not expected to be an issue in any of the receiving water bodies. The report also concluded that bacteria concentrations could exceed certain criteria at various locations, but that compliance could not be addressed directly because the water bodies were not currently designated for recreational uses. Finally, the report concluded that, based on the modeling results, complete removal of CSOs would not eliminate the potential for compliance issues for the parameters of concern. 5.3 Receiving Water Monitoring Although the existing water quality monitoring programs have been generally adequate to characterize the receiving streams, development of the water quality models revealed several gaps in data collection. For example, the dynamic response of the receiving streams to wet weather loads had not been characterized by collection of multiple, timed samples throughout the course of a wet weather event. Also, DO data were limited to grab samples, which do not provide an assessment of compliance with both minimum and average criteria, as would continuous monitoring with data sondes. To help fill these gaps, supplemental monitoring was conducted in 2007 and 2008 on the River Des Peres and Maline Creek in addition to the routine data collection performed by MSD and other Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-2 February 2011 contractors, which is not described here. The supplemental monitoring included wet weather survey sampling for multiple events, continuous monitoring for DO, pH, temperature and conductivity, and routine sample collection at several tributary sites that represented the upstream boundaries of the modeled receiving waters. Each of these aspects of the sampling program is discussed below. 5.3.1 Wet Weather Surveys Wet weather survey sampling involves collection of samples at timed intervals throughout the course of a wet weather event. The collection frequency and total number of samples is determined largely by the response time of the watershed, but may also be subject to geographic and personnel constraints. For the 2007 wet weather surveys, a total of five samples were collected at each site, at the (approximate) event times of 0, 12, 24, 48 and 72 hours. In 2008, when additional surveys were conducted on the Upper River Des Peres, an additional sample was collected at 96 hours into each event, for a total of six samples at each location. Table 5-1 lists the sampling locations for each water body; they are depicted in Figures 5-1 through 5-3. The locations were chosen to provide coverage of as much of each model domain as possible, including the upstream boundary. Safe, 24-hour access was also a consideration, which led to the selection of overpasses for most of the sites. The locations were revised in 2008 for the Upper River Des Peres, as noted in the table. Analysis of each sample included water chemistry parameters determined at the time of sampling, as well as laboratory parameters; these are listed in Table 5-2. Two events were successfully sampled in 2007, although the results from the Upper River Des Peres were not entirely satisfying and prompted refinement of the model configuration, followed by collection of two wet weather events in 2008 for this water body only. Table 5-3 summarizes the dates and total rainfall, as determined by radar monitoring in each watershed, for the four events. Full results of the sampling are provided in Appendix D. Receiving Water Location ID Description Events Sampled LRdP-1 South Broadway LRdP-2 Morgan Ford Road LRdP-3 Gravois Avenue LRdP-4 Chippewa Street LRdP-5 Arsenal Street Lower and Middle River Des Peres LRdP-6 Macklind Avenue Oct 2007; Nov 2007 MCr-1 Riverview Road MCr-2 Bellefontaine Road Maline Creek MCr-3 Lewis and Clark Blvd Oct 2007; Nov 2007 URdP-1 Vernon Avenue URdP-2 Ferguson Avenue (Pagedale Branch) Upper River Des Peres (original sampling) URdP-3 North & South Road Oct 2007; Nov 2007 URdP-1 Woodson Road (Jun); Dielman Drive (Sep) URdP-2 North & South Road URdP-3 Purdue Avenue URDP-4 Vernon Avenue Hanley1 Pennsylvania Ave (Pagedale Branch) Hanley2 Etzel Road (Pagedale Branch) Upper River Des Peres (revised sampling) Mendell Canton Avenue (Vinita Park Branch) Jun 2008; Sep 2008 Table 5-1 Sample Locations for Wet Weather Surveys Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-3 February 2011 Figure 5-1 2007-2008 Monitoring Program: Lower and Middle River Des Peres Figure 5-2 2007-2008 Monitoring Program: Maline Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-4 February 2011 Figure 5-3 2007-2008 Monitoring Program: Upper River Des Peres Parameter Method(s) Ammonia EPA 350.3; SM (18) 4500 NH3 B,H Nitrate EPA 300.0 R2.1; SM (18) 4500 NO3 F Total Kjeldahl Nitrogen EPA 351.1; SM (18) 4500 NH3 H 5-Day Carbonaceous Biochemical Oxygen Demand SM (18) 5210B E. coli EPA 1603; SM (18) 9222D MOD Table 5-2 Water Quality Parameters Analyzed in Wet Weather Survey Sampling Total Rainfall by Watershed (Inches) Event ID Dates Lower River Des Peres Maline Creek Upper River Des Peres 1 October 3 – October 6 (2007) 0.79 0.87 0.79 2 November 12 – November 15 (2007) 0.41 0.65 0.59 3 June 13 – June 17 (2008) -- -- 0.33 4 September 4 – September 8 (2008) -- -- 3.4 Table 5-3 Summary of Wet Weather Events 5.3.2 Continuous Monitoring Continuous monitoring of DO served two purposes in the supplemental receiving water characterization. First, the water quality standards include a criterion for daily minimum DO concentration, and the presence of any diurnal variation resulting from photosynthesis and respiration means that grab sampling would not necessarily find the minimum value. Continuous monitoring, on the other hand, will pick up the minimum value at a given location regardless of when it occurs. Second, the original water Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-5 February 2011 quality models predicted depressed DO in backwater-affected reaches of both the River Des Peres and Maline Creek, but no data had been collected in such areas previously. Deployment of data sondes at locations susceptible to backwater influence, however, would likely obtain this kind of data without having to mobilize sampling crews in response to specific conditions, provided the sondes were left in place long enough. Table 5-4 summarizes the locations and time periods where data were collected with sondes. The locations are also called out in Figures 5-1, 5-2 and 5-3. A standard membrane type of probe was used for DO, which resulted in several data gaps due to fouling; generally, however, a good amount of usable data were obtained. Section 5-9 presents comparisons between sonde data and model results for DO. Appendix E contains all of the sonde data. Sonde Location Monitoring Period Lower River Des Peres South Broadway 6/22/2007 - 9/14/2007 Morgan Ford Road 10/25/07 - 11/16/2007 Maline Creek Riverview 6/23/2007 - 9/14/2007 Lewis & Clark Boulevard 11/9/2007 - 12/5/2007 Upper River Des Peres Purdue Avenue 5/22/2008 -10/31/2008 Woodson 5/22/2008 - 6/24/2008 Pennel Street 8/11/2008 -8/27/2008 Table 5-4 Summary of Continuous Monitoring Locations 5.3.3 Tributary and Upstream Boundary Sampling The receiving water models require specification of pollutant loads at upstream boundaries, and from tributaries that are not modeled explicitly. The existing data collection program, while comprehensive, does not specifically include all pertinent locations with respect to the receiving water model data needs, which leaves open the question of variation in pollutant load characteristics among the different watersheds. In the previous modeling effort, uniform concentrations were assumed to apply to all upstream and tributary boundary conditions, and the sensitivity of model results to this approach was examined by performing runs using either “low range” or “high range” concentrations. For the purposes of assessing water quality over the course of a typical year, the models are not very sensitive to the assumed values for boundary concentrations; however, more information was desired. Additional locations were added to MSD’s routine water quality sampling program, specifically to provide data for upstream boundaries and unmonitored tributaries. The additional sample locations are listed in Table 5-5, and shown in Figures 5-1, 5-2 and 5-3. A total of 12 samples were collected from each location at approximately biweekly intervals from late April to mid- September. Eleven of these samples represented dry weather conditions, and one represented wet weather. A statistical summary of the results for relevant parameters is given by Figure 5-4 and Table 5-6. In Figure 5-4, box-and-whisker plots compare the distribution of pollutant concentrations at individual sites with the distribution for all sites considered together. Although the median values differ somewhat among the sites for each pollutant, there do not appear to be consistent trends at particular locations; that is, one site is not consistently higher or lower in concentrations for all pollutants in comparison with all the sites as a whole. This suggests that the approach taken in the original modeling, the assumption of uniform concentrations at all boundaries, was not unreasonable. For the revised water quality models, the original “high range” concentrations were retained, subject to some adjustment in the calibration process, as discussed subsequently. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-6 February 2011 Water Body Receiving Water Location ID Description Maline Creek MC212 East side of bridge on Lewis & Cark Blvd. just south of Marquis Ct. (Wunnenberg p.18 H-11) Maline Creek MC460 East side of bridge on West Florissant just south of Northwinds Est. Dr. (Wunnenberg p.17 K-11) Blackjack Creek Maline Creek Blackjack South side of bridge on Vorhof Dr. just south of New Halls Ferry Rd. (Wunnenberg p.10 I-9) MacKenzie Creek Lower River Des Peres MacKenzie From walking trail bridge along River Des Peres Blvd. a little south of Watson Rd. (Wunnenberg p.36 M-25) Vinita Park Branch Vinita Park South side of bridge on Canton Dr. just west of Mendell Dr. (Wunnenberg p.25 P-17) Pagedale Branch Upper River Des Peres Pagedale South side of sidewalk bridge on Page Blvd. just west of Pennsylvania Ave. (Wunnenberg p.25 M-17) Table 5-5 Locations for Tributary and Upstream Boundary Sampling Figure 5-4 Summary of Tributary and Upstream Boundary Sampling Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-7 February 2011 E. coli (#/100 mL) All Sites Blackjack MacKenzie MC212 MC460 Pagedale Vinita Park Minimum 9 120 27 9 36 27 73 1st Quartile 91 165 50 49.75 77.5 52 280 Median 150 200 73 100 130 145 360 3rd Quartile 300 217.5 110 117.5 255 277.5 1270 Maximum 4800 1300 190 280 495 480 4800 N 61 10 9 10 11 10 11 Ammonia (mg/L) All Sites Blackjack MacKenzie MC212 MC460 Pagedale Vinita Park Minimum 0.04 0.05 0.052 0.042 0.04 0.136 0.046 1st Quartile 0.079 0.078 0.08225 0.0635 0.069 0.212 0.1085 Median 0.126 0.091 0.161 0.082 0.084 0.293 0.122 3rd Quartile 0.198 0.154 0.1885 0.138 0.1235 0.4525 0.385 Maximum 2.3 0.254 2.28 0.844 0.23 0.732 2.3 N 65 11 10 11 11 11 11 Nitrate (mg/L) All Sites Blackjack MacKenzie MC212 MC460 Pagedale Vinita Park Minimum 0.1 0.1 0.13 0.16 0.13 0.34 0.1 1st Quartile 0.35 0.115 0.515 0.29 0.31 0.43 0.4975 Median 0.6 0.315 0.72 0.435 0.51 0.65 0.73 3rd Quartile 0.8 0.595 0.795 0.67 0.68 0.83 0.9875 Maximum 1.38 0.85 1.33 1.36 0.8 1.38 1.32 N 45 4 7 6 7 11 10 DO %Sat (--) All Sites Blackjack MacKenzie MC212 MC460 Pagedale Vinita Park Minimum 46% 75% 79% 66% 70% 46% 103% 1st Quartile 76% 100% 97% 74% 74% 61% 118% Median 98% 110% 99% 82% 82% 69% 129% 3rd Quartile 116% 127% 112% 96% 91% 82% 146% Maximum 177% 160% 144% 102% 101% 104% 177% N 65 11 10 11 11 11 11 Table 5-6 Statistical Summary of Upstream Boundary Sampling 5.4 Updates to Hydrologic and Hydraulic Models The hydrologic and hydraulic models of the River Des Peres and Maline Creek were updated for application to the LTCP. The configurations of the SWMM5 models were largely unchanged, although parameters were adjusted to refine the calibration, based on new information. The FEQ models underwent more extensive refinement, however, primarily to better support the wet weather event predictions of the water quality models. Subsequent sections present calibration results for each tributary water in terms of wet weather flow comparisons, and include discussions of the model adjustments and refinements that were made to achieve the calibrated results. 5.4.1 Lower River Des Peres The original SWMM5 model was not altered, in terms of the representation of catchment areas and the configuration of open channels. However, adjustments were made to impervious area, infiltration and width of overland flow to calibrate the model to wet weather flow data from various USGS gages. The gages used for the calibration are listed in Table 5-7. In addition to hydrologic adjustments, some changes were made in the representation of open channels. The goal of these changes was to reduce system conveyance slightly and achieve a more realistic degree of “flashiness” in the runoff behavior. The final arrangement of the SWMM5 model is depicted in Figure 5-5. The input data for the Lower River Des Peres SWMM5 model are summarized in Appendix F. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-8 February 2011 USGS Gage ID Name 07010075 Deer Creek at Ladue, MO 07010086 Deer Creek at Maplewood, MO 07010090 MacKenzie Creek near Shrewsbury, MO 07010180 Gravois Creek near Mehlville, MO 07005000 Maline Creek at Bellefontaine Neighbors, MO 07010022 River Des Peres near University City, MO 07010030 River Des Peres Tributary at Pagedale, MO Table 5-7 USGS Gages for Calibration of Hydrologic Models Figure 5-5 Configuration of SWMM5 Model of the Lower and Middle River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-9 February 2011 Two different sources of rainfall data were used to drive the SWMM5 model. Through September, 2007, rainfall data were obtained from the network of stationary gages used by MSD in recent years. Beginning in October, 2007, rainfall inputs were derived from radar measurements provided by a vendor contracted by MSD. The locations of the stationary gages are shown in Figure 5-5. Revisions to the FEQ model included transect surveys at various points between the Mississippi River and the confluence with Gravois Creek, to better define bottom slope and channel volume during backwater influence. Other hydraulic modifications were made to increase the depth, and thus reduce the velocity, during lower flow periods; this effort was prompted by the results of the wet weather survey data, which is discussed in a subsequent section of this report. The modifications include revisions to cross section geometry, increases in roughness, and the placement of several low-head weir structures at various locations along the channel. The arrangement of the revised FEQ model is shown in Figure 5-6, which includes model nodes, weir structures, and the location of transect survey data collection. Figures 5-7 through 5-10 compare model flows to USGS gage data at four locations, for a series of wet weather events in June, July and September of 2007. In general, the SWMM5 model is responsive to rainfall and produces total volumes and peak flow rates that compare well to the gage data. There is a tendency for the predicted peak flows on Deer Creek to exceed the gage values, but the overall volumes are similar; some additional storage is provided at the downstream end of this channel, before it is input to the FEQ model for linkage with the water quality model. The peak flow rates and volumes at MacKenzie Creek and Gravois Creek (Figures 5-9 and 5-10, respectively) are generally consistent with gage data over the range of event sizes modeled. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-10 February 2011 Figure 5-6 Configuration of FEQ/EUTRO Model of the Lower and Middle River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-11 February 2011 Figure 5-7 SWMM5 Calibration to 2007 Events: Deer Creek at Ladue Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-12 February 2011 Figure 5-8 SWMM5 Calibration to 2007 Events: Deer Creek at Maplewood Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-13 February 2011 Figure 5-9 SWMM5 Calibration to 2007 Events: MacKenzie Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-14 February 2011 Figure 5-10 SWMM5 Calibration to 2007 Events: Gravois Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-15 February 2011 5.4.2 Maline Creek As with the Lower River Des Peres model, the SWMM5 model of Maline Creek was unchanged except for some hydrologic parameters that were adjusted to achieve a better calibration to new data. USGS gage data were only available at Bellefontaine Neighbors, which represents the upstream boundary of the FEQ model. The configuration of the SWMM5 model is shown in Figure 5-11, which also includes the stationary rain gages used for events through September, 2007. All input data for the model are summarized in Appendix F. The FEQ model was more extensively revised, using transect survey data from multiple locations. As with the Lower River Des Peres, hydraulic modifications were made to reduce the velocity and increase the depth under lower flow conditions. Figure 5-12 shows the location of nodes, weir structures, and transect survey points for the revised FEQ model of Maline Creek. Figure 5-13 compares modeled flows with gage measurements at Bellefontaine Neighbors. The peak flows and overall volumes compare consistently well over the range of events simulated. Figure 5-11 Configuration of SWMM5 Model of Maline Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-16 February 2011 Figure 5-12 Configuration of FEQ/EUTRO Model of Maline Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-17 February 2011 Figure 5-13 SWMM5 Calibration to 2007 Events: Maline Creek at Bellefontaine Neighbors Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-18 February 2011 5.4.3 Upper River Des Peres As with the other SWMM5 models, the hydrology of the Upper River Des Peres was recalibrated while retaining the same general configuration as in the original modeling effort. The SWMM5 model is shown in Figure 5-14, with additional input data summarized in Appendix F. The FEQ model underwent considerable refinement. The original model was derived from an XP- SWMM model that included only the engineered channel; for this effort, the model domain was expanded to include a reach of the Upper River Des Peres extending upstream from the confluence with the Vinita Park branch (near Olive Boulevard) to Woodson Park. This expanded domain is shown in Figure 5-15. Difficulties in obtaining suitable wet weather survey samples led to an additional sampling event in 2008. For this reason, the hydrologic and hydraulic calibration of the models was examined in both 2007 and 2008. Radar-derived rainfall data was used for wet weather events in the fall of 2007 and throughout 2008, although a different vendor supplied the data beginning in January 2008. Calibration results are shown in Figures 5-16 and 5-17 for USGS gage locations on the Upper River Des Peres and the Pagedale Branch, respectively. The model results are actually shown for transects in the FEQ model, because the gage locations are within this model rather than the SWMM5 model. The peak flow comparison is generally quite good. There is a tendency for the receding limbs of wet weather hydrographs to be extended a bit in the model, relative to the data, but this has the effect of improving the water quality predictions for reasons that will be explained subsequently. Figure 5-14 Configuration of SWMM5 Model of the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-19 February 2011 Figure 5-15 Configuration of FEQ/EUTRO Model of the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-20 February 2011 Figure 5-16 SWMM5 Calibration 2007/2008 Events: Upper River Des Peres at Purdue Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-21 February 2011 Figure 5-17 SWMM5 Calibration 2007/2008 Events: Upper River Des Peres Tributary at Pagedale Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-22 February 2011 5.5 Updates to Water Quality Models Several water quality process representations were added to the models to facilitate the calibration and improve their predictive value. These representations take advantage of enhancements to the EUTRO code that LimnoTech has made for previous applications involving urban wet weather flow situations. The modifications are described below, followed by a discussion of the calibration and validation of the models to the wet weather survey data collected in 2007 and 2008. 5.5.1 Photosynthesis and Respiration The processes of photosynthesis and respiration (PR) by aquatic plants result in a diurnal variation in dissolved oxygen (DO), in response to sunlight. It is important to include this variation when assessing attainment of water quality standards based on daily minimum concentration criteria for DO. Model representations of this phenomenon range in complexity, from empirical parameterizations to sophisticated eutrophication models that include multiple algal species. The EUTRO model framework can simulate a single group of algae as a state variable, but to do so involves simulating other parameters and collecting considerably more data. An alternative formulation that is simpler to implement, but still provides a useful simulation of observed diurnal variations, is described by Chapra (1997), with more details provided in Appendix G. The EUTRO code has been modified to allow this representation to be used where deemed appropriate. To implement this PR scheme, solar radiation data must be supplied. Direct measurements were not available for the St. Louis area, so cloud cover data from Lambert-St. Louis International Airport were used to estimate radiation, using tools developed for HSPF (Bicknell et al., 2005). Algal density is represented by a chlorophyll-a concentration parameter, which can be varied both in time and (to a limited extent) in space. Finally, light extinction is specified for individual model segments, and this also can be varied in time to simulate the effects of wet weather and other transient phenomena. The values used in the model were derived during calibration and are discussed subsequently. 5.5.2 Multiple Sources of Bacteria and CBOD In the original models, bacteria and carbonaceous biochemical oxygen demand (CBOD) were each represented by a single state variable, subject to removal only by first-order decay. The EUTRO code was modified, however, to include multiple bacteria and CBOD variables that can represent different sources, each with its own decay rate as well as a settling mechanism. For example, bacteria and CBOD from CSOs, which tend to be strongly associated with particulate matter, can be assigned a greater particulate fraction and higher settling rate than ambient upstream sources. It is recognized that this sort of representation requires additional parameters that can not generally be measured directly. However, the motivation for including these mechanisms is that a single state variable, with only first-order decay, is not always able to adequately describe the observed water quality variations, and by adjusting these additional parameters within reasonable ranges, a better calibration is achieved. The calibrated settling parameters are discussed subsequently for the various receiving water models. 5.6 Lower River Des Peres Calibration and Validation The October 2007 event was used to calibrate the Lower River Des Peres (LRDP) water quality model, with the November 2007 event reserved for validation. Calibration involved adjustment of many of the kinetic parameters in the water quality as well as storm water pollutant concentrations; kinetic parameters are summarized in Table 5-8 and pollutant concentrations in Table 5-9. Further, the hydraulic behavior of the model was modified considerably to simulate the residual effects of wet weather flows that were revealed by the survey sampling. As originally developed, the model tended to convey wet weather flows very quickly, and return to base flow conditions after a short period of time. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-23 February 2011 While this “flashy” behavior is consistent with general observations, the wet weather survey data (which had not been collected previously) indicated that the effects of wet weather flows were somewhat more persistent. Various modifications were required to reduce the velocity of low flows in the river bed, and prevent water from moving through the system too quickly. Parameter Units Value CBOD - CSO Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.5 Settling Velocity m/day 2.0 CBOD - Storm Water Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.5 Settling Velocity m/day 0.5 Organic Nitrogen Mineralization Rate day-1 0.1 Particulate Fraction -- 0.5 Settling Velocity m/day 0.1 Ammonia Nitrification Rate day-1 0.2 E. coli - CSO Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.75 Settling Velocity m/day 2.0 E. coli - Storm Water Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.5 Settling Velocity m/day 0.5 E. coli - Upstream Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.25 Settling Velocity m/day 0.5 Segment Specific Parameters Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) 1 0.0 60 12 1.0 60 23 3.0 240 2 0.0 60 13 1.0 60 24 2.0 240 3 0.5 60 14 1.0 120 25 2.0 180 4 0.5 60 15 1.0 120 26 2.0 180 5 0.5 60 16 1.0 120 27 2.0 180 6 0.5 60 17 1.0 120 28 2.0 250 7 0.5 60 18 2.0 120 29 2.0 250 8 0.5 60 19 2.0 120 30 2.0 250 9 0.5 60 20 2.0 240 31 2.0 250 10 1.0 60 21 3.0 300 11 1.0 60 22 3.0 300 Table 5-8 Kinetic Parameters for the Lower River Des Peres EUTRO Model Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-24 February 2011 CSO Storm Water Parameter Units 1st hour 2nd hour Balance 1st hour 2nd hour Balance Ammonia mg/L 1.4 1.4 1.4 0.7 0.7 0.1 Nitrate mg/L 0.5 0.5 0.5 2.5 2.5 0.2 Organic Nitrogen mg/L 5.2 5.2 5.2 3.0 2.0 0.5 CBOD5 mg/L 35 35 35 30 30 2.0 Dissolved Oxygen mg/L 1.0 1.0 1.0 3.0 3.0 4.0 E. coli #/100 mL 500,000 200,000 200,000 150,000 150,000 1,000 Table 5-9 CSO and Storm Water Pollutant Concentrations for the Lower River Des Peres The channel cross sections include a smaller sub channel that conveys dry weather flows. This channel was enlarged considerably, so that low velocities were generally less than 0.5 feet per second. This afforded considerable improvement in the representation of wet weather water quality effects. Further modifications included placement of several weir-like structures, to create a sort of “pool and riffle” structure in the low-flow channel that was more consistent with observations. These features are quickly overwhelmed by wet weather flows, however. 5.6.1 Calibration Event: October 2007 Figure 5-18 shows the calibration results for dissolved oxygen (DO) in the LRDP. The six sample locations are arranged from upstream (Macklind Avenue) to downstream (South Broadway). The Macklind Avenue data were actually used as upstream boundary concentrations, which explains the close correspondence seen at that location. The best results are seen at the more downstream locations, in particular Gravois Avenue and Morgan Ford Road. In these areas, the PR parameters and sediment oxygen demand (SOD), in combination with the hydraulic modifications, were able to account for the attenuated recovery of DO following the event. At Arsenal and Chippewa, however, the channel is mostly concrete and the assumption of considerable SOD and PR is not very realistic, so these parameters were not exaggerated simply to achieve a better fit to the data. The calibration to E. coli bacteria is shown in Figure 5-19. The model captures the peak concentrations at the very beginning of the event, followed by a gradual reduction over the course of several days. The inclusion of the settling mechanism was important in achieving the observed rate of decline, which was somewhat greater in the upstream locations that are dominated by CSO over tributary storm water sources like Deer Creek and Gravois Creek. The CSO sources are assumed to have a greater particulate fraction and higher settling velocity than the storm water sources (see Table 5-8). Figure 5-20 shows the calibration results for ammonia. The sampling results did not portray a clear trend of elevated initial concentrations followed by a gradual return to dry weather levels, but instead showed a delayed effect. The model results are consistent with the formulation and inputs: a spike in concentration associated with the CSO inputs, and a gradual attenuation of the upstream boundary concentration profile as it passes through the system. The data appear to suggest an increase in ammonia concentration at downstream locations around the third day of the event, but there is no compelling physical evidence of a source that would explain the increase. Figures 5-21 and 5-22 show results for two other forms of nitrogen that are included in the model: organic nitrogen and nitrate. Organic nitrogen is included in the model because it mineralizes to ammonia in aquatic systems, and thus acts as a source; nitrate is included simply because it is the end product of ammonia oxidation. For organic nitrogen, the model shows a brief spike resulting from CSO discharges that is not seen in the data. This spike could be eliminated by assuming a much lower CSO concentration for organic nitrogen, but this is not a realistic approach. The key reason for modeling Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-25 February 2011 organic nitrogen in the model is to include its potential for conversion to ammonia, which is captured in the decay rate. As for nitrate, the modeled profile is reasonable although the initial concentrations are low at the downstream sites. Because nitrate is not a pollutant of concern, a more robust simulation is not required. Figure 5-23 shows the calibration results for CBOD5. As with organic nitrogen, there is a sharp spike at the beginning of the event that is not seen so prominently in the data. The modeled decline in concentration may be somewhat greater than observed, although many of the sample results were below the limit of detection, making comparison difficult. During calibration of the model it was seen that DO concentration was not very sensitive to CBOD5 load and decay rate, so these parameters were not exaggerated simply to mimic the sampling results. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-26 February 2011 Figure 5-18 Lower River Des Peres: Dissolved Oxygen Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-27 February 2011 Figure 5-19 Lower River Des Peres: E. coli Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-28 February 2011 Figure 5-20 Lower River Des Peres: Ammonia Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-29 February 2011 Figure 5-21 Lower River Des Peres: Organic Nitrogen Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-30 February 2011 Figure 5-22 Lower River Des Peres: Nitrate Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-31 February 2011 Figure 5-23 Lower River Des Peres: CBOD5 Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-32 February 2011 5.6.2 Validation Event: November 2007 After calibrating the model to the October 2007 event, comparisons were made to the November 2007 event for model validation. This second event was smaller in terms of total rainfall, with what appeared to be higher concentrations of pollutants at several sampling stations. The modeled results are compared with the sampling data in Figures 5-24 through 5-29. Modeled DO concentrations capture the general sag but do not always drop as low as the data during the initial stages of the event, especially at lower stations. As mentioned during the discussion of calibration, numerous methods were employed to “slow down” the hydraulic response of the system, retaining wet weather volumes for longer periods. This approach served the calibration well, and although the validation event does not reproduce the lowest DO concentrations, the length of time to recover from the event is similar. Measured bacteria concentrations (Figure 5-25) seemed to be higher for this event; although the kinetic response of the model is reasonable. Reproducing the higher in-stream concentrations would have required using considerably higher CSO and storm water bacteria levels, which would be inappropriate for the calibration event. Ultimately a single value needs to be used for the typical year water quality evaluations, and the values used for the calibration event are adequate and representative. Higher concentrations were also observed for the nitrogen species and for CBOD5. Note that the Macklind Avenue concentrations are used as boundary conditions, and that the model simulates the dissipation of these concentrations fairly well, although some ammonia appears to remain in the system longer than observed (Figure 5-26). The CBOD5 concentrations at downstream stations appear higher in the validation event, but an argument similar to that for bacteria can be made, in using the calibration concentrations for typical year simulations. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-33 February 2011 Figure 5-24 Lower River Des Peres: Dissolved Oxygen Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-34 February 2011 Figure 5-25 Lower River Des Peres: E. coli Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-35 February 2011 Figure 5-26 Lower River Des Peres: Ammonia Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-36 February 2011 Figure 5-27 Lower River Des Peres: Organic Nitrogen Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-37 February 2011 Figure 5-28 Lower River Des Peres: Nitrate Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-38 February 2011 Figure 5-29 Lower River Des Peres: CBOD5 Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-39 February 2011 5.7 Maline Creek Calibration and Validation The October 2007 event was also used for calibration of the revised water quality model of Maline Creek. Tables 5-10 and 5-11 summarize the calibrated kinetic coefficients and pollutant concentrations, respectively. Like the LRDP, the Maline Creek model underwent considerable hydraulic modification to achieve slower overall velocities during low flows. Transect survey data were used (see Figure 5-12 for locations) to develop more realistic cross sections through much of the length of the creek, along with low-head weirs as in the LRDP. Parameter Units Value CBOD - CSO Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.5 Settling Velocity m/day 3.0 CBOD - Storm Water Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.5 Settling Velocity m/day 0.5 Organic Nitrogen Mineralization Rate day-1 0.01 Particulate Fraction -- 0.5 Settling Velocity m/day 0.5 Ammonia Nitrification Rate day-1 0.2 E. coli - CSO Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.75 Settling Velocity m/day 3.0 E. coli - Storm Water Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.5 Settling Velocity m/day 0.5 E. coli - Upstream Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.5 Settling Velocity m/day 0.75 Segment Specific Parameters Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) 1 4.0 40 5 4.0 40 9 3.0 120 2 4.0 40 6 4.0 40 10 3.0 120 3 4.0 40 7 4.0 120 11 3.0 120 4 4.0 40 8 4.0 120 12 3.0 Table 5-10 Kinetic Parameters for the Maline Creek EUTRO Model Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-40 February 2011 CSO Storm Water Parameter Units 1st hour 2nd hour Balance 1st hour 2nd hour Balance Ammonia mg/L 1.5 1.5 1.5 0.7 0.7 0.1 Nitrate mg/L 0.5 0.5 0.5 2.5 2.5 0.1 Organic Nitrogen mg/L 3.2 3.2 3.2 3.0 2.0 0.5 CBOD5 mg/L 32 32 32 30 30 2.0 Dissolved Oxygen mg/L 1.0 1.0 1.0 3.0 3.0 4.0 E. coli #/100 mL 500,000 200,000 200,000 150,000 150,000 1,000 Table 5-11 CSO and Storm Water Pollutant Concentrations for Maline Creek 5.7.1 Calibration Event: October 2007 Figures 5-30 through 5-35 show the calibration results for the modeled pollutants in Maline Creek. The three sample locations are arranged from upstream (Lewis and Clark Boulevard) to downstream (Riverview Road). The Lewis and Clark data were used as upstream boundary concentrations, although the sampling station is about 0.34 miles downstream of the model boundary; the model correspondence seen at that location is close to the data, but shows some transformation. The agreement between model and data at the other sampling locations is good for DO and E. coli bacteria, and reasonable for the nitrogen parameters and for CBOD5. The initial profiles of ammonia and nitrate undergo a spreading effect in the model that is somewhat less pronounced in the data. This effect is unavoidable to some extent but has been minimized by specifying a low amount of longitudinal dispersion in the EUTRO model. The distance between the Lewis and Clark and Riverview stations is about 1.8 miles, which does not allow for substantial decay except at low, dry weather flows. Like the LRDP model, the Maline Creek model does a reasonable job of characterizing the transport and decay of the pollutants of concern. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-41 February 2011 Figure 5-30 Maline Creek: Dissolved Oxygen Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-42 February 2011 Figure 5-31 Maline Creek: E. coli Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-43 February 2011 Figure 5-32 Maline Creek: Ammonia Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-44 February 2011 Figure 5-33 Maline Creek: Organic Nitrogen Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-45 February 2011 Figure 5-34 Maline Creek: Nitrate Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-46 February 2011 Figure 5-35 Maline Creek: CBOD5 Calibration, October 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-47 February 2011 5.7.2 Validation Event: November 2007 The November 2007 event was used as a validation check for the Maline Creek model. The results are shown in Figures 5-36 through 5-41. As with the LRDP model, the modeled DO for the validation event tended to be higher than was observed. The E. coli comparison is good, with perhaps a little less decay/settling than observed. The nitrogen species show that, during this event, there is not a lot of spatial variation in the parameters; that is, the concentrations vary little from station to station. This slow kinetic transformation is reproduced by the model. This observation also holds for CBOD5. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-48 February 2011 Figure 5-36 Maline Creek: Dissolved Oxygen Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-49 February 2011 Figure 5-37 Maline Creek: E. coli Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-50 February 2011 Figure 5-38 Maline Creek: Ammonia Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-51 February 2011 Figure 5-39 Maline Creek: Organic Nitrogen Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-52 February 2011 Figure 5-40 Maline Creek: Nitrate Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-53 February 2011 Figure 5-41 Maline Creek: CBOD5 Validation, November 2007 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-54 February 2011 5.8 Upper River Des Peres Calibration and Validation The configuration of the revised model of the Upper River Des Peres (URDP) is depicted in Figure 5-15. Samples were collected during the October and November 2007 wet weather events based on the original configuration of the model, but for several reasons these samples were not well-suited for calibration; for example, certain locations essentially dried up within 48 hours of the wet weather flow. This situation prompted the reconfiguration of the model, including the extension of the model domain along the main stem of the URDP upstream to Woodson Road (see section 5.4.3). Two additional wet weather events were sampled, using revised sampling locations, in 2008. The second event, in early September, had about 3.4 inches of rain and was used as the calibration event. The first event, in June, was smaller (0.33 inches) and was used as the validation event. A dry weather sewage overflow occurred during this event, which had an effect at one sample station, which is discussed subsequently. Tables 5-12 and 5-13 summarize the calibrated kinetic coefficients and pollutant concentrations for the URDP model, respectively. Parameter Units Value CBOD - CSO Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.75 Settling Velocity m/day 2.0 CBOD - Storm Water Sources Deoxygenation Rate day-1 0.5 Particulate Fraction -- 0.25 Settling Velocity m/day 0.5 Organic Nitrogen Mineralization Rate day-1 0.01 Particulate Fraction -- 0.25 Settling Velocity m/day 0.3 Ammonia Nitrification Rate day-1 0.2 E. coli - CSO Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.75 Settling Velocity m/day 2.0 E. coli - Storm Water Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.25 Settling Velocity m/day 0.5 E. coli - Upstream Sources Decay Rate day-1 1.0 Particulate Fraction -- 0.25 Settling Velocity m/day 0.3 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-55 February 2011 Segment Specific Parameters Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) Segment ID SOD (g/m2/d) Chl-a (mg/L) 1 2.5 240 12 3.0 144 23 0.5 240 2 2.5 240 13 3.0 144 24 0.5 240 3 2.5 240 14 3.0 144 25 0.5 240 4 2.5 240 15 3.0 144 26 0.5 240 5 2.5 240 16 3.0 144 27 0.5 240 6 2.5 144 17 2.5 240 28 0.5 240 7 2.5 144 18 2.5 240 29 0.5 240 8 2.5 144 19 0.5 240 30 0.5 240 9 2.5 144 20 0.5 240 31 0.5 240 10 2.5 144 21 0.5 240 11 3.0 144 22 1.5 240 Table 5-12 Kinetic Parameters for the Upper River Des Peres EUTRO Model CSO Storm Water Parameter Units 1st hour 2nd hour Balance 1st hour 2nd hour Balance Ammonia mg/L 1.4 1.4 1.4 0.7 0.7 0.05 Nitrate mg/L 0.5 0.5 0.5 0.7 0.7 0.05 Organic Nitrogen mg/L 5.2 5.2 5.2 3.0 3.0 1.0 CBOD5 mg/L 30 30 30 25 25 2.0 Dissolved Oxygen mg/L 3.0 3.0 1.0 4.0 4.0 6.0 E. coli #/100 mL 500,000 200,000 200,000 150,000 100,000 10,000 Table 5-13 CSO and Storm Water Pollutant Concentrations for the Upper River Des Peres 5.8.1 Calibration Event: September 2008 In all the calibration comparison plots, the first four panels are on the main stem of the URDP, arranged from upstream to downstream. The last two panels are from sample stations on two branches of the URDP. The calibration results for DO are shown in Figure 5-42. Although there is not much of an observed sag in DO over time, the diurnal pattern predicted by the model actually hits the sample values quite closely. This is also seen on the branches (the Etzel site on the Pagedale branch only yielded three samples before drying up after about 30 hours). The revised model also does a reasonable job of reproducing the bacteria data, shown in Figure 5-43. The nitrogen parameters (Figures 5-44 through 5-46) tell a similar story as for the other receiving waters. The CSO and stormwater concentrations of ammonia and organic nitrogen lead to brief spikes during wet weather that are not picked up in the sampling; however, use of lower pollutant concentrations is not justified in this case to avoid potentially underestimating water quality impacts in the control alternative evaluations. The same can be said for the CBOD5 concentrations seen in Figure 5-47; note that many of the sample values were less than detection. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-56 February 2011 Figure 5-42 Upper River Des Peres: Dissolved Oxygen Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-57 February 2011 Figure 5-43 Upper River Des Peres: E. coli Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-58 February 2011 Figure 5-44 Upper River Des Peres: Ammonia Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-59 February 2011 Figure 5-45 Upper River Des Peres: Organic Nitrogen Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-60 February 2011 Figure 5-46 Upper River Des Peres: Nitrate Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-61 February 2011 Figure 5-47 Upper River Des Peres: CBOD5 Calibration, September 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-62 February 2011 5.8.2 Validation Event: June 2008 Some validation of the URDP model is provided by the data from the June 2008 event, and the comparisons are shown in Figures 5-48 through 5-53. In these figures, the upstream-most sample location is at Woodson Road, which is about 400 feet downstream from the upstream boundary of the model. This location dried up after two samples. Note also that a dry weather sewage overflow affected the samples taken at Vernon Road. These issues notwithstanding, the agreement between model and data for DO is quite good, and is also reasonable for E. coli bacteria, especially at North and South Road. Given the overall difficulties in capturing the very wide range of flows seen in a system like the URDP, the model results are suitable for characterizing the water quality impacts of wet weather on an annual average basis. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-63 February 2011 Figure 5-48 Upper River Des Peres: Dissolved Oxygen Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-64 February 2011 Figure 5-49 Upper River Des Peres: E. coli Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-65 February 2011 Figure 5-50 Upper River Des Peres: Ammonia Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-66 February 2011 Figure 5-51 Upper River Des Peres: Organic Nitrogen Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-67 February 2011 Figure 5-52 Upper River Des Peres: Nitrate Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-68 February 2011 Figure 5-53 Upper River Des Peres: CBOD5 Validation, June 2008 Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-69 February 2011 5.9 Calibration of Photosynthesis and Respiration Process to Continuous Dissolved Oxygen Data Continuous DO data were used to calibrate the parameters used in the photosynthesis and respiration (PR) routine that was added to the EUTRO model to simulate diurnal variations in DO. The calibrated parameter values are shown in previous tables; this section presents some graphic comparisons and provides a brief discussion. A comparison of modeled DO to sonde data from the South Broadway (Lower River Des Peres) location is shown in Figure 5-54. This period of data was chosen because it includes a backwater event beginning around August 25 and extending through September 9; backwater is represented on the figure by including downstream stage. The model reproduces the diurnal variation in DO for some of the days in the period, before the backwater event, although other days are attenuated. This results from the computation of the solar radiation input from cloud cover data at Lambert airport, which will not always reflect actual radiation input at specific locations on the LRDP. The model also reproduces the general depression of DO that occurs with the onset of the backwater condition. For several days during the backwater event, increases are seen in the sonde data that are not reproduced by the model. The observed DO spikes may result from wet weather inputs, or other disturbances that mix oxygen from a surface layer to the sonde location at the bottom. The model, in contrast, is completely mixed in the vertical and while the wet weather flows are included, their magnitude is not large enough relative to the entire (completely mixed) volume of this model to significantly influence the DO. As the backwater recedes and flow is restored to the segment, along with a reduction in the light extinction, photosynthesis returns. The chlorophyll-a concentration parameters values for the LRDP are shown, on a per-model segment basis, in Table 5-8. The values range from 60 to 300 mg/L, and were selected to achieve the amplitude of diurnal variations observed in the continuous monitoring data. These calibrated values appear large if compared to typical measurements in riverine systems, but this is largely because the PR formulation assumes that the algal biomass is suspended throughout the water column, and does not explicitly consider attached algae. In the case of the LRDP, attached algae likely play a significant role, especially in lower reaches where the substrate includes considerable amounts of coarse materials, such as broken concrete. To account for this, the model chlorophyll-a parameter must be increased beyond values that would be measured in the water column alone. This approximation is acceptable because the intent of the model is to capture diurnal variations in DO sufficiently to determine daily minimum values. Figure 5-54 Comparison of Model to Sonde Data at South Broadway Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-70 February 2011 Figure 5-55 compares modeled DO to sonde data at Morgan Ford Road at a later period, after the sonde was moved from South Broadway. This period includes the November 2007 wet weather event. Here the diurnal pattern is matched more consistently, and the wet weather response is also realistic. Figure 5-55 Comparison of Model to Sonde Data at Morgan Ford Road Sondes were also placed on Maline Creek to evaluate diurnal DO patterns. Figure 5-56 compares modeled DO to sonde data at Riverview Road for a period of time that included one large wet weather event. There is some variability, in part from solar radiation approximations (as discussed previously) and also, presumably, from water clarity which was not measured directly, but assumed to vary with discharge. The moderate suppression of photosynthesis that occurred during the wet weather event (July 19-20) is reproduced to some extent by the model. As shown in Table 5-10, calibrated chlorophyll-a concentrations vary from 40 to 120 mg/L, a narrower range than for LRDP. This reflects the generally smaller observed amplitudes in diurnal DO variation. Figure 5-56 Comparison of Model to Sonde Data at Riverview Road Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-71 February 2011 Figure 5-57 compares modeled DO to sonde data at Lewis and Clark Boulevard during the November wet weather event. As noted in the calibration discussion (Section 5.7), data from this location is used as an upstream boundary condition and this is the main reason for the close correspondence between the model and the sonde data. It is interesting to note also the agreement between the sonde data and the grab samples taken for the wet weather survey. Figure 5-57 Comparison of Model to Sonde Data at Lewis and Clark Boulevard Figures 5-58 and 5-59 compare modeled DO to sonde data at Purdue Avenue, in the Upper River Des Peres. The first plot is for a period with little rainfall, whereas the second plot represents a wet weather survey event. The amplitude of the diurnal variation is simulated well during dry weather. During the wet weather event, there is more of a discrepancy between the sonde data and the model; interestingly, however, the model more closely matches the grab sample data. Chlorophyll-a concentration values in the model range from 144 to 240 mg/L, with the highest values in the Vinita Park Branch where observed DO concentrations tend to be the highest (see Figures 5-42 and 5-48). Figure 5-58 Comparison of Model to Sonde Data at Purdue Avenue during Dry Weather Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 5. RECEIVING STREAM CHARACTERIZATION, MONITORING AND MODELING Page 5-72 February 2011 Figure 5-59 Comparison of Model to Sonde Data at Purdue Avenue during Wet Weather Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-1 February 2011 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY This section presents estimated pollutant loads and their predicted impact on water quality in the Mississippi River and its tributaries, which serve as a baseline condition for comparison to the selected control alternative. Pollutant loads are based on a “typical year,” and are determined by application of event mean concentrations (EMCs) to the overflow volumes predicted by the collection system model. In the case of the tributaries, the impact of these pollutant loads is determined by application of the calibrated water quality models. Mississippi River impacts were not modeled, however, because the Water Quality Study Report (LimnoTech, 2006) concluded that there were no parameters of concern that required modeling to assess. The baseline condition for the Mississippi River is considered to be the same as described in the Existing Conditions section of this report. 6.1 Determination of Typical Year The typical year was initially selected based on rainfall characteristics, with the focus on collection system behavior. A 57-year history (1949 to 2005) of hourly rainfall data for Lambert-St. Louis International Airport was analyzed and a variety of statistical measures were determined, including total number of precipitation events, total annual precipitation, average event precipitation, average event rainfall intensity, total rainfall duration, average event duration, and average time between events. Individual years’ data were then examined to identify the year in which precipitation patterns best matched the “typical” or average of the 57 year history. The distribution of individual-event rainfall depths in the selected year was also compared to the historical distribution to verify that the rainfall record in the selected year was not overly influenced by abnormal events. Based on this analysis, the year 2000 was selected for use in typical year simulations; section 3.1.4.4 presents a comparison between the rainfall characteristics of the typical year and the long-term average. During development of the water quality models it became apparent that the presence of high backwater stage had important effects on water quality, and it was desired to confirm that the downstream stage characteristics of the typical year were, in fact, representative of typical conditions. The question is not trivial because the stage in the Mississippi River at St. Louis is not strongly tied to local rainfall, owing to the river’s large drainage area. Stage data from USGS gage 07010000 (St. Louis at Market St.) was obtained covering 1933 through 2007 and various analyses were conducted to determine what constituted typical conditions. A seasonal pattern emerges when long-term monthly averages are calculated, consisting of higher spring levels followed by lower levels from late summer through fall. However, individual years seldom exhibit this exact pattern, so it is impractical to define “typicalness” based on a resemblance to long- term averages. Instead, the occurrence of backwater events was taken to be analogous to flood events, so that a probability of exceedance could be assigned to the backwater conditions of year 2000. For the purposes of this analysis, a backwater event was defined as a period of two or more consecutive days over which the Mississippi River stage exceeded a specified level. For each year, the durations of all backwater events relative to a given stage level were computed, and the longest duration was taken to be the maximum event, analogous to the peak annual flood discharge. The maximum events were then ranked, and return probabilities computed as is typically done for flood frequencies. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-2 February 2011 Table 6-1 summarizes the longest backwater event from year 2000, and shows its probability of exceedance; this information is shown along with the probability curves in Figure 6-1. For example, during the longest backwater event of year 2000 the stage at the Market Street gage exceeded 15 feet for 38 consecutive days; the probability of an event equaling or exceeding this in any given year is 47%. At higher stages, the duration is shorter, and the probability of occurrence is generally higher. From this perspective it is asserted that the backwater conditions of year 2000 are not atypical, because there is at least a 50% chance that they would be equaled or exceeded in any given year. Note also that the backwater events used to develop the probabilities in Table 6-1 were limited to the months of May through October, which were considered to be more critical times with respect to water quality. If the analysis considers the entire year, the probabilities associated with the year 2000 event is actually even higher. Stage Level (feet) Duration (days) Probability of Exceedance 15 38 47% 18 22 53% 20 13 58% 21 11 57% 22 10 54% 23 6 57% Table 6-1 Probabilities Associated with Maximum Year 2000 Backwater Event Figure 6-1 Assessment of Probability of the Year 2000 Backwater Event Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-3 February 2011 6.2 Lower and Middle River Des Peres The calibrated FEQ/EUTRO model of the Lower and Middle River Des Peres was used to evaluate the impacts of pollutant loads on water quality for the typical year. Table 6-2 summarizes the total annual volumes and pollutant loads included in the model, divided among CSO, stormwater and base flow sources. CSO loads are derived from flows provided by the XP-SWMM model of the collection system (see Section 4). Stormwater loads were derived from flows provided by the SWMM5 model of the watershed (see Section 5). Base flow loads represent the dry weather contribution from Deer Creek and Gravois Creek to the River Des Peres. Note that because sanitary sewer overflows (SSOs) were not explicitly modeled, their potential presence was covered by using elevated levels of bacteria for the stormwater sources; that is, the stormwater loads reflect the potential contributions of SSOs. Note also that for the purposes of calculating loads, all discharge from the Forest Park Tubes (Lemay Outfall 063) was assumed to be CSO, although this discharge does include a component of stormwater from the Upper River Des Peres. Table 6-2 shows that the volume of stormwater, in the typical year, is roughly two-thirds again as large as that of CSO, whereas the stormwater load is generally less than half the CSO load. This is a result of the different pollutant concentrations used for the two sources. The base flow loads are trivial by comparison, and are included for completeness only. Source Parameter Units CSO Stormwater Base Flow Volume MG 6,149 10,470 2,314 CBOD5 tons 609 378 19.3 Ammonia N tons 33.0 10.5 0.96 Organic N tons 123.0 43.7 4.82 E. coli million counts 5.61 × 1010 1.45 × 1010 1.75 ×107 Table 6-2 Modeled Pollutant Loads to River Des Peres in Typical Year Predicted water quality is represented by assessing compliance with applicable water quality standards for the pollutants of concern. For DO, comparisons are made both with Missouri’s daily minimum criterion of 5 mg/L, and with USEPA’s National Recommended Criteria of 4 mg/L as a daily minimum and 5 mg/L as a daily average. The compliance assessment involves calculating the average and minimum values for each day of the year, and determining a percent time in compliance; that is, if there are no exceedances, the percent time in compliance is 100%. For E. coli bacteria, the water quality standard (based on a recreational use designation) is expressed as the geometric mean for the recreational season, and this value is calculated from the model output. For ammonia, 30-day average concentrations are calculated and compared to the chronic criterion, while daily maximum concentrations are compared to the acute criterion. Note that the ammonia criteria are temperature and pH specific; the seasonally-varying model temperature was used, along with a pH value that represented the 85th percentile of observed values. A bounding assessment of the effect of CSOs was obtained by running the same typical year scenario with all CSO inputs removed. With the exception of the upstream model boundary at the Forest Park Tubes outlet (Lemay Outfall 063), all CSO flows and pollutant loads were set to zero, and not replaced with any stormwater loads (which is likely a conservative assumption). At the upstream boundary, a no-CSO discharge was developed from the output of the Upper River Des Peres model, also with CSO inputs removed. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-4 February 2011 Figures 6-2 and 6-3 show the percent time of compliance with the average and minimum DO criteria, respectively; two pairs of lines are shown in Figure 6-3, corresponding to the two different minimum criteria. The plots are limited to the lower reach of the River Des Peres below Deer Creek, because the middle reach (above Deer Creek) is unclassified. Two conclusions can be readily made from these results: 1) that exceedances of both acute and chronic criteria occur regularly during a typical year, and 2) that removal of CSOs does not greatly increase the time of compliance (although the difference is slightly greater when the Federal value of 4 mg/L is used as a minimum criterion, versus the State value of 5 mg/L). Most exceedances occur during wet weather, but some occur during dry weather as well, primarily during periods of backwater influence. In certain reaches of the river, dry weather exceedances of the minimum criterion as a result of wide diurnal variations are not infrequent (see Figure 5-54), and are not changed by removal of wet weather loads. Exceedances of both criteria in backwater-affected reaches results from a combination of wet weather loads and sediment oxygen demand (SOD). The long-term effects of complete CSO removal on SOD and PR were not simulated by the model. Figure 6-2 Typical Year Average DO Compliance for Lower River Des Peres (Daily Average of 5 mg/L) Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-5 February 2011 Figure 6-3 Typical Year Minimum DO Compliance for Lower River Des Peres Figure 6-4 shows the geometric mean E. coli concentration from the river mouth upstream to the confluence with Deer Creek, calculated for the recreational season (April 1 through October 31); included for comparison is the secondary contact recreation (SCR) criterion of 1,134 #/100 mL. Compliance with this criterion in the typical year is not an issue, and complete removal of CSOs has a relatively minor effect. This is largely because wet weather effects are highly transient, and dry weather conditions prevail most of the time. The difference between dry and wet weather conditions is shown in Figure 6-5, which compares a dry weather profile to a peak condition from the typical year simulation. The instantaneous bacteria levels are high, and the difference between the existing conditions and the no-CSO simulation is readily apparent. Peak bacteria levels from stormwater alone, while lower than CSO-affected levels, are still high enough to discourage contact recreation. The typical year results were also evaluated for compliance with acute and chronic concentration criteria for ammonia. Both criteria depend on pH, and the chronic criterion is also dependent on temperature. The criteria were calculated using a pH value of 8.3, which represents the 85th percentile of observed values in the receiving waters; temperature (where applicable) was taken from the model input values. The evaluation showed 100% compliance with both the acute criteria (based on daily maximum concentrations) and the chronic criteria (based on 30-day average concentrations). The results are not depicted here because the 100% compliance situation is identical both with and without CSOs. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-6 February 2011 Figure 6-4 Typical Recreation Season Geometric Mean E. coli for Lower River Des Peres Figure 6-5 Comparison of Peak Wet Weather and Dry Weather E. coli Concentration Profiles for the Lower River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-7 February 2011 6.3 Maline Creek A similar approach was used to evaluate the impacts of CSO loads on Maline Creek in a typical year. Table 6-3 lists the total annual pollutant loads, divided among CSO, stormwater and base flow sources. The total CSO volume is much smaller, relative to other sources, than in the River Des Peres. CSO impacts can be expected to be small as well. Figures 6-6 and 6-7 show the percent time of compliance with the average and minimum DO criteria, respectively. Figure 6-8 shows the recreational season geometric mean E. coli bacteria concentration. In all three figures, the influence of CSOs is difficult to perceive because of their small volume relative to upstream and stormwater sources. The approach to CSO control on Maline Creek, therefore, is not predicated on water quality in a direct sense. Compliance with ammonia criteria was also evaluated for Maline Creek and, like with the Lower River Des Peres, compliance with the criteria was predicted to occur 100% of the time, both with and without CSOs. Source Parameter Units CSO Stormwater Base Flow Volume MG 151 2,740 420 CBOD5 tons 19.9 49.1 3.50 Ammonia N tons 0.94 3.47 0.087 Organic N tons 2.02 2.31 0.175 E. coli million counts 1.57 × 109 1.21 × 109 1.59 ×106 Table 6-3 Modeled Pollutant Loads to Maline Creek in Typical Year Figure 6-6 Typical Year Average DO Compliance for Maline Creek (Daily Average of 5 mg/L) Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-8 February 2011 Figure 6-7 Typical Year Minimum DO Compliance for Maline Creek Figure 6-8 Typical Recreation Season Geometric Mean E. coli for Maline Creek Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-9 February 2011 6.4 Upper River Des Peres Total annual pollutant loads to the Upper River Des Peres are summarized in Table 6-4. As with the other receiving waters, the CSO loads were derived from collection system model output and the stormwater loads were derived from watershed model output. Base flow represents the upstream end of the three branches modeled: the main stem, the Vinita Park branch, and the Pagedale branch. Like the Lower River Des Peres, the CSO volume is about half the stormwater volume, but the pollutant loads are roughly double. Both are much smaller relative to base flow, however. Source Parameter Units CSO Stormwater Base Flow Volume MG 527 1,107 189 CBOD5 tons 65.3 33.1 1.57 Ammonia N tons 3.05 1.02 0.039 Organic N tons 11.3 5.76 0.079 E. coli million counts 5.28 × 109 1.10 × 109 7.15 ×105 Table 6-4 Modeled Pollutant Loads to Upper River Des Peres in Typical Year Figures 6-9 through 6-12 depict the compliance evaluation results for the Upper River Des Peres and its branches. There are multiple lines on these figures that represent the multiple branches in the model. The longest line represents the main stem, the shortest line toward the left side represents the Vinita Park Branch, and the shorter line toward the right side represents the Pagedale Branch. Figures 6-9 and 6-10 show the percent time of compliance with the average and minimum DO criteria, respectively. It is notable that the State minimum criterion of 5 mg/L is met only around 70% of the time for much of the river, whereas the Federal minimum of 4 mg/L is met more often. An average daily concentration of at least 5 mg/L is maintained nearly all the time. Differences between attainment of minimum and average criteria are largely the result of PR-related diurnal variations, which can be seen in the sonde data in depicted Figure 5-58. The moderate improvement in compliance that is seen when CSOs are eliminated, however, suggests that on some occasions the stream flow is dominated by CSO flows, with DO levels below the minimum, long enough to register a minimum of less than either criterion but not long enough to drive the average below 5 mg/L. Note that analysis of model output will always pick up these minima even when stream sampling does not. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-10 February 2011 Figure 6-9 Typical Year Average DO Compliance for Upper River Des Peres (Daily Average of 5 mg/L) Figure 6-10 Typical Year Minimum DO Compliance for Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-11 February 2011 Figure 6-11 shows the geometric mean E. coli concentration for the three branches of the Upper River Des Peres modeled, calculated for the recreational season (April 1 through October 31); these results are included for illustrative purposes, as it is noted that the Upper River Des Peres is not classified and bacteria criteria do not apply. The line showing the results for the no-CSOs simulation demonstrates that the influence of CSOs begins to be noticeable downstream of North & South Road, and increases somewhat by the time the river goes underground. The difference between dry and wet weather conditions is shown in Figure 6-12, which compares a dry weather profile to a peak condition from the typical year simulation. As in the Lower River Des Peres, the instantaneous bacteria levels are high, and the difference between the existing conditions and the no-CSO simulation is also readily apparent. Peak bacteria levels from stormwater alone, while lower than CSO-affected levels, are still high enough to discourage contact recreation. Compliance with ammonia criteria was evaluated for the Upper River Des Peres in the same manner as for the other receiving streams. Like the others, the standards were met 100% of the time during the typical year. Figure 6-11 Typical Recreation Season Geometric Mean E. coli for Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 6. ESTIMATED POLLUTANT LOADINGS AND PREDICTED WATER QUALITY Page 6-12 February 2011 Figure 6-12 Comparison of Peak Wet Weather and Dry Weather E. coli Concentration Profiles for the Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-1 February 2011 7. CSO CONTROL OPTIONS AND SCREENING 7.1 Introduction This section describes how MSD evaluated a wide range of over 70 CSO control technologies, taking into consideration the site-specific nature of its CSOs and receiving waters, and its established CSO control goals. The technologies were screened to determine the feasibility and applicability of each to the unique characteristics of MSD’s combined sewer system. Feasible CSO control technologies were then assembled into 55 Integrated Control Alternatives specific to each receiving water. This process of technology screening, and assembly of feasible technologies into alternatives, is referred to in this report as the “Level 1” screening process. This section also describes how the 55 Integrated Control Alternatives identified during the Level 1 screening process were then further screened to develop a short list of 12 alternatives, representing the most feasible and cost effective alternatives, for further analysis. This process of selecting the most feasible and cost-effective alternatives is referred to in this report as the “Level 2” screening process. SOURCE CONTROL TECHNOLOGIES TREATMENT TECHNOLOGIES STORAGE TECHNOLOGIES COLLECTION SYSTEM CONTROLS LEVEL 1 SCREENING INTEGRATED CONTROL ALTERNATIVES SPECIFIC TO MSD’S SYSTEM AND RECEIVING WATERS LEVEL 2 SCREENING FEASIBLE AND COST-EFFECTIVE INTEGRATED CONTROL ALTERNATIVES 70+ TECHNOLOGIES 55 ALTERNATIVES 12 ALTERNATIVES SOURCE CONTROL TECHNOLOGIES TREATMENT TECHNOLOGIES STORAGE TECHNOLOGIES COLLECTION SYSTEM CONTROLS LEVEL 1 SCREENING INTEGRATED CONTROL ALTERNATIVES SPECIFIC TO MSD’S SYSTEM AND RECEIVING WATERS LEVEL 2 SCREENING FEASIBLE AND COST-EFFECTIVE INTEGRATED CONTROL ALTERNATIVES 70+ TECHNOLOGIES 55 ALTERNATIVES 12 ALTERNATIVES Figure 7-1 Level 1 and Level 2 Screening Process 7.2 CSO Control Goals The primary goals to be accomplished through the implementation of CSO controls are to meet the technology-based requirements of the Clean Water Act and to meet applicable water quality standards. As noted in Section 3.3, many of the receiving waters in MSD’s service area have undergone and are still undergoing review by the Missouri Department of Natural Resources and the U.S. EPA to determine appropriate uses, thereby affecting applicable water quality standards. Missouri’s numeric water quality standards likewise have undergone significant revision during the LTCP planning process. In meeting water quality standards, MSD desires to 1) reduce bacteria loads to meet appropriate recreational uses, and 2) reduce the discharge of oxygen demanding pollutants to the backwater impacted streams – Maline Creek and Lower River Des Peres – to meet aquatic life uses. Secondary water-quality-related CSO control goals include the following: • Solids and floatables reduction • CSO volume reduction Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-2 February 2011 • CSO frequency reduction • CSO duration reduction In implementing its CSO controls, MSD also desires to: • keep user rates affordable, • utilize green infrastructure where feasible, • maximize the use/reuse of existing infrastructure, • minimize operational and maintenance needs, • provide dual purpose facilities (e.g., skate park atop CSO storage tank) where possible, and • coordinate CSO controls with flood controls. It is with these goals in mind that the screening of available CSO control technologies was performed. 7.3 Level 1 Screening 7.3.1 Technology Screening Over 70 available CSO control technologies were identified and evaluated by utilizing a Technologies Matrix. The Technologies Matrix describes each available control technology, its associated environmental impacts and improvements, and the implementation and operational factors critical to each technology. The Technologies Matrix is presented in Appendix H. Each of the CSO control technologies that was evaluated can be classified under one of four categories described in EPA’s Combined Sewer Overflows: Guidance for Long-Term Control Plan: • Source Control Technologies – those technologies that affect the quantity or quality of runoff prior to entering the collection system. • Collection System Controls – those technologies that affect CSO flows and loads once the runoff has entered the collection system. • Storage Technologies – those technologies that provide for storage of flows from the collection system for subsequent treatment after the storm is over and conveyance and treatment capacity have been restored. • Treatment Technologies – those technologies that provide for either local (at the CSO) or centralized treatment of CSO flows to reduce the pollutant loading to receiving waters. After reviewing the matrix of control technologies, controls specifically applicable/feasible for MSD were identified and compiled, as identified in the Technology Screening Matrix in Table 7-1 below. The Technology Screening Matrix is a tool used to evaluate each technology or control as it may pertain to MSD’s unique combined sewer system. The technology screening matrix also allows consideration of each control technology as it pertains to each of MSD’s receiving water segments, thus laying the framework for the Integrated Control Alternatives to be developed. TECHNOLOGIES Eliminate Consider Common to All REASONS/NOTES COLLECTION SYSTEM CONTROLS Infiltration/Inflow Reduction X Only consider for large inflow sources (e.g. prevent receiving waters and high groundwater from entering combined sewers). CSO Diversion Structure Improvement Program X Increasing diversion capacity has potential in Bissell and Maline systems. Sewer System Cleaning/ Flushing X Ongoing program - small sewers cleaned on 7-year cycle. Sewer/CSO Diversion Structure Maintenance X Ongoing program. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-3 February 2011 TECHNOLOGIES Eliminate Consider Common to All REASONS/NOTES Outfall Maintenance Program X Ongoing program. House Lateral Repairs X Need to evaluate I/I, especially in sanitary sewers to determine if house lateral repairs would be of benefit Real Time Control X Consider inline storage in the two 29-ft diameter horseshoes in the Middle River Des Peres. The 1999 CSO LTCP identified the use of Macklind Pump Station to transfer wet weather flow. Sewer Separation X Consider eliminating CSOs for small tributaries. Separation of street inlets only (partial separation) can also be considered. Industrial Source Separation X Anheuser-Busch and Mallinckrodt (Tyco) are already disconnected from combined sewer system. Outfall Consolidation/ Relocation X Consider for small tributaries. STORAGE TECHNOLOGIES Storage Before Sewer Industrial Discharge Detention X Consider having industries detain process and storm water discharges during wet weather. Residential and Commercial Detention X MSD is imposing requirements for re-development to detain discharge. Wet Storage Ponds X Consider where space is available. Dry Storage Ponds X Consider where space is available. Storage in Sewer System In-line Storage – Interceptor X The interceptors are used for conveyance. No additional capacity for storage. In-line Storage – Trunk Sewer X Recently evaluated, concerned with basement backups. Concerned about potential damage to old brick sewers from repetitive cycles of storage/emptying. Off-Line Storage Tunnels in Rock or Soil X MSD has installed small diameter conveyance tunnels. Off-line Covered Storage Basins/Sedimentation Tanks X Interested in dual purpose tanks. There is potential for buried tanks with park on top along River Des Peres. Off-line Open Storage Basins/Sedimentation Tanks X Potential sites along Maline Creek and Mississippi River. TREATMENT TECHNOLOGIES At CSO Facility Storage Tank - Sedimentation X Consider locating immediately downstream of the two 29-ft diameter horseshoe tunnels in the Middle River Des Peres. Clarification - Solids Contact X Would require screening and disinfection facilities and large footprint. Enhanced High Rate Clarification X Achieves 85% solids removal and requires a small footprint. Chemical and ballast handling is a concern. Recommend that these units be manned during operation. Ballast generates extra solids. Consider for treating discharges from two 29-ft horseshoes in-line at Middle River Des Peres. Consider in conjunction with storage and Macklind Pump Station. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-4 February 2011 TECHNOLOGIES Eliminate Consider Common to All REASONS/NOTES Vortex Separation X Removes large solids. Not efficient at removing small solids. Good chlorine contact chamber. Macklind Storm King (100 MGD) was considered in 1999 LTCP. Land is at a premium, but there is a Defense Mapping space adjacent to the Lemay WWTP. Compressed Media Filtration X High Cost, larger footprint than Enhanced High Rate Clarification. Requires grit and large solids removal upstream of filters. Columbus GA is the only one. Biological Treatment X Not feasible for intermittent flow. Chemical Disinfection (Cl2, Br2, ClO2) & Dechlorination X Can adjust to variable conditions - solids and flow rates. UV Disinfection X Effective for disinfecting CSOs when suspended solids are below 30 mg/l. Mechanical Screens X Weir mounted screens in CSO diversion structures have been effective for control of floatables. Over/under Baffles X Preference for over/under baffles when screenings drop into the flow to the WWTP. Locate o/u baffles upstream of the Mississippi River Outfalls. Effective floatable control technology. Netting Systems X Labor intensive. Feasible for River Des Peres and Maline Creek. Lots of floatables from SSOs and storm water runoff. Not feasible at the outfall discharges to the Mississippi River due to limited access and submerged outfalls. At Existing Treatment Facility Maximize Flow through Treatment Plant X X Flows must be pumped up to Bissell Plant. Inactive activated sludge tanks could be used for storage or treatment of CSO flows. Screening X Consider using in conjunction with treatment and disinfection. Conventional Clarification X Would require using in conjunction with grit removal, storage tanks, and disinfection. Space is not available. High Rate Clarification X Could be used in conjunction with biological treatment at WWTPs. Peak shaving device. Vortex Separation X Removes large solids. Not efficient at removing small solids. Good chlorine contact chamber. Macklind Storm King (100 MGD) was considered in 1999 LTCP. Land is at a premium, but there is a Defense Mapping space adjacent to the Lemay WWTP. Compressed Media Filtration X Expensive. Deep bed Filtration X Expensive. Biological Treatment X Expensive. Chemical Disinfection (Cl2, Br2, ClO2) & Dechlorination X Consider using in conjunction with additional treatment at WWTPs. UV Disinfection X Consider using in conjunction with additional treatment at WWTPs. Equalization Open Storage X Consider using existing inactive aeration tanks at Bissell. Could build new storage tanks at or adjacent to Lemay. Equalization Closed Storage X Consider using vertical storage drop shafts in any new tunnel. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-5 February 2011 TECHNOLOGIES Eliminate Consider Common to All REASONS/NOTES SOURCE CONTROL TECHNOLOGIES Storm water Management Wet Storage Ponds X Potential issue with attracting people to ponds. Dry Storage Ponds X Along flood wall, at north end of Baden (swale). Wetlands Treatment X Only consider in Lower River Des Peres. Sump Pump Disconnect Program X Limited enforcement authority by MSD. Benefit needs to be evaluated before a program is initiated. Catch Basin Cleaning X Ongoing program. Illicit Connection Control X Ongoing program. Roof Leader Disconnect Program X Consider rain barrels, check ordinance. MSD has a pilot rain barrel program. Leaching Catch Basins (Dry Wells) X Not feasible, clay soils. Swales & Filter Strips X Along River Des Peres. Porous Pavement X In developed areas. Parking Lot Storage X Existing systems combine drainage with CSO relief. Street Storage (Catch Basin Inlet Control) X Consider where feasible. Other Green Solutions X Include with public outreach program Solid Waste Collection/Disposal Illegal Dumping Control X Ongoing program. Solid Waste Program X Ongoing program. Hazardous Waste Collection X Ongoing program. Public Education Catch Basin Stenciling X Ongoing program. Community Cleanup Program X Clean Stream Team, River Des Peres Watershed Coalition, and other neighborhood programs. Recycling Programs X Ongoing program. Animal Waste Management X Ongoing MS4 program. Lawn & Garden Maintenance X Ongoing program. Adopt-a-River X Ongoing program. Warning Signage X Ongoing program. Construction Related Onsite Erosion Control/ New Construction X On-going program. Soil Stabilization Measures X On-going program. Stabilized Construction Entrance X On-going program. Good Housekeeping Industrial Storage/ Loading/Unloading Areas X Ongoing program. Industrial Spill Control X Ongoing program. Street Sweeping Programs X Ongoing program. Ticketing parking violators would create a negative image. Miscellaneous Industrial Pretreatment Program X Ongoing program. Stream bank Stabilization/Restoration X Ongoing program. Septic Tank Improvements X Ongoing program. Table 7-1 Technology Screening Matrix Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-6 February 2011 7.3.2 Development of Integrated Control Alternatives Integrated Control Alternatives were developed for each receiving water segment by selecting control technologies that were deemed to be feasible and applicable, and packaging these technologies into alternatives crafted and adapted to the specifics of the combined sewer system and receiving water segment. Each Integrated Control Alternative consists of one or more of the following components: • Source Control Technologies that were determined to be applicable to all alternatives – these controls include such items as green infrastructure, illicit connection control, stormwater detention for new developments, catch basin cleaning, solids/floatables control, illegal dumping control, hazardous waste collection, good housekeeping, street sweeping, construction erosion and waste control, litter control, industrial pretreatment program, stream teams, community clean-up programs, recycling programs, pet waste management, proper yard waste disposal, and the installation and maintenance of warning signage; • Collection System Technologies that were determined to be applicable to all alternatives – these controls include such items as diversion structure maintenance, outfall maintenance, sewer system cleaning and sewer separation for new developments or redevelopments; • Long-term CSO controls that have already been implemented by MSD or are currently being implemented by MSD that will continue to serve an important long-term role in controlling CSOs; and • New long-term CSO controls necessary to meet the established CSO control goals. The following paragraphs describe in detail the Integrated Control Alternatives that were developed for each receiving water segment. 7.3.3 Maline Creek – Integrated Control Alternatives Fifteen different Integrated Control Alternatives were developed for the four CSOs that discharge to Maline Creek. Figure 7-2 shows the general location of the CSOs and related infrastructure. Each alternative includes the source control technologies and collection system controls identified in Section 7.3.2 as common to all alternatives. Each alternative also includes the following controls that have already been implemented or are currently being implemented in the combined sewer systems tributary to Maline Creek, and in the upstream separate sanitary sewer systems: • Sewer separation of Bissell Point Outfall 053. Outfall 053 is a 24-inch diameter combined sewer with a single sanitary connection from the Riverview Industrial Center. The combined sewer picks up additional storm flow and outfalls as a 42-inch sewer to Maline Creek. MSD has designed and recently completed construction of a sewer separation project to take the sanitary flow directly to the Mississippi River Interceptor and convert the existing combined sewer to a separate storm sewer, and thus eliminate Bissell Point Outfall 053. • Sewer separation of Bissell Point Outfall 060. Outfall 060 is a 24-inch diameter combined sewer with a single sanitary connection from an out-building at the Riverview Industrial Center. MSD has designed and has recently completed construction of a sewer separation project to take the sanitary flow directly to the Maline Trunk Sewer and convert the existing 24-inch sewer to a separate storm sewer, thus eliminating Bissell Point Outfall 060. • Bissell Point Overflow Regulation System. This project was constructed in the late 1980s and early 1990s. As discussed in Section 3.2, this project essentially eliminated the influence of Mississippi River stage on the interception of flows from the Riverview system. Prior to the implementation of this project, all flow in the Riverview system that occurred at river stage 20 and above was diverted to Maline Creek. River stages of 20 feet and higher typically occur about 15 percent of the time, on an average annual basis. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-7 February 2011 • Infiltration and Inflow (I/I) Control in Sanitary Sewer Systems. MSD is currently conducting I/I studies in various areas of the Maline Creek, Spanish Lake and Watkins Creek watersheds. Although the extent of the achievable reduction is currently undefined, I/I reduction should reduce peak flow rates in these separate sanitary sewer systems, potentially allowing for greater capture of wet weather flows from the combined sewer system. Figure 7-2 Maline Creek CSOs Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-8 February 2011 After implementation of the above four controls, two CSOs will remain to Maline Creek: Bissell Point Outfalls 051 and 052. Integrated Control Alternatives were defined that build upon the above controls to address these remaining two CSO outfalls. The Integrated Control Alternatives are summarized in Table 7-2 and described below. Specific CSO Controls Alternative Source Controls Collection System Controls Overflow Regulation System Outfall 051 Outfall 052 Outfall 053 Outfall 060 A X X X existing tunnel express new express sewer sewer separation sewer separation B1 X X X new storage tunnel existing tunnel express sewer separation sewer separation B2 X X X local storage existing tunnel express sewer separation sewer separation B3 X X X local treatment existing tunnel express sewer separation sewer separation B4 X X X sewer separation existing tunnel express sewer separation sewer separation B5 X X X partial separation and local storage existing tunnel express sewer separation sewer separation B6 X X X partial separation and local treatment existing tunnel express sewer separation sewer separation B7 X X X in-sewer storage and local treatment existing tunnel express sewer separation sewer separation C1 X X X local storage local storage sewer separation sewer separation C2 X X X local treatment local storage sewer separation sewer separation C3 X X X sewer separation local storage sewer separation sewer separation C4 X X X partial separation and local storage local storage sewer separation sewer separation C5 X X X partial separation and local treatment local storage sewer separation sewer separation C6 X X X in-sewer storage and local treatment local storage sewer separation sewer separation D X X X local treatment and outfall relocation local storage sewer separation sewer separation Table 7-2 Integrated Control Alternatives – Maline Creek Alternative A – Express Sewer to Control Bissell Point Outfall 052. This alternative includes the construction of an express sewer to convey, by gravity, the separate sanitary sewer flows from the Maline Creek Trunk Sewer (Maline Creek system) and Mississippi River Interceptor (Watkins Creek and Spanish Lake systems) directly to the Bissell Point Treatment Plant. This express sewer would provide relief to the north leg of the existing Bissell Point Interceptor Tunnel, and thereby control overflows from the Maline Drop Shaft (Bissell Point Outfall 052). The existing north leg of the Bissell Point Interceptor Tunnel would be used to convey combined sewer flows from the Riverview system and other downstream combined sewer systems to the Bissell Point Treatment Plant. Without hydraulic modeling of this alternative, it is unknown what “level of control” this would provide at the Riverview outfall to Maline Creek (Bissell Point Outfall 051). Greater levels of control could be provided by regulating the other inflows to the tunnel (at Bissell Point Outfalls 046, 047, 048, 049 and 050 to the Mississippi River). This, however, would increase overflows from these outfalls to the Mississippi River. It is anticipated that this alternative will require additional pumping and treatment capacity at the Bissell Point Treatment Plant due to the increased wet weather flows conveyed by the existing tunnel and new express sewer. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-9 February 2011 Alternative B – Dedicate Existing Tunnel as an Express Sewer to Control Bissell Point Outfall 052. All of the following alternatives include the dedicated use of the north leg of the existing Bissell Point Interceptor Tunnel as an express sewer to convey separate sanitary flows from the Maline Creek Trunk (Maline Creek system) and Mississippi River Interceptor (Watkins Creek and Spanish Lake systems) directly to the Bissell Point Treatment Plant. Bissell Point Outfall 052 would be removed. Wet weather combined sewer flows would be disconnected from the tunnel and managed as described below. Alternative B1: In this alternative, a new CSO storage tunnel would be constructed to control overflows from the Riverview outfall to Maline Creek (Bissell Point Outfall 051) and from the various outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050) located along the existing tunnel route. The new CSO storage tunnel can be sized to provide the desired level of control at Bissell Point Outfall 051. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative B2: This alternative is identical to Alternative B1 except that instead of a CSO storage tunnel, above-grade or below-grade local storage tanks would be built to store CSO flows at the Riverview outfall to Maline Creek (Bissell Point Outfall 051), and at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050). The tanks can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative B3: This alternative is identical to Alternative B1 except that instead of a CSO storage tunnel, local treatment units would be built to treat CSO flows at the Riverview outfall to Maline Creek (Bissell Point Outfall 051), and at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050). The units can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative B4: This alternative is identical to Alternative B1 except that instead of a CSO storage tunnel, complete separation of the combined sewer system would eliminate the need for CSO control at the Riverview outfall to Maline Creek (Bissell Point Outfall 051). CSO control (storage or treatment) would still be required at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050) to at least maintain the present level of service. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative B5: This alternative is identical to Alternative B2 except that flows to the local storage tank at Bissell Point Outfall 051 would be reduced through partial sewer separation, thereby reducing the storage tank size and cost. Partial separation is separation of street inlets to a new storm sewer system. CSO control (storage or treatment) would still be required at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050) to at least maintain the present level of service. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative B6: This alternative is identical to Alternative B3 except that flows to the local treatment unit at the Riverview outfall to Maline Creek (Bissell Point Outfall 051) would be reduced through partial sewer separation. A smaller treatment unit would thus be required. CSO control (storage or treatment) would still be required at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050) to at least maintain the present level of service. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-10 February 2011 Alternative B7: This alternative is identical to Alternative B3 except that flows to the local treatment unit at the Riverview outfall to Maline Creek (Bissell Point Outfall 051) would be reduced by in-sewer storage. A smaller treatment unit would thus be required. CSO control (storage or treatment) would still be required at the various downstream outfalls to the Mississippi River (Bissell Point Outfalls 045, 046, 047, 048, 049 and 050) to at least maintain the present level of service. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C – Local Storage to Control Bissell Point Outfall 052. All of the following alternatives include the use of a local storage tank to control the infrequent overflows from the Maline Drop Shaft (Bissell Point Outfall 052). Wet weather CSOs from Outfall 051 would be controlled as described below. Alternative C1: A new above-grade or below-grade local storage tank would be built to store CSO flows at the Riverview outfall to Maline Creek (Bissell Point Outfall 051). The tank can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C2: This alternative is identical to Alternative C1 except that instead of a CSO storage tank, a local treatment unit would be built to treat CSO flows at the Riverview outfall to Maline Creek (Bissell Point Outfall 051). The treatment unit can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C3: This alternative is identical to Alternative C1 except that instead of CSO storage, complete separation of the combined sewer system would eliminate the need for CSO control at the Riverview outfall to Maline Creek (Bissell Point Outfall 051). It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C4: This alternative is identical to Alternative C1 except that flows to the local storage tank at Bissell Point Outfall 051 would be reduced through partial sewer separation, thereby reducing the required tank size. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C5: This alternative is identical to Alternative C2 except that flows to the local treatment unit at Bissell Point Outfall 051 would be reduced through partial sewer separation, thereby reducing the required treatment unit size. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative C6: This alternative is identical to Alternative C2 except that flows to the local treatment unit at Bissell Point Outfall 051 would be reduced by in-sewer storage, thereby reducing the required treatment unit size. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative. Alternative D – Local Storage/Treatment and Outfall Relocation. This alternative involves a local treatment unit at Bissell Point Outfall 051, relocating Outfall 051 from Maline Creek to the Mississippi River, and installing a storage tank at Bissell Point Outfall 052. 7.3.4 Gingras Creek – Integrated Control Alternatives Seven Integrated Control Alternatives were developed for the single CSO that discharges to Gingras Creek (Bissell Point Outfall 059). Figure 7-3 shows the general location of Outfall 059. Each alternative includes the common source control technologies and collection system controls previously described in Section 7.3.2. It is anticipated that the existing Bissell Point Treatment Plant will be able to handle peak flows resulting from the implementation of each of the alternatives considered. The Integrated Control Alternatives are summarized on Table 7-3 and described below. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-11 February 2011 Figure 7-3 Gingras Creek CSO Alternative Source Controls Collection System Controls Outfall 059 Controls A X X sewer separation B X X outfall relocation C X X local storage D X X local treatment E X X partial separation and local storage F X X partial separation and local treatment G X X partial separation and outfall relocation Table 7-3 Integrated Control Alternatives – Gingras Creek Alternative A – Complete Sewer Separation. This alternative includes the complete separation of this small combined sewer system into separate sanitary and storm sewer systems, thereby eliminating the CSO. This alternative, however, would add additional flow to the downstream sanitary sewer system. Therefore it would require either significant I/I control work to minimize peak wet weather sanitary flows in the separated system, or a sanitary relief sewer downstream of the currently combined area to handle the increased wet weather flows. Note that there are several constructed SSOs along the existing sanitary sewer downstream of the combined area. Alternative B – Outfall Relocation. This alternative involves the relocation of the combined sewer outfall from Gingras Creek to the Gingras Creek Branch of the Baden Trunk Sewer, and the elimination of the existing diversion structure. Gingras Creek was at one time a tributary to Baden Creek. Baden Creek, in the late 19th and early 20th centuries, was mostly converted to a combined sewer, except for a few small upstream tributary creeks. These creeks remained as open channels, draining to what had become a downstream combined sewer system. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-12 February 2011 Gingras Creek is one of the remaining open channel tributaries. This alternative connects the outfall from the pocket of combined sewers directly to the downstream Baden combined sewer system, thereby eliminating the impact of overflows into the short stretch of open creek between the CSO and the Baden Trunk Sewer. Alternative C – Below-Grade Storage. This alternative involves installing a below-grade storage tank to store overflow volumes from the combined sewer system to the desired level of control. It is very unlikely that space exists near the CSO for an above-grade tank. Alternative D – CSO Treatment. This alternative involves installing a small CSO treatment unit to treat overflows to the desired level of control prior to discharge to Gingras Creek. Space limitations may hinder the feasibility of this option. Alternative E – Partial Separation and Below-Grade Storage. This alternative is identical to Alternative C except that flows to the below-grade storage tank would be reduced through partial sewer separation, thereby reducing the required tank size. Alternative F – Partial Separation and CSO Treatment. This alternative is identical to Alternative D except that flows to the CSO treatment unit would be reduced through partial sewer separation, thereby reducing the required treatment unit size. Alternative G – Partial Separation and Outfall Relocation. This alternative is identical to Alternative B except that a smaller sewer would be required to relocate the outfall due to the flow reduction achieved by partial sewer separation. 7.3.5 Mississippi River – Integrated Control Alternatives Eight Integrated Control Alternatives were developed for the 60 CSOs that discharge to the Mississippi River. Figure 7-4 shows the locations of the Mississippi River CSOs and associated infrastructure. Figure 7-4 Mississippi River CSOs Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-13 February 2011 Each alternative includes the common source control technologies and collection system controls previously described in Section 7.3.2. Each alternative also includes the following controls that have already been implemented or are currently being implemented in the combined sewer systems tributary to the Mississippi River: • Separation of Significant Industrial Users. Industrial wastewater from Anheuser-Busch and Mallinckrodt used to discharge directly into MSD’s combined sewer system. During wet weather events, a portion of these industrial wastewaters would overflow to the Mississippi River through MSD’s combined sewer outfalls. During the mid-1990s both of these industrial sources were removed from the combined sewer system. Characterization data at that time indicated these industrial wastewaters accounted for over half the BOD loading to the Bissell Point Treatment Plant. These industrial wastewaters are now conveyed, following pretreatment, directly to the Bissell Point Treatment Plant through the Bissell Point Interceptor Tunnel. • Full Utilization of Excess Primary Treatment Capacity. System characterization efforts in the early 1990s identified the presence of “excess” or unused preliminary and primary treatment capacity at the Bissell Point Treatment Plant. Flow to the treatment plant was limited by the 250 MGD capacity of its secondary treatment units. The preliminary and primary treatment units potentially could handle 350 MGD flow, if certain improvements to the plant were made. A project was constructed in the mid-1990s to allow greater flows through the preliminary and primary portions of the plant and to blend the primary effluent with secondary effluent prior to discharge. The Bissell Point Treatment Plant can now treat flows up to 350 MGD through preliminary and primary treatment and up to 250 MGD through secondary treatment. • Maximization of Flow Pumping to the Bissell Point Treatment Plant. The Bissell Point Pump Station that feeds all flow to the treatment plant basically operates in a level-control mode during dry weather and a flow-control mode in wet weather. Based on the results of combined sewer system hydraulic modeling, improvements in the pump controls were made during 2006 that resulted in a quicker changeover to flow-control mode during wet weather operations and maintenance of the flow-control mode for a longer period of time during wet weather. This has allowed greater volumes of wet weather flow to be treated at the plant. • Overflow Regulation System. The Bissell Point Overflow Regulation System was constructed in the late 1980s and early 1990s. It essentially eliminated the influence of Mississippi River stage on the interception of flows from the various combined sewers tributary to the Mississippi River. Prior to the implementation of this system, much of the flow that occurred at river stage 20 and above was diverted to the Mississippi River. River stages of 20 feet and higher typically occur about 15 percent of the time. A similar project was implemented in the late-1990s on three outfalls to the Mississippi River in the Lemay system. Those three outfalls discharge to the Mississippi River, just upstream of the River Des Peres. • Sewer Separation for Bissell Point Outfall 055. Bissell Point Outfall 055 is a small 24 inch combined sewer serving a City of St. Louis housing development of 17 homes. All of the roof drains from the homes are connected to the sewer system. Additional storm flow enters the sewer from two downstream catch basins and through deteriorated sewers. MSD has designed and has recently completed construction of a sewer separation project to remove the roof drainage and separate the sewer systems, thereby eliminating this CSO. All of MSD’s CSOs discharge to the Mississippi River, either directly or by way of tributary streams. Therefore, the benefits (e.g., overflow volume or pollutant load reduction) associated with CSO control instituted anywhere along the upstream tributary streams will also apply to the Mississippi River. All integrated CSO control alternatives for the 60 CSOs on the Mississippi River therefore should consider the costs and benefits associated with controls implemented on CSOs to the tributary streams (e.g., Maline Creek and the River Des Peres) – both the controls already implemented and the controls proposed under the LTCP. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-14 February 2011 The integrated control alternatives described below all include the above-listed items as a baseline. The concept used in developing the integrated alternatives was to first systematically build on this baseline by adding controls that involve enhancements to the existing infrastructure (e.g., increased diversion structure capacities, treatment plant expansion). While it was determined that these enhancements will allow increasing degrees of flow and pollutant capture, they do not allow achievement of high levels of control (i.e., 0, 1 to 3, 4 to 7, or 8 to 12 overflows per year). Therefore, a final group of eight integrated alternatives was developed to allow sizing to various levels of control, including those mentioned above. The integrated control alternatives are summarized in Table 7-4 and described below. Specific CSO Controls Alternative Source Controls Collection System Controls Existing Controls1 Controls on Tributary Streams Outfall 055Separation Bissell Point Outfalls Lemay Outfalls North of RDP Lemay Outfalls South of RDP A1 X X X X X tunnel storage tunnel storage local storage A2 X X X X X tunnel storage local storage local storage A3 X X X X X tunnel storage local treatment local treatment A4 X X X X X tunnel storage tunnel storage tunnel storage A5 X X X X X tunnel storage sewer separation sewer separation B X X X X X local storage local storage local storage C X X X X X local treatment local treatment local treatment D X X X X X sewer separation sewer separation sewer separation 1 Existing controls include industrial waste separations, Bissell Point Overflow Regulation System, and flow maximization to the treatment plant. Table 7-4 Integrated Control Alternatives – Mississippi River Alternative A – CSO Tunnel Storage This alternative consists of the baseline controls plus the addition of a tunnel to store CSO flows from the various Mississippi River outfalls. The tunnel and control structures can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative, although an analysis of storage volume vs. treatment capacity may be required. Five variations of this alternative were developed. The variations were developed to explore the cost effectiveness of extending the tunnel southward to address the relatively smaller CSOs in the Lemay combined sewer system as compared to addressing the Lemay CSOs with other control technologies. Alternative A1: This alternative provides tunnel storage for all Mississippi River CSOs located north of the River Des Peres. Those lying south of the River Des Peres would be controlled with local storage tanks. Alternative A2: This alternative provides tunnel storage for all Mississippi River CSOs located within the Bissell Point service area. All CSOs to the Mississippi River within the Lemay service area would be controlled with local storage tanks. Alternative A3: This alternative provides tunnel storage for all Mississippi River CSOs located within the Bissell Point service area. All CSOs to the Mississippi River within the Lemay service area would be controlled by local treatment units. Alternative A4: This alternative provides tunnel storage for all Mississippi River CSOs. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-15 February 2011 Alternative A5: This alternative provides tunnel storage for all Mississippi River CSOs located within the Bissell Point service area. All CSOs to the Mississippi River within the Lemay service area would be eliminated by sewer separation. Alternative B – Local CSO Storage This alternative consists of the baseline plus the addition of above-grade or below-grade local storage tanks to store CSO flows at the various Mississippi River outfalls. The tanks can be sized to provide the desired level of control. It is anticipated that the existing Bissell Point Treatment Plant could handle the peak flows delivered under this alternative, although an analysis of storage volume vs. treatment capacity may be required. Alternative C – Local CSO Treatment This alternative consists of the baseline plus the addition of local treatment units to treat CSO flows at the various Mississippi River outfalls. The treatment units can be sized to provide the desired level of control. Alternative D – Sewer Separation This alternative involves separation of the entire combined sewer system directly tributary to the Mississippi River to eliminate the CSOs. 7.3.6 Upper River Des Peres – Integrated Control Alternatives Seven Integrated Control Alternatives were developed for the 39 CSOs that discharge to the Upper River Des Peres. Figure 7-5 shows the general location of these CSOs. Each alternative includes the common source control technologies and collection system controls previously described in Section 7.3.2. Each alternative also includes the continued operation of the Skinker-McCausland Tunnel. This tunnel was constructed to convey separate sanitary flows from those portions of the Upper River Des Peres subwatershed that are served by separate sewers. It express routes those flows around the combined portions of the River Des Peres collection system and therefore eliminates the overflow of this separate sanitary flow from the combined sewer system during wet weather. Figure 7-5 Upper River Des Peres CSOs Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-16 February 2011 Integrated Control Alternatives were defined that build upon the above controls to address the remaining CSO outfalls. The Integrated Control Alternatives are summarized on Table 7-5 and described below. Alternative Source Controls Collection System Controls Skinker- McCausland Tunnel Other CSO Controls A X X X sewer separation B X X X in-stream storage C1 X X X local storage C2 X X X partial separation and local storage D1 X X X local treatment D2 X X X partial separation and local treatment E X X X tunnel storage Table 7-5 Integrated Control Alternatives – Upper River Des Peres Alternative A – Sewer Separation This alternative involves separation of the remaining combined sewer system to eliminate the CSOs. Alternative B – Convert Upper River Des Peres to a Combined Sewer This alternative involves extending the combined sewer system upstream of Forest Park by enclosing the stream (essentially converting the streams to combined sewers, as was done decades ago in Forest Park). This would eliminate the CSO discharges in the Upper River Des Peres, but do nothing to reduce the impact of CSOs downstream (e.g., Middle and Lower River Des Peres). Alternative C – Local CSO Storage CSOs would be consolidated as appropriate to one or more local storage tanks. Ideally, the outfalls would be located away from public areas such as Heman Park and schools. Flows would be bled back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Alternative C1: In this alternative, CSO flows from the consolidated discharge points would be stored in tanks and slowly released back to the Lemay Treatment Plant as capacity became available. Alternative C2: This alternative is identical to Alternative C1 except that partial separation of the combined sewer system would reduce the size and costs for consolidation piping and flow storage. Alternative D – Local CSO Treatment In this alternative, CSOs would be consolidated as appropriate to one or more local treatment units. Ideally, the treatment units and outfalls would be located away from public areas such as Heman Park and schools. Alternative D1: In this alternative, CSO flows from the consolidated discharge points would be treated in one or more local treatment units and discharged into Upper River Des Peres. Alternative D2: This alternative is identical to Alternative D1 except that partial sewer separation would reduce the size and costs for consolidation piping and flow treatment. Alternative E – CSO Storage Tunnel In this alternative, CSOs would be consolidated as appropriate and conveyed to a storage tunnel. Ideally, the outfalls would be located away from public areas such as Heman Park and schools. Flows would be released back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Partial sewer separation could be accomplished where appropriate to reduce the size and costs for consolidation piping and tunnel storage. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-17 February 2011 7.3.7 River Des Peres Tributaries – Integrated Control Alternatives Ten Integrated Control Alternatives were developed for the 45 CSOs that discharge to the River Des Peres tributaries (Claytonia Creek, Hampton Creek, Black Creek and Deer Creek). Figure 7-6 shows the location of these CSOs. Figure 7-6 River Des Peres Tributaries CSOs Fourteen of these CSOs are currently scheduled for separation prior to the implementation of the future controls under the LTCP. These small sewer separation projects are intended to eliminate isolated CSOs in very small systems, or where the CSO results from only a few sanitary connections. Each of the Integrated Control Alternatives includes these combined sewer separations, as well as the common source control technologies and collection system controls previously described in Section 7.3.2. The Integrated Control Alternatives are summarized on Table 7-6 and described below. Alternative Source Controls Collection System Controls Small Combined Sewer Separations Other CSO Controls A X X X sewer separation B1 X X X consolidate CSOs to a single point and store flow B2 X X X consolidate CSOs to a single point and treat flow B3 X X X consolidate CSOs to a single point, partial separation to reduce flow, and treat flow C1 X X X consolidate CSOs to a few points and store flow C2 X X X consolidate CSOs to a few points and treat flow C3 X X X consolidate CSOs to a few points, partial separation to reduce flow, and treat flow D X X X tunnel storage E1 X X X local storage E2 X X X local treatment Table 7-6 Integrated Control Alternatives – River Des Peres Tributaries Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-18 February 2011 Alternative A – Sewer Separation This alternative involves separation of the remaining combined sewer system to eliminate the CSOs. Alternative B – Consolidate All CSOs to a Single CSO The following alternatives include the elimination of all CSO outfalls along the River Des Peres Tributaries by consolidating them into a single combined sewer discharging to the main channel of the River Des Peres. The consolidation sewer(s) will need to be sized to convey MSD’s design storm for combined sewer design. Alternative B1: In this alternative, CSO flows from the consolidated discharge point would be stored locally in a storage tank and bled back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Alternative B2: In this alternative, CSO flows from the consolidated discharge point would be treated locally in a treatment unit prior to discharge to the River Des Peres. Alternative B3: This alternative is identical to Alternative B2 except that the size and cost of conveyance piping and treatment unit would be reduced by partial separation of the combined sewer system. Alternative C – Consolidate CSOs to Remove from Neighborhoods This option is similar to Alternative B except that instead of consolidating the remaining CSOs to a single outfall on the River Des Peres, they would be consolidated to approximately 6 to 8 outfalls located along the tributaries. The consolidation sewer(s) will need to be sized to convey MSD’s design storm for storm sewer design. Alternative C1: In this alternative, CSO flows from the consolidated discharge points would be stored and bled back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Alternative C2: In this alternative, CSO flows from the consolidated discharge points would be treated locally in treatment units prior to discharge to the River Des Peres or tributaries. Alternative C3: This alternative is identical to Alternative C2 except that the size and cost of conveyance piping and treatment units would be reduced by partial separation of the combined sewer system. Alternatives D and E – No CSO Consolidation Under Alternatives D and E, there would be no consolidation of the remaining CSOs; all of them would remain at their current locations. Wet weather flows, up to the established level of control, would be conveyed to approximately 11 locations for storage or treatment as described below. Alternative D: In this alternative, CSO flows would enter drop shafts at the 11 locations into a deep storage tunnel. Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Partial sewer separation could be accomplished where appropriate to reduce the costs for CSO control. Alternative E1: In this alternative, CSO flows would be stored in above- or below-grade storage tanks at the 11 locations, and bled back to the Lemay Treatment Plant as capacity became available. It is anticipated that the existing plant could handle the peak flows delivered under this alternative. Alternative E2: In this alternative, CSO flows would be treated locally in treatment units at the 11 locations prior to discharge to the River Des Peres tributaries. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-19 February 2011 7.3.8 Lower and Middle River Des Peres – Integrated Control Alternatives Eight Integrated Control Alternatives were developed for the 50 CSOs that discharge to the Lower and Middle River Des Peres. Figure 7-7 shows the Middle and Lower River Des Peres CSOs. Figure 7-7 Lower and Middle River Des Peres CSOs Each alternative includes the common source control technologies and collection system controls previously described in Section 7.3.2. Each alternative also includes the following controls that have already been implemented or are currently being implemented in the combined sewer systems tributary to the Lower and Middle River Des Peres: • Sewer Separation for Lemay Outfalls 046, 049, 062, 168 and 177. These five outfalls are relatively small (15- to 48-inch diameter) in size. All are characterized as being primarily storm sewers with one or a few sanitary connections. MSD is currently designing sewer separation projects to separate these sewer systems, thereby eliminating the CSOs. • Lemay Overflow Regulation System. This project was constructed in the late 1990s and early 2000s. It essentially eliminated the influence of River Des Peres stage on the interception of flows from the various combined sewers tributary to the Lower and Middle River Des Peres. Prior to the implementation of this project, the interception of flow was reduced beginning at river stage 19. River stages of 19 feet and higher typically occur about 17 percent of the time. • Skinker-McCausland Tunnel. This project was constructed in the late 1990s and early 2000s. The Skinker-McCausland Tunnel serves as an express sewer to convey separate sanitary flows from the Upper River Des Peres area that previously had been discharged to downstream combined sewers and hence risked overflowing to the Middle River Des Peres during wet weather events. • Full Utilization of Excess Primary Treatment Capacity. Following the completion of ongoing projects, the Lemay Treatment Plant will have the ability to pump and treat additional wet-weather flow through its preliminary and primary treatment units, in excess of its secondary treatment Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-20 February 2011 capacity. The plant’s preliminary and primary treatment capacities will be 340 MGD; its secondary treatment capacity is 167 MGD. • Fix Inflow Sources to the main flow interception system. At present, system transients during wet weather cause manhole covers on the interceptor sewers beneath the Lower and Middle River Des Peres open channel to blow off, thereby allowing water from the River Des Peres to flow into the system, sometimes for extended periods of time. Other smaller inflow sources have also been identified. MSD has an ongoing project to remedy the causes of inflow. • Upstream SSO and CSO Volume Reduction. Any upstream projects (Upper River Des Peres and River Des Peres Tributaries) that result in a reduction of CSO and/or SSO volumes and pollutant loads will benefit the Middle and/or Lower River Des Peres. • River Des Peres Beautification/Improvements/Restoration. The U.S. Army Corps of Engineers has been studying various options for restoration or improvement to the River Des Peres. MSD has contributed to the funding for this study. Any resulting project(s) will be coordinated with the LTCP. Integrated Control Alternatives were defined that build upon the above-listed controls to address the remaining CSO discharges. The Integrated Control Alternatives are summarized on Table 7-7 and described as follows: Alternative Source Controls Collection System Controls Existing Controls1 Small Combined Sewer Separations Other CSO Controls A X X X X sewer separation B1 X X X X in-stream/channel flow storage B2 X X X X tunnel storage (under entire River Des Peres from mouth to western edge of Forest Park) B2A X X X X tunnel storage (under open channel portion of River Des Peres from mouth to Macklind Pump Station) B3 X X X X in-sewer flow storage beneath Forest Park, local treatment at Macklind Pump Station, smaller tunnel storage (under open channel portion of River Des Peres from mouth to Macklind Pump Station) B4 X X X X in-sewer flow storage beneath Forest Park, in-stream/channel flow storage, local treatment at Macklind Pump Station, smaller tunnel storage (under open channel portion of River Des Peres from mouth to Macklind Pump Station) B5 X X X X local storage B6 X X X X local treatment 1 Existing controls include the Lemay Overflow Regulation System, Skinker-McCausland Tunnel, and flow maximizationto the treatment plant. Table 7-7 Integrated Control Alternatives – Lower and Middle River Des Peres Alternative A – Sewer Separation This alternative involves separation of the combined sewer system to eliminate the CSOs. Alternative B – CSO Storage and Treatment The following alternatives all include the use of the existing flow interception system for conveyance of separate sanitary sewer flows and some combined sewer flows. Additional CSO flows would be either stored for later conveyance or treated prior to discharge to the River Des Peres. It is anticipated that the existing Lemay Treatment Plant could handle the peak flows delivered under these alternatives, although an analysis of storage volume vs. treatment capacity may be required. All of these options include the separation of any industrial sources, as well as any partial sewer separations, that are cost effective. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-21 February 2011 Alternative B1: In this alternative, CSO flows would be stored by converting the Lower and Middle River Des Peres open channels into partially or completely-covered storage channels. Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. Alternative B2: In this alternative, CSO flows would be conveyed to a storage tunnel under the entire Lower and Middle River Des Peres system (i.e., the Lower and Middle River Des Peres open channels and the enclosed section of the River Des Peres in Forest Park). Under this option, the enclosed portion of the river under Forest park would no longer serve as a combined sewer. Existing Outfall 063 would no longer be a CSO, but the existing connections to the enclosed section of the river under Forest Park would become new CSOs and require new diversion structures and interceptor sewers to convey dry weather flows. Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. Alternative B2A: In this alternative, CSO flows would be stored in a shorter storage tunnel, under only the Lower and Middle River Des Peres open channels, and be bled back to the Lemay Treatment Plant as capacity became available. The functionality of the combined sewer system beneath Forest Park would remain unchanged. Alternative B3: In this alternative, some CSO flow would be stored in the two enclosed 29-foot horseshoe sewers under Forest Park, but otherwise the functionality of the system under Forest Park would remain unchanged. A local treatment system would also be located adjacent to the Macklind Pump Station, using the pump station to convey flow to it. Reuse of this existing infrastructure decreases the overall volume of CSO flow to be stored in a tunnel. The remaining flow, to the desired level of control, would be stored in a smaller storage tunnel located under the Lower and Middle River Des Peres open channel. Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. Alternative B4: This alternative is similar to Alternative B3, except that additional flow storage would be accomplished in the Middle River Des Peres open channel by converting the channel into a partially or completely-covered storage channel. This further reduces the CSO volume to be stored in the tunnel under the Lower and Middle River Des Peres open channel. Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. Alternative B5: In this alternative, CSO flows would be stored in local (at the CSOs) above-grade or below-grade storage tanks, and bled back to the Lemay Treatment Plant as capacity became available. Alternative B6: In this alternative, CSO flows would be treated locally in treatment units prior to discharge to the River Des Peres. 7.4 Level 2 Screening Each of the 55 Integrated Control Alternatives described above was evaluated and screened to develop a short list of the most feasible and cost effective alternatives for further (Level 3) analysis. This screening was essential in order to focus the intense modeling and analysis efforts under the Level 3 analysis to only those alternatives with the best chances of actually being implemented. 7.4.1 Bases of Design of Integrated Control Alternatives For the Level 2 screening, the Integrated Control Alternatives were sized using the hydraulic model with discrete design storms, at a level of control of 12 overflows per year (a 1-month storm) for CSOs discharging directly to the Mississippi River, and 4 overflows per year (a 3-month storm) for all other CSOs, unless otherwise noted. For alternatives that served areas greater than 1.5 square miles (e.g., large tunnel storage systems), depth area reduction factors (DARF) specific to the St. Louis region were applied to the design storm rainfall input to the hydraulic model, in order to account for the spatial Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-22 February 2011 variability in rainfall over the larger areas. The various components of the alternatives were sized as follows: • Conveyance piping was sized based on a velocity of 4 feet/sec and the peak flow rates estimated by the hydraulic model. • Storage volume for tanks and tunnels was based on storing the overflow volumes estimated by the hydraulic model. • Pump stations were sized based on pumping out the volume of the tank or tunnel over a 24-hour period. • Treatment (sedimentation and disinfection) tank volume was estimated based on a contact time of 30 minutes and the peak flow rates estimated by the hydraulic model. 7.4.2 Bases for Cost Estimates After the conceptual sizing was performed, preliminary costs for each alternative were calculated. The cost opinions included in this document are considered to be Class 4: Concept Study or Feasibility Level Estimates, with an expected accuracy of -15% to +30% (Cost Estimate Classification System, Association for the Advancement of Cost Engineering Recommended Practice No. 17R-97, 1997). The cost opinions are of this accuracy because the alternatives have been prepared with a minimum of detailed design data and for the purpose of relative comparison. This level of accuracy is appropriate for screening-level comparisons between CSO control alternatives. The Level 2 screening cost estimates for each Integrated Control Alternative include construction and capital costs. Costs for CSO controls that have already been implemented are not included in the estimates. A present worth or life-cycle analysis, including consideration of annual operation and maintenance costs, was not performed for the Level 2 estimates, but is included with the Level 3 alternatives evaluation in Section 8 of this report. The following cost bases were used in preparation of construction cost estimates: • Construction Cost Index – An Engineering News Record (ENR) Construction Cost Index of 7950 was used for the Level 2 alternatives evaluation. • Approach to Estimating Construction Costs – Costs have been prepared using the following resources: – Cost curves from: ƒ Construction Costs for Municipal Wastewater Conveyance Systems: 1973-1979, EPA 430-9-81-003 (EPA, 1981) ƒ Manual - Combined Sewer Overflow Control, EPA 625-R-93-007 (EPA, 1993a) ƒ Cost Estimating Manual – Combined Sewer Overflow Storage and Treatment, EPA 600-2-76-286 (EPA, 1976) ƒ Pumping Station Design (Sanks, 1998). – Unit costs in dollars per gallon or cost per linear foot obtained from projects (planning studies and bid tabulations) in several cities, including St. Louis, Indianapolis, Washington D.C., and Richmond Virginia. Costs have been adjusted for relative characteristics such as complexity and location using best engineering judgment. – Where facilities are unique or customized, and cost curve data does not exist, conceptual layouts of facilities were prepared and costs were estimated by performing takeoffs to estimate quantities. Unit costs were then applied to the estimated quantities. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-23 February 2011 • Calculation Procedure - the calculation procedure in Table 7-8 was used for estimating construction and capital costs. Line Number Description Calculation Procedure 1 Subtotal of Construction Line Items -- 2 Construction Contingencies 25% x Line 1 3 Total Construction Cost Sum of Lines 1 and 2 4 Engineering, legal, and Admin. Fees 20% x Line 3 5 Total Capital Cost Sum of Lines 3 and 4 Table 7-8 Calculation Procedure for Construction Cost Opinions 7.4.3 Alternatives Screening Process The Integrated Control Alternatives were screened using the criteria defined in Table 7-9. Additional site-specific criteria, if any, that were used in the screening process are noted in the screening results portion of this section. The screening process included input from MSD’s engineering and operations staff, the CSO Stakeholder Advisory Committee and the public. Additionally, potential CSO control facility sites were identified, evaluated, and investigated (physically and with Geographical Information Systems) to assist in determining the feasibility of each alternative. Criteria Description Affordability The capital cost and long-term affordability of all alternatives affects the ability of St. Louis MSD to minimize the cost of service to its customers and the degree to which resources may be diverted from other MSD programs. CSO/Load Reduction All alternatives will reduce the overflow volume, frequency, and duration therefore reducing pollutant concentrations in the river. Pollutants include solids, disinfection byproducts, ammonia, phosphorous, metals, BOD, and viruses. Constructability Most alternatives can be constructed, for a cost. The constructability of an alternative decreases if a tank or conveyance piping cannot fit on an approved site. Mitigating the decreased constructability of the alternatives could involve negotiating for a smaller tank/pipe, acquiring additional land for a tank, or building additional tanks/pipes. Expandability Adaptability to possible future regulatory requirements (requiring a greater level of control) should be considered. For example, a pipe or tunnel size cannot be easily increased in a size once it is built, whereas a tank can be expanded if the required space is available. Operability All alternatives will require varying levels and frequencies of operator attention during normal operation. Generally, remote facilities will require a greater level of operator attention and present more difficulties in operation. Treatment tanks with chemical disinfection will require more attention than storage tanks. Public Acceptability Public acceptance should be considered in the evaluation of all alternatives. Reuse of Existing Facilities Existing infrastructure should be reused to the greatest extent possible. Infrastructure Rehabilitation and Upgrade All alternatives should consider the condition and capacity of the existing collection system and WWTP infrastructure, and account for any rehabilitation or upgrade that may be necessary as a result of the CSO LTCP projects. Table 7-9 Alternative Screening Criteria 7.4.4 Level 2 Screening Results The Level 2 screening results are presented below for each receiving water segment. Capital cost data for each Integrated Control Alternative are presented in tabular format to allow for easy comparison. A discussion of cost factors and significant non-monetary screening factors is also presented, providing a clear description of the decision making process used to screen the alternatives to those that are most feasible and cost-effective. The Integrated Control Alternative(s) selected for further evaluation under the Level 3 analysis are highlighted on each of the comparison tables. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-24 February 2011 7.4.4.1 Maline Creek The Maline Creek Level 2 alternative analysis capital costs are shown in Table 7-10. The alternatives screening process resulted in the following conclusions: • Alternative A, an express sewer, was dismissed from further consideration because it could not provide the desired level of control (4 overflows per year) and was considerably more expensive than the other alternatives. • All of the “B” alternatives, which use the existing tunnel as a sanitary express sewer, were dismissed because they cost more than their counterpart “C” alternatives (e.g., compare Alternative C1 to Alternative B2, etc.). • Alternative D, outfall relocation, was eliminated from further analysis as it did not provide a net environmental benefit compared to other alternatives with comparable costs. Relocating the outfall to the Mississippi River simply transfers the problem. • Alternatives C4 and C5 were eliminated due to the high cost required for partial sewer separation. Alternatives C1 and C2 provide equivalent control to Alternatives C4 and C5, respectively, but at a lower capital cost. • Alternative C3 was dismissed due to the high cost and unfeasibility of complete sewer separation. Note that the cost of sewer separation given for this alternative represents only the cost of separating the public sewer system. Sewer separation will also require private property owners to separate their plumbing systems, both internal and external to their structures. MSD does not have legal authority to mandate separation of combined plumbing on private property. • Alternative C6 provides identical benefits as Alternative C2 (both use local treatment), except in- sewer storage is utilized along with a smaller treatment tank in Alternative C6. In-sewer storage, however, entails some risk of stored flow backing up into residential basements in the event of a problem. For this reason, and the fact that there appear to be no cost savings from in-sewer storage, Alternative C6 was eliminated from further consideration. Alternative Description Total Capital Cost ($million) A Build new express sewer to convey sanitary flows from Maline Creek and Watkins Creek to Bissell Point Treatment Plant. Use existing tunnel to convey combined flows to Bissell Point Treatment Plant. $148 Use existing tunnel as express sewer to convey sanitary flows from Maline Creek and Watkins Creek to Bissell Point Treatment Plant. Combined flows controlled by: B1 CSO storage tunnel $199 B2 Local storage tanks $241 B3 Local CSO treatment units $84 B4 Sewer Separation $336 B5 Local storage tanks for reduced volume after partial sewer separation $302 B6 Local treatment units for reduced flows after partial sewer separation $154 B B7 Local treatment units for reduced flows after in-sewer storage $251 Use existing tunnel to convey both sanitary and combined flows. Add local storage tank at Maline Dropshaft to store excess flows from Bissell Point Outfall 052. Excess combined system flows from Bissell Point Outfall 051 controlled by: C1 Local storage tanks $69 C2 Local CSO treatment units $56 C3 Sewer Separation $164 C4 Local storage tanks for reduced volume after partial sewer separation $130 C5 Local treatment units for reduced flows after partial sewer separation $124 C C6 Local treatment units for reduced flows after in-sewer storage $56 D Local treatment unit at Bissell Point Outfall 051, relocation of Bissell Point Outfall 051 from Maline Creek to the Mississippi River, and local storage tank at Bissell Point Outfall 052 $61 Table 7-10 Maline Creek Level 2 Analysis Cost Summary Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-25 February 2011 Thus, the two remaining alternatives were C1 and C2. Comparing these alternatives yielded the following results: • Both alternatives employ a storage tank to control overflows from Outfall 052. Alternative C1 uses a local storage tank to control Outfall 051, with the stored flow receiving full secondary treatment at the Bissell Point Treatment Plant prior to discharge to the Mississippi River. Alternative C2 uses a treatment unit to provide the equivalent of primary treatment and disinfection prior to discharge to Maline Creek. Alternative C1 provides greater environmental benefit than Alternative C2 due to its greater degree of treatment and discharge to a larger receiving stream. • The storage tank in Alternative C1 could be placed underground, as opposed to the above-ground treatment tanks in Alternative C2. Therefore, public acceptance of the storage solution may be greater. • There is concern with Alternative C1, however, regarding sufficient space being available depending on the final size of the tank (level of control). • Alternative C2 is less expensive than Alternative C1. For all of the above reasons, it was determined that both Alternative C1 and Alternative C2 should progress to the Level 3 analysis. It should also be noted that if a new CSO storage tunnel is chosen as the preferred alternative for the Mississippi River outfalls, it may prove cost-effective to extend this storage tunnel to Maline Creek for CSO control than to control overflows through local storage or treatment. 7.4.4.2 Gingras Creek The Gingras Creek Level 2 alternative analysis capital costs are shown in Table 7-11. The alternatives screening process resulted in the following conclusions: • Alternative A, sewer separation, was eliminated from further consideration because it would place greater strain on the downstream sanitary sewer system which may create a more severe SSO problem. Additionally, complete separation is very costly, especially when the cost for separating plumbing on private property is added to the cost noted in the table for public system separation. • Alternatives E, F, and G were eliminated from further consideration as they are not cost-effective compared to their no-separation counterparts of Alternatives C, D, and B, respectively. Alternative Description Total Capital Cost ($million) A Complete sewer separation of the combined system into separate storm and sanitary sewer systems, thereby eliminating the CSO $12.0 B Outfall relocation $8.3 C Local storage $10.9 D Local treatment $5.9 E Partial separation and below-grade storage $13.0 F Partial separation and local treatment $10.8 G Partial separation and outfall relocation $10.7 Table 7-11 Gingras Creek Level 2 Analysis Cost Summary Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-26 February 2011 Therefore, the remaining alternatives – B, C, and D – were viewed as the most feasible and cost- effective. Comparing these alternatives yielded the following results: • Alternative D, local treatment, has the lowest capital cost, but results in treated and untreated overflows to Gingras Creek. • Alternative C, local storage, has the highest capital cost. While it captures a significant amount of flow for full secondary treatment, it still results in some untreated overflows to Gingras Creek. • Alternative B, outfall relocation, consists of extending the combined sewer from its current outfall location to the Baden trunk sewer. This alternative is intermediate in costs, but completely eliminates CSOs to Gingras Creek. For the reasons noted above, it was determined that all three alternatives should progress to the Level 3 analysis. Recent Sanitary Sewer Evaluation Survey (SSES) investigations in the area directly to the west of this combined sewer area have identified the presence of three separate storm sewers that discharge to the combined sewer system. The Level 3 analysis considered separation of these storm sewers from the combined sewer system to further reduce the CSO control costs of the three remaining alternatives. 7.4.4.3 Mississippi River The Mississippi River Level 2 alternative analysis capital costs are shown in Table 7-12. The alternatives screening process resulted in the following conclusions: • Alternative D was eliminated from further consideration due to the extremely high cost of sewer separation. As noted above, this cost estimate is an under-estimate of the true cost because of difficulty in assessing feasibility and cost of re-plumbing combined plumbing systems within private property. • Alternatives B, local storage, and C, local treatment, were dismissed due to their high cost compared to other alternatives. Alternative C, local treatment, provides less environmental benefit (primary treatment only), additional operating and maintenance issues with a large number of distributed treatment systems, public acceptance issues, and greater probability for disinfection by-products associated with the disinfection of partially-treated CSOs. Additionally, it was determined that most of the CSO locations do not have available space for construction of the storage or treatment tanks. • Of the remaining options, all based on a storage tunnel concept, Alternative A5 was eliminated from further consideration due to its high cost and concerns over the feasibility of separating three large outfalls, ranging from 48 to 96-inches diameter (Lemay Outfalls 142, 143 and 144). • Alternative A3 was dismissed as it provides less environmental benefit than Alternative A2, for essentially the same cost. Alternative A3 entails local treatment at the Lemay outfalls to the Mississippi River whereas Alternative A1 provides local storage with stored flows receiving secondary treatment at the Lemay Treatment Plant. • The remaining alternatives – A1, A2, and A4 – all provide the same benefit, but Alternative A2 does so at the lowest capital cost. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-27 February 2011 For the above reasons, it was determined that Alternative A2 should progress to the Level 3 analysis. Alternative Description Total Capital Cost ($million) A1 Storage tunnel along the Mississippi River (for all Lemay outfalls except Jefferson Barracks) with local storage for Jefferson Barracks Outfalls $788 A2 Storage tunnel along the Mississippi River with local storage for all Lemay Outfalls $701 A3 Storage tunnel along the Mississippi River with local treatment for all Lemay Outfalls $702 A4 Storage tunnel along the Mississippi River with storage tunnel for all Lemay Outfalls $775 A Lemay Options A5 Storage tunnel along the Mississippi River with sewer separation for all Lemay Outfalls $838 B Local storage $1,200 C Local treatment $883 D Sewer separation $4,740 Table 7-12 Mississippi River Level 2 Analysis Cost Summary 7.4.4.4 Upper River Des Peres The Upper River Des Peres Level 2 alternative analysis capital costs are shown in Table 7-13. The alternatives screening process resulted in the following conclusions: • Alternatives C2 and D2 were eliminated from further consideration due to the additional cost of partial sewer separation making them more costly than their non-separation counterparts, Alternatives C1 and D1, respectively. • Alternative A, sewer separation, was eliminated due to its high cost and feasibility concerns, as noted previously under the screening results for other receiving water segments. Additionally, separation of the combined sewer system would put additional strain on the existing sanitary sewer system. • Alternative B was eliminated from further consideration because it simply converts streams to sewers. Estimated costs for this option were high, but they were also difficult to estimate due to the close proximity of the creeks to homes. • Alternative C1, local storage, provides more environmental benefit than Alternative D1, local treatment. The stored overflow volume under Alternative C1 would receive full secondary treatment at the Lemay Treatment Plant, whereas Alternative D1 provides only primary treatment and disinfection, and discharges the partially-treated flow to the Upper River Des Peres. Alternative D1 also presents a higher risk of discharging disinfection by-products to the environment. Therefore, Alternative D1 was eliminated from further consideration. • Both remaining alternatives – C1 and E – provide storage of combined sewer flows for full treatment at the Lemay Treatment Plant once capacity becomes available. Alternative C1, local storage, has higher capital costs that Alternative E, tunnel storage, and there are feasibility concerns regarding the ability to find open space for local storage locations. Storage tanks would be in approximately 10 central locations and would likely be buried. Property buyout costs were not included in the cost estimates. Alternative E will require further refinement during preliminary design to determine whether it is best to include satellite storage locations for a few of the remotely-located CSOs that would be impractical or too costly to convey to the tunnel. The storage tunnel could possibly be Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-28 February 2011 extended in length, so that a segregated portion of it could be dedicated to storage of peak wet weather sanitary flows, to help control SSOs in the area. For the above reasons, Alternative E, tunnel storage, was the preferred alternative to progress to the Level 3 analysis. Alternative Description Total Capital Cost ($million) A Complete sewer separation $324 B Creek covers $320 C1 Local storage $270 C C2 Local storage with partial separation $338 D1 Local treatment $253 D D2 Local treatment with partial separation $333 E Storage tunnel $227 Table 7-13 Upper River Des Peres Level 2 Analysis Cost Summary 7.4.4.5 River Des Peres Tributaries The Level 2 alternative analysis capital costs for the River Des Peres Tributaries are shown in Table 7-14. The alternatives screening process resulted in the following conclusions: • Alternative A, sewer separation, was eliminated due to its high cost and feasibility concerns, as noted previously under the screening results for other receiving water segments. Additionally, separation of the combined sewer system would only put additional strain on the existing sanitary sewer system. • The “C” alternatives, which involve partial consolidation of the CSO locations in addition to storage or treatment of flow, are each significantly more expensive than the “D” and “E” alternatives, which have no outfall consolidation. The water quality benefits of consolidating the same CSO volume into a fewer number of outfalls located along the tributaries was deemed to be insignificant. This minor benefit, and the increase in capital cost of between $118 and $281 million, were the primary reasons for eliminating the “C” alternatives from further consideration. Concerns also existed over the feasibility of locating storage or treatment units in the neighborhoods along the tributaries. • The “B” alternatives are attractive from the standpoint that they eliminate CSOs along the tributaries and do not require the placing of storage or treatment units in the neighborhoods along the tributaries. Alternative B1 would provide the highest benefit, as the stored flows would receive full secondary treatment at the Lemay Treatment Plant. The high cost of all of the “B” alternatives, and significant concerns over the feasibility of installing large diameter conveyance piping that would allow elimination of the CSO outfalls, were the primary reasons for eliminating the “B” alternatives from further consideration. • Alternative E2, local treatment, has the lowest capital cost, but also provides the least benefit in terms of pollutant loading reduction to the tributaries. Additionally, public acceptance of this alternative would be low, as chemical shipment to, and maintenance of, the treatment units would be required in highly residential areas. Alternative E2 also presents a higher risk of discharging disinfection by-products to the environment. Alternative E2 was dismissed for these reasons. • Alternatives D, tunnel storage, and E1, local storage, both provide for storage of CSO flows for full secondary treatment at the Lemay Treatment Plant. Both offer the same benefit for essentially the same cost. Due to concerns over the feasibility of placing local storage tanks at 11 locations along the tributaries, it was determined that Alternative D was the most feasible option and should progress to the Level 3 analysis. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-29 February 2011 Because of the attractiveness of consolidating the outfalls along the tributaries to a single location along the main channel of the River Des Peres (as in Alternative B), it was decided to expand the analysis of Alternative D under the Level 3 screening process (i.e., an additional Alternative). This expanded analysis would consider whether an oversized storage tunnel could accomplish the flow conveyance necessary to allow consolidation of the outfalls. Alternative/Description Total Capital Cost ($million) A Complete Sewer Separation $478 Consolidate all CSOs along River Des Peres tributaries to a single outfall near the main channel of the River Des Peres (consolidation piping sized for 20-year storm sewer service) B1 CSO control via local storage at the single CSO $598 B2 CSO control via local treatment at the single CSO $553 B B3 CSO control via local treatment at the single CSO, with the size of conveyance and treatment reduced by partial (soft) sewer separation $557 Consolidate all CSOs along River Des Peres tributaries to approx. 7-8 outfalls located away from backyards (consolidation piping sized for 20-year storm sewer service) C1 CSO control via local storage at the 7-8 CSO locations $318 C2 CSO control via local treatment at the 7-8 CSO locations $481 C C3 CSO control via local treatment at the 7-8 CSO locations, with the size of conveyance and treatment reduced by partial (soft) sewer separation $475 CSOs remain and discharge 4x per year; 3-month storm flows conveyed to consolidated locations for storage or treatment D Deep tunnel storage $203 E1 Local storage $200 E E2 Local treatment $163 Table 7-14 River Des Peres Tributaries Level 2 Analysis Cost Summary 7.4.4.6 Lower and Middle River Des Peres The Lower and Middle River Des Peres Level 2 alternative analysis capital costs are shown in Table 7-15. The alternatives screening process resulted in the following conclusions: • Alternative A, sewer separation, was eliminated due to its high cost and feasibility concerns, as noted previously under the screening results for other receiving water segments. • Two flow storage alternatives, Alternatives B1 and B5, were also dismissed due to high costs as compared to tunnel storage (Alternatives B2, B2A, and B3). • Alternative B6 was determined to be undesirable because all of the overflow would be treated locally and discharged back to the River Des Peres, whereas with the other alternatives, the stored flow would receive full secondary treatment at the Lemay Treatment Plant. Additionally, Alternative B6 was eliminated from further consideration due to feasibility concerns over space availability and public acceptance. The remaining alternatives all include storage of flow in a tunnel under the River Des Peres. Each alternative includes features that impact the sizing and cost of the storage tunnel: • Alternative B2 includes storage in a new tunnel under the entire open channel of the Lower and Middle River Des Peres and under the enclosed portion of the river through Forest Park. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 7. CSO CONTROL OPTIONS AND SCREENING Page 7-30 February 2011 Disadvantages of this alternative include the high capital cost, an increase in the number of CSOs and diversion structures that require maintenance, and the significant amount of construction required in Forest Park for new outfall and diversion structures and dry-weather flow interceptor sewers. Advantages include the reduction in dry weather flows to the Lemay Treatment Plant as the stream flow that currently enters the combined sewer system would no longer be intercepted under this option. • Alternative B2A includes a shorter but larger-volume storage tunnel. The tunnel would extend under the open channel portion of the Middle and Lower River Des Peres from the Macklind Pump Station to the Mississippi River. The functionality of the existing combined sewer system beneath Forest Park would remain unchanged. This alternative would be easiest to construct but carries a higher capital cost. • Alternative B3 includes a similar tunnel as in Alternative B2A, but it is smaller in volume because this alternative maximizes use of the existing infrastructure to accomplish flow storage and treatment. Storage in the existing 29-ft horseshoe sewers under Forest Park can reduce the overflow volume in a 3-month event by 25 percent. The existing Macklind Pump Station can also be used to pump into a new 100-MGD treatment facility for another 25 percent reduction in overflow volume. Alternative B3 offers the lowest capital cost, but some risk may be involved when storing flow in the Forest Park horseshoe sewers. • Alternative B4 includes storage in the 29-ft horseshoe sewers under Forest Park, covering a portion of the Middle River Des Peres to allow for additional flow storage, and storage of the remaining combined flows in a tunnel under the Lower River Des Peres. This alternative was dismissed due to its high cost. For the reasons noted above, Alternatives B2, B2A, and B3 were selected to move forward into the Level 3 analysis. Alternative/Description Total Capital Cost ($million) A Complete sewer separation $2,520 B1 Storage in covered River Des Peres channel $1,820 B2 Storage in tunnel under Lower and Middle River Des Peres to Lemay Outfall 063 $734 B5 Local storage $1,210 Base Alternatives B6 Local treatment $779 B2 Storage in tunnel under all River Des Peres including Forest Park $828 B2A Storage in tunnel under Lower and Middle River Des Peres to Lemay Outfall 063 $734 B3 Storage in tubes under Forest Park coupled with local treatment system + storage tunnel under Lower and Middle River Des Peres $671 Tunnel Alternatives B4 Storage in tubes under Forest Park + storage in Middle River Des Peres + storage tunnel under Lower River Des Peres $1,180 Table 7-15 Lower and Middle River Des Peres Level 2 Analysis Cost Summary Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-1 February 2011 8. ALTERNATIVES EVALUATION 8.1 Introduction This section describes the process that MSD used to analyze and evaluate the 12 cost-effective Integrated Control Alternatives that remained after the Level 2 Screening process described in Section 7. As noted in Section 7.3.2, these Integrated Control Alternatives are combinations of source controls and collection system controls determined to be applicable to all alternatives, long-term CSO controls that have already been implemented by MSD or are currently being implemented, and new long-term controls necessary to meet CSO control goals. The long-term controls already implemented or currently being implemented by MSD were described in Section 3.2.6, and represent an investment of $0.6 billion that has already reduced annual CSO volumes by 38 percent. These controls include maximizing the flows to the Bissell Point and Lemay Treatment Plants. The process of analysis and evaluation of the remaining 12 Integrated Control Alternatives, to determine the preferred alternative, is referred to in this report as the “Level 3 screening process.” The Level 3 screening process resulted in the identification of five CSO control scenarios that consist of combinations of the 12 Integrated Control Alternatives. These scenarios were presented to MSD’s Stakeholder Advisory Committee and the general public. A preferred alternative was then selected to form the basis of the CSO control measures recommended in this LTCP. MSD reviewed the existing water quality (described in Section 3) and the results of the bounding analyses (discussed in Section 6), and determined that compliance with water quality standards would not be a distinguishing factor in selecting a preferred control scenario. For the Mississippi River, monitoring data show that water quality standards are being met under existing conditions. For the tributaries, the bounding analyses showed that many locations along the waterways were meeting water quality standards under existing conditions. Where standards were not being met under existing conditions, the bounding analysis showed that even complete CSO removal resulted in relatively small improvements in compliance with water quality standards. One improvement that is to be expected with CSO control is orders-of-magnitude reductions in peak bacteria densities during wet weather (rainfall) events. This reduction can be correlated with reductions in CSO volume and frequency. Based on these results, MSD determined that detailed comparisons of alternatives using compliance with water quality standards would not advance the CSO control decision making process. This section describes the Level 3 screening process and presents the results for each of the receiving waters. This section also presents the factors that were considered in using the results of the Level 3 screening process to develop five CSO control scenarios and to select the preferred alternative. 8.2 Level 3 Screening The following tasks were performed during the Level 3 screening process: • MSD evaluated a range of sizes of the 12 Integrated Control Alternatives that would achieve 0, an average of 1 to 3, an average of 4 to 7, and an average of 8 to 12 overflow events per year in accordance with the CSO Control Policy. • MSD analyzed the impact that each of the 12 Integrated Control Alternatives is estimated to have on peak instantaneous and sustained flows to the Lemay Treatment Plant and the Bissell Point Treatment Plant. • MSD estimated project costs for each of the 12 Integrated Control Alternatives, including capital costs, annual operation and maintenance costs, and total present worth (life-cycle) costs. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-2 February 2011 • MSD estimated the benefits arising from the implementation of each of the 12 Integrated Control Alternatives in terms of the reduction in number of CSO events for the typical year. Estimates were also made of the reduction in volume of CSOs and the reduction in pollutant loading from CSOs, for the typical year. • MSD conducted cost-performance (“knee of the curve”) analyses comparing estimated costs to the estimated benefits. Curves presenting costs versus estimated numbers of CSO events are presented in this LTCP report. • MSD involved its Stakeholder Advisory Committee and the public in reviewing the results of the Level 3 screening process. These tasks are described further in subsequent paragraphs of this section. 8.2.1 Bases of Design of Integrated Control Alternatives For the Level 3 screening, the 12 Integrated Control Alternatives were conceptually sized for different levels of control, i.e., number of overflow events. Hydraulic model results for a continuous simulation, using the typical year (Year 2000) rainfall, were used to size the controls for each alternative. The various components of the alternatives were sized as follows: • Conveyance piping was sized based on a velocity of 4 feet per second and the peak flow rates estimated by the hydraulic model. • Storage volume for tanks and tunnels was determined iteratively using the model results such that overflows from individual events, or from combinations of “back-to-back” events, provided the desired level of control. • Pump stations were generally sized to pump out storage devices within 48 hours. The ability of the Bissell Point and Lemay Treatment Plants to provide treatment to the increased flow was also considered. The feasibility and cost of plant expansion (where the need for more capacity was suggested) was balanced against the cost of over-sizing the storage tank or tunnel to accommodate reduced pump-out rates. • Treatment (sedimentation and disinfection) tank volume was estimated based on providing a minimum contact time of 30 minutes for all events up to the desired level of control. 8.2.2 Bases for Cost Estimates After the conceptual sizing was performed, preliminary costs for each alternative were estimated. Construction and capital costs were developed using the same methodology as used for the Level 2 screening estimates. An Engineering News Record Construction Cost Index of 8100 was used for the Level 3 screening. Costs for CSO controls that have already been implemented are not included in the estimates. Operating and maintenance (O&M) costs were estimated for each alternative for labor, maintenance parts/equipment, utilities, and chemicals such as disinfectants. Total present worth (life cycle) costs, combining the capital and O&M costs, were calculated for each alternative based on a 20-year period, 3 percent inflation rate, and 7 percent interest rate1. Table 8-1 indicates how the engineering opinion of total present worth costs was calculated. 1 Sensitivity analyses conducted subsequent to the Level 3 screening indicated that the screening results, and the decisions based on those results, were not sensitive to varying, within reasonable ranges, the assumed values in the present worth calculations. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-3 February 2011 Line Number Description Calculation Procedure 1 Subtotal of Construction Line Items -- 2 Construction Contingencies 25% x Line 1 3 Total Construction Cost Sum of Lines 1 and 2 4 Engineering, Legal, and Admin. Fees 20% x Line 3 5 Total Capital Cost Sum of Lines 3 and 4 6 Annual O&M Costs -- 7 Present Worth of Annual O&M Costs PW Factor x Line 6 8 Total Present Worth Sum of Lines 5 and 7 Table 8-1 Calculation Procedure for Level 3 Cost Opinions 8.2.3 Determination of CSO Control Benefits CSO control benefits were assessed based on reduction in the number of overflows per year, and the volume and pollutant loads discharged from the CSOs for each of the 12 alternatives. The hydraulic model, using the typical year rainfall, was used to estimate the remaining CSO volumes for each level of control. Pollutant loadings (BOD5, TSS and E. coli) from CSOs were calculated using these volumes and the event mean concentrations appropriate for that portion of the combined sewer system. For alternatives employing CSO treatment, the pollutant loading calculations included estimated treatment efficiency. Specific assumptions are noted for each alternative, as applicable. 8.2.4 Screening Procedures The results of the costs and benefits analyses discussed above were used as a starting point for screening the 12 alternatives to identify preferred integrated alternatives for each receiving water. In addition, several qualitative criteria were used during the Level 3 screening process. MSD, its Stakeholder Advisory Committee and the public, determined that the following qualitative criteria were the most important for selecting CSO controls: • Cost/Affordability • Environmental Benefit • Feasibility/Constructability/Technical Limitations • Adaptability of Controls to Future Regulations/Climate Change, Flexibility and Expandability of Solutions The qualitative criteria listed below were determined to have a lesser influence than the above criteria, but were still considered to be important: • Operability and Maintainability of CSO Controls • Public Acceptance/Opinion/Community Involvement in Solutions • Influence of Political Factors/Pressure (St. Louis’ multi-jurisdictional nature) • Ability to Integrate Green Controls into Design • Compatibility of CSO Solutions with other MSD programs (e.g., SSO Controls) Finally, an overarching program goal was to prioritize CSO control efforts by proximity to residential neighborhoods and public health and human safety concerns. 8.3 Level 3 Screening Results The criteria described above were used to evaluate each of the 12 alternatives during the Level 3 screening process. The results are presented below for each receiving water segment. Cost-performance Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-4 February 2011 curves present the “knee of the curve” analysis for each alternative in terms of capital and total present worth costs versus average number of overflow events per year. As noted previously, reductions in CSO volume and pollutant loadings do not result in significant improvements in compliance with water quality standards. Therefore, the cost-performance analysis of each alternative was based on the occurrence of overflows (i.e., average number of events in the typical year) rather than on CSO volume or pollutant loadings. Itemized cost summaries of the capital and O&M costs for each alternative at differing levels of control are presented in Appendix I. Appendix J contains the estimated reductions in overflow volume and pollutant loadings at each level of control investigated2. The Level 3 screening results presented below also include the impacts of each alternative on peak and sustained flows to the treatment plants, and other screening factors that were considered in the choice of the preferred alternative. 8.3.1 Maline Creek 8.3.1.1 Alternatives The Level 2 screening process identified two Integrated Control Alternatives for the CSOs discharging to Maline Creek. These alternatives are shown on Figure 8-1. Figure 8-1 Maline Creek CSOs - Integrated Control Alternatives 2 Note that the estimated reductions in overflow volume and pollutant loadings shown in Appendix J do not include any synergistic effects that occur when the individual CSO control measures are combined together in the complete Long-Term Control Plan. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-5 February 2011 Alternative 1 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Continued operation and maintenance of the Bissell Point Overflow Regulation System to control the influence of Mississippi River stage on the interception of flows from the Riverview combined sewer system. • Infiltration and Inflow (I/I) control in the sanitary sewer systems tributary to the Maline Drop Shaft. • Sewer separation of Bissell Point Outfall 053. • Sewer separation of Bissell Point Outfall 060. • A local storage tank to collect and store the infrequent overflows from Bissell Point Outfall 052 (Maline Drop Shaft). • A local storage tank to collect and store CSO flows at Bissell Point Outfall 051. Stored flows would be later bled back to the Bissell Point Interceptor Tunnel for secondary treatment at the Bissell Point Treatment Plant. Alternative 2 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Continued operation and maintenance of the Bissell Point Overflow Regulation System to control the influence of Mississippi River stage on the interception of flows from the Riverview combined sewer system. • I/I Control in the sanitary sewer systems tributary to the Maline Drop Shaft. • Sewer separation of Bissell Point Outfall 053. • Sewer separation of Bissell Point Outfall 060. • A local storage tank to collect and store the infrequent overflows from Bissell Point Outfall 052 (Maline Drop Shaft). • A local treatment plant to treat CSO flows at Bissell Point Outfall 051 prior to discharge to Maline Creek. 8.3.1.2 Cost-Performance Analysis Cost-performance curves are presented in Figures 8-2 and 8-3 for Alternatives 1 and 2 respectively. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. The cost scales differ between the figures. Figure 8-4 compares the total present worth of the two alternatives. Note that the curves represent the costs and benefits only for additional controls to be installed after the planning process is completed and approved. The costs and benefits of controls that MSD has implemented during the planning process or is currently implementing are not included. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-6 February 2011 $0 $50 $100 $150 $200 $250 $300 $350 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-2 Maline Creek Cost-Performance - Alternative 1 $0 $20 $40 $60 $80 $100 $120 $140 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-3 Maline Creek Cost-Performance - Alternative 2 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-7 February 2011 $0 $50 $100 $150 $200 $250 $300 $350 024681012141618 Average Number of Overflows per YearTotal Present Worth ($Million)Alternative 1 Alternative 2 Figure 8-4 Maline Creek Total Present Worth Comparison 8.3.1.3 Impact on Bissell Point Treatment Plant Alternative 1 includes the use of tanks to store flows from two CSOs to Maline Creek until after the CSO event ceases, at which time the stored flows would be pumped back to the Bissell Point Interceptor Tunnel to receive full secondary treatment at the Bissell Point Treatment Plant. Peak instantaneous flows to the treatment plant do not change under this alternative. Sustained flows to the treatment plant increase modestly (up to 20 MGD, depending on the level of control) during the period when the storage tanks are being drained. Alternative 2 includes the use of a single tank to store flows from Outfall 052; overflows from Outfall 051 would be locally treated and discharged to Maline Creek. This alternative also has no impact on the peak instantaneous flows to the Bissell Point Treatment Plant. Sustained flows would increase less than Alternative 1 (up to 5 MGD, depending on the level of control) during the period when the storage tank is being drained. In both cases, the increase in sustained flow to the treatment plant is well within the ability of the plant to provide secondary treatment and meet its operating permit requirements. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-8 February 2011 8.3.1.4 Alternatives Evaluation Table 8-2 presents the evaluation of the two alternatives for the primary and secondary Level 3 evaluation criteria for the Maline Creek CSOs. Criteria Evaluation Cost (capital and total present worth) Alternative 2, local treatment at Outfall 051, is less expensive than Alternative 1, local storage at Outfall 051, for all levels of control. Investments above 6 overflows per year yield diminishing returns. Alternative 1 becomes considerably more expensive than Alternative 2 at higher levels of control. Environmental benefit Alternative 1 provides a higher benefit to Maline Creek as stored flows receive secondary treatment and are discharged to the Mississippi River, whereas Alternative 2 provides only primary treatment and disinfection, with discharge to Maline Creek. Technical feasibility The feasibility of Alternative 1 decreases at higher levels of control (less than 6 overflows per year) due to the required storage tank size and limited space near Outfall 051. Primary Adaptability, expandability Either alternative can be designed to be expandable, provided that sufficient space is available. Operability and maintainability Either alternative can be readily operated and maintained. Public and political acceptability Outfall 051 is adjacent to residences. Alternative 1 could be implemented with a below-ground or a dual-use tank, providing higher public acceptance. Alternative 2 will require above-grade tanks and on-site chemical/disinfectant storage. Ability to integrate green solutions Either alternative can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs Either alternative is compatible with other MSD programs. If a regional tunnel is selected for controlling CSOs that discharge to the Mississippi River, the local CSO control option at Maline Creek should be reconsidered as it may be preferable to also store these flows in the regional tunnel. Table 8-2 Level 3 Evaluation of Maline Creek Alternatives Section 8.4 of this report describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. 8.3.2 Gingras Creek 8.3.2.1 Alternatives The Level 2 screening process identified three Integrated Control Alternatives for the single CSO discharging to Gingras Creek. These alternatives are shown on Figure 8-5. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-9 February 2011 Figure 8-5 Gingras Creek CSO - Integrated Control Alternatives Alternative 1 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Relocation of Bissell Point Outfall 059 such that it discharges into the Gingras Creek Branch of the Baden Trunk Sewer. Alternative 2 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • A below-grade storage tank to store overflow volumes from Bissell Point Outfall 059 to the desired level of control. Stored flows would be later bled back to the Baden Trunk Sewer for secondary treatment at the Bissell Point Treatment Plant. Alternative 3 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • A small CSO treatment unit to treat overflows from Bissell Point Outfall 059 to the desired level of control prior to discharge to Gingras Creek. SSES investigations recently identified three storm sewers that discharge into the combined sewer system from the area directly to the west of the combined sewer system. All three alternatives were evaluated with and without the separation of these three separate storm sewers. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-10 February 2011 8.3.2.2 Cost-Performance Analysis Regardless of the level of control, capital and total present worth costs for each alternative were determined to be lower when separation of the three storm sewers (mentioned above) was included in the alternative. All further comparison of the alternatives therefore includes the separation of these storm sewers. Cost-performance curves are presented in Figures 8-6, 8-7 and 8-8 for Alternatives 1, 2 and 3 respectively. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. The cost scales differ between the figures. Figure 8-9 compares the total present worth of the three alternatives. $0 $2 $4 $6 $8 $10 024681012 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-6 Gingras Creek Cost-Performance - Alternative 1 $0 $5 $10 $15 $20 $25 $30 024681012 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-7 Gingras Creek Cost-Performance - Alternative 2 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-11 February 2011 $0 $2 $4 $6 $8 $10 $12 024681012 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-8 Gingras Creek Cost-Performance - Alternative 3 $0 $5 $10 $15 $20 $25 $30 024681012 Average Number of Overflows per YearTotal Present Worth ($Million)Alternative 1Alternative 2Alternative 3 Figure 8-9 Gingras Creek Total Present Worth Comparison 8.3.2.3 Impact on Bissell Point Treatment Plant Alternative 1 relocates Outfall 059 to discharge directly to the Gingras Creek Branch of the Baden Trunk Sewer. No changes in peak or sustained flows to the Bissell Point Treatment Plant will result from implementation of this alternative. Alternative 2 includes the use of a tank to store flows from Outfall 059 until after the event, at which time the stored flows would be pumped back to the Baden Trunk Sewer. Peak instantaneous flows to the treatment plant do not change under this alternative. Sustained flows to the treatment plant increase Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-12 February 2011 modestly (up to 2.7 MGD, depending on the level of control) during the period when the storage tank is being drained. The increase in sustained flow to the treatment plant is well within the ability of the plant to provide secondary treatment and meet its operating permit requirements. Alternative 3 provides local treatment for the overflows from Outfall 059. No changes in peak or sustained flows to the Bissell Point Treatment Plant will result from implementation of this alternative. 8.3.2.4 Alternatives Evaluation Table 8-3 presents the evaluation of the three alternatives for the primary and secondary Level 3 evaluation criteria for the Gingras Creek CSO. Criteria Evaluation Cost (capital and total present worth) Alternative 1, outfall relocation, is less expensive than either Alternative 2, local storage, or Alternative 3, local treatment. Environmental benefit Alternative 1 eliminates the overflow to Gingras Creek. Alternatives 2 and 3, depending on the selected level of control, result in some untreated overflows to Gingras Creek. Alternative 3 results in both untreated and treated overflows to the creek. Technical feasibility Due to space limitations, the feasibility of Alternative 2, local storage, diminishes at higher levels of control (less than 6 overflows per year). Primary Adaptability, expandability All of the alternatives can be designed to be expandable. Operability and maintainability All of the alternatives can be readily operated and maintained. Public and political acceptability Outfall 059 is adjacent to an apartment complex. Alternative 1 would provide the highest level of public acceptability as no controls would be located at the outfall. Both Alternatives 2 and 3 will require tanks and equipment adjacent to this residential area. Alternative 2 could be implemented with a below-ground or a dual-use tank, providing higher public acceptance. Alternative 3 will require above-grade tanks and on-site chemical/disinfectant storage. Ability to integrate green solutions All of the alternatives can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs Alternative 1, outfall relocation, provides a benefit by reducing peak wet weather flows in MSD’s adjacent separate sewer system. Table 8-3 Level 3 Evaluation of Gingras Creek Alternatives Section 8.4 of this report describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-13 February 2011 8.3.3 Mississippi River 8.3.3.1 Alternatives The Level 2 screening process identified a single Integrated Control Alternative for the CSOs discharging directly to the Mississippi River, as shown on Figure 8-10. Figure 8-10 Mississippi River CSOs - Integrated Control Alternatives Alternative 1 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Continued operation and maintenance of the Bissell Point Overflow Regulation System to control the influence of Mississippi River stage on the interception of flows from the combined sewer system. • Separation of Significant Industrial Users: Anheuser-Busch and Mallinckrodt. • Full Utilization of Excess Primary Treatment Capacity at the Bissell Point Treatment Plant. • Maximization of Flow Pumping to the Bissell Point Treatment Plant. • Sewer Separation for Bissell Point Outfall 055. • CSO controls implemented on tributaries. • Tunnel storage of flow from CSOs to the Mississippi River located within the Bissell Point watershed. Stored flows would be later bled back to the Bissell Point Treatment Plant for secondary treatment. • Local storage tanks for CSOs to the Mississippi River located within the Lemay watershed. Stored flows would be later bled back to the Lemay Treatment Plant for secondary treatment. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-14 February 2011 8.3.3.2 Cost-Performance Analysis Cost-performance curves for Alternative 1 for the Mississippi River CSOs are presented in Figure 8-11. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. Note that the curves represent the costs and benefits only for additional controls to be installed after the planning process is completed and approved. The costs and benefits of controls that MSD has implemented during the planning process or is currently implementing are not included. $0 $500 $1,000 $1,500 $2,000 $2,500 $3,000 $3,500 $4,000 $4,500 $5,000 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-11 Mississippi River Cost-Performance 8.3.3.3 Impact on Treatment Plants Alternative 1 includes the use of a tunnel and local storage tanks to store flows from the CSOs to the Mississippi River until after the event, at which time the stored flows would be pumped to, and receive full secondary treatment at the Bissell Point and Lemay Treatment Plants. Peak instantaneous flows to the treatment plants do not change under this alternative. The storage tunnel dewatering pump rate was kept below a maximum of 125 MGD in order to limit peak sustained flows to the Bissell Point Treatment Plant to 250 MGD. This sustained flow represents the plant’s ability to provide secondary treatment and meet its operating permit requirements. This limitation results in maximum tunnel dewatering times of 2 days to 2 weeks at levels of control of less than 8 overflows per year, which increases the required tunnel storage volume up to 43 percent at the higher levels of control. Alternately, tunnel dewatering times could be shortened, and tunnel volumes reduced, if only primary treatment was provided for the stored flows. MSD did not investigate this option further as even the smaller tunnel sizes are unfeasible and unaffordable at high levels of control. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-15 February 2011 8.3.3.4 Alternatives Evaluation Table 8-4 presents the evaluation of Alternative 1 for the primary and secondary Level 3 evaluation criteria for the Mississippi River CSOs. Criteria Evaluation Cost (capital and total present worth) Capital and total present worth costs are very high (more than $1 billion) and increase significantly at a level of control of less than 6 overflows per year. Environmental benefit This alternative provides full secondary treatment of stored flows prior to discharge to the Mississippi River, except as noted below. Technical feasibility The practical limit of tunnel construction is met at a level of control of 6 overflows per year. More stringent control requires multiple parallel tunnels, an expensive and very time-consuming proposition. The practicality of providing full secondary treatment and keeping tunnel dewatering times to less than 48 hours is exceeded at a level of control of less than 8 overflows per year. Primary Adaptability, expandability Limited additional performance could be achieved by dewatering the tunnel/tanks more quickly and providing only primary treatment to some or all of the stored flows. Operability and maintainability This alternative can be operated and maintained. Public and political acceptability Governmental representatives and the public have both questioned the propriety of spending over $1 billion for this alternative, considering the impact of CSOs on water quality and the existing and attainable uses for the Mississippi River. Ability to integrate green solutions This alternative can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs See prior discussion of integrating local CSO control at Maline Creek into this solution. Table 8-4 Level 3 Evaluation of Mississippi River Alternatives Section 8.4 of this report describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-16 February 2011 8.3.4 Upper River Des Peres 8.3.4.1 Alternatives The Level 2 screening process identified a single Integrated Control Alternatives for the CSOs discharging to the Upper River Des Peres, as shown on Figure 8-12. Figure 8-12 Upper River Des Peres CSOs - Integrated Control Alternatives Alternative 1 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Continued operation and maintenance of the Skinker-McCausland Tunnel. • Tunnel storage of flow from CSOs to the Upper River Des Peres. Stored flow would be bled back to the Lemay Treatment Plant for secondary treatment as capacity became available. Partial sewer separation may be implemented where appropriate to reduce the costs for consolidation piping and tunnel storage. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-17 February 2011 8.3.4.2 Cost-Performance Analysis Cost-performance curves for Alternative 1 for the Upper River Des Peres CSOs are presented in Figure 8-13. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. $0 $50 $100 $150 $200 $250 $300 $350 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-13 Upper River Des Peres Cost-Performance 8.3.4.3 Impact on Lemay Treatment Plant Alternative 1 includes the use of a tunnel to store flows from the CSOs to the Upper River Des Peres until after the CSO event ceases, at which time the stored flows would be pumped to, and receive full secondary treatment, at the Lemay Treatment Plant. Peak instantaneous flows to the treatment plant do not change under this alternative. The storage tunnel dewatering pump rate was kept below a maximum of 10 MGD to limit flows to downstream conveyance systems. This limitation results in maximum tunnel dewatering times over 48 hours at levels of control of less than 8 overflows per year; tunnel sizes for these levels of control reflect the capped dewatering rate. The 10 MGD increase in sustained flow to the treatment plant is well within the ability of the plant to provide secondary treatment and meet its operating permit requirements. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-18 February 2011 8.3.4.4 Alternatives Evaluation Table 8-5 presents the evaluation of Alternative 1 for the Upper River Des Peres CSOs for the primary and secondary Level 3 evaluation criteria. Criteria Evaluation Cost (capital and total present worth) Capital and total present worth costs increase significantly at a level of control of less than 4 overflows per year. Environmental benefit This alternative provides full secondary treatment of stored flows, to the selected level of control. Technical feasibility Construction of any CSO controls in this highly residential area will be difficult. It may be necessary to mine the tunnel in two directions from a single construction shaft in Heman Park. Final design may indicate greater feasibility for local storage at some remotely-located CSOs, rather than conveyance to the tunnel. Primary Adaptability, expandability Additional performance could be achieved by dewatering the storage tunnel more quickly and implementing green infrastructure. Operability and maintainability This alternative can be operated and maintained. Public and political acceptability An underground tunnel is considered to be the most acceptable alternative of the options considered for this receiving stream segment, though issues may arise due to construction in congested residential areas. Ability to integrate green solutions This alternative can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs This alternative is compatible with other MSD programs. Table 8-5 Level 3 Evaluation of Upper River Des Peres Alternatives Section 8.4 of this report describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. 8.3.5 River Des Peres Tributaries 8.3.5.1 Alternatives The Level 2 screening process identified two Integrated Control Alternatives for the CSOs discharging to the River Des Peres tributaries (Claytonia, Hampton, Black and Deer Creeks). These alternatives are shown on Figure 8-14. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-19 February 2011 Figure 8-14 River Des Peres Tributaries CSOs - Integrated Control Alternatives Alternative 1 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Sewer separation of fifteen small CSOs: Lemay Outfalls 107, 108, 110, 112, 114, 115, 116, 141, 157, 160, 161, 164, 165, 174 and 175. • A tunnel sized for conveyance of flow from the remaining CSOs to a single location on the River Des Peres main channel. The CSO outfalls along the tributaries would be eliminated. The oversized conveyance tunnel would store flow to the desired level of control. Stored flow would be bled back to the Lemay Treatment Plant for secondary treatment as capacity became available. Alternative 2 includes the following CSO controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Sewer separation of the fifteen small CSOs, as listed above. • A tunnel sized for storage of flow from the remaining CSOs. The existing CSO outfalls would remain along the tributaries. Stored flow would be bled back to the Lemay Treatment Plant for secondary treatment as capacity became available. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-20 February 2011 8.3.5.2 Cost-Performance Analysis Cost-performance curves are presented in Figures 8-15 and 8-16 for Alternatives 1 and 2 respectively. The cost scales differ between the figures. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. Figure 8-17 compares the total present worth of the two alternatives. $0 $100 $200 $300 $400 $500 $600 $700 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-15 River Des Peres Tributaries Cost Performance - Alternative 1 $0 $50 $100 $150 $200 $250 $300 $350 $400 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-16 River Des Peres Tributaries Cost-Performance - Alternative 2 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-21 February 2011 $0 $100 $200 $300 $400 $500 $600 $700 024681012141618 Average Number of Overflows per YearTotal Present Worth ($Million)Alternative 1 Alternative 2 Figure 8-17 River Des Peres Tributaries Total Present Worth Comparison 8.3.5.3 Impact on Lemay Treatment Plant Both alternatives include the use of a storage tunnel to store flows from the CSOs to the River Des Peres Tributaries until after the CSO event ceases, at which time the stored flows would be pumped or drained to the storage tunnel located under the Lower and Middle River Des Peres, and receive full secondary treatment at the Lemay Treatment Plant. Peak instantaneous flows to the treatment plant do not change under these alternatives. The combined tunnel dewatering rate, considering CSO controls on the Lower and Middle River Des Peres and tributaries, will increase sustained flows to the plant above the existing secondary treatment capacity of 167 MGD at most levels of control investigated. This will require either an increase in secondary treatment capacity, or providing only primary treatment to some of the stored CSO flow. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-22 February 2011 8.3.5.4 Alternatives Evaluation Table 8-6 presents the evaluation of the two alternatives for the primary and secondary Level 3 evaluation criteria for the CSOs discharging to the River Des Peres tributaries (Deer, Black, Hampton and Claytonia Creeks). Criteria Evaluation Cost (capital and total present worth) Alternative 1 is significantly more costly than Alternative 2 for all levels of control. Environmental benefit Alternative 1 eliminates overflows to the tributaries under all levels of control, whereas some untreated overflows to the tributaries still occur under Alternative 2. The impact on the Lower River Des Peres is the same for both alternatives. Technical feasibility Both alternatives will pose technical challenges due to congested residential areas. Alternative 1 may prove to be unfeasible during final design due to the difficulty in locating significantly larger diameter conveyance pipes in these areas. Primary Adaptability, expandability Additional performance could be achieved under each alternative by dewatering the storage tunnel more quickly and implementing green infrastructure. Operability and maintainability Both alternatives can be operated and maintained. Public and political acceptability Both alternatives pose similar public acceptability issues due to construction in congested areas. Ability to integrate green solutions Both alternatives can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs Both alternatives are compatible with other MSD programs. Table 8-6 Level 3 Evaluation of River Des Peres Tributaries Alternatives Section 8.4 of this report describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-23 February 2011 8.3.6 Lower and Middle River Des Peres 8.3.6.1 Alternatives The Level 2 screening process identified three Integrated Control Alternatives for the CSOs discharging to the Lower and Middle River Des Peres. These alternatives are shown on Figure 8-18. Figure 8-18 Lower and Middle River Des Peres CSOs - Integrated Control Alternatives Each of the three alternatives includes the following controls: • The source control technologies and collection system controls previously identified in Section 7.3.2 as common to all alternatives. • Sewer Separation for Lemay Outfalls 046, 049, 062, 168 and 177. • Continued operation and maintenance of the Lemay Overflow Regulation System. • Continued operation and maintenance of the Skinker-McCausland Tunnel. • Full Utilization of Excess Primary Treatment Capacity at the Lemay Treatment Plant. • Repair of inflow sources to the flow interception system under the River Des Peres channel. • Upstream SSO and CSO Volume Reduction. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-24 February 2011 The CSO controls specific to each of the three alternatives are described below. Alternative 1 includes the following: • Construction of new CSO outfalls, diversion structures and interceptor sewers for the existing connections to the enclosed section of the River Des Peres under Forest Park. This allows CSO flows from these connections to be captured prior to mixing with storm flows in the enclosed portion of the River Des Peres, thereby resulting in a reduction in CSO volumes to be controlled. • A storage tunnel under the entire Lower and Middle River Des Peres system (i.e., the Lower and Middle River Des Peres open channels and the enclosed section of the River Des Peres in Forest Park). Stored flows would be bled back to the Lemay Treatment Plant as capacity became available. Alternative 2 includes the following CSO controls: • A storage tunnel under the Lower and Middle River Des Peres open channels. Both CSO and storm flows are controlled by the storage tunnel. Stored flows would be bled back to the Lemay Treatment Plant as capacity becomes available. Alternative 3 includes the following CSO controls: • Storage of wet weather flows in the enclosed portion of the River Des Peres (two 29-foot horseshoe sewers) under Forest Park. • A local treatment system adjacent to the Macklind Pump Station, using the pump station to convey flow to it. • A storage tunnel under the Lower and Middle River Des Peres open channel to capture remaining CSO flow up to the desired level of control. Stored flows would be bled back to the Lemay Treatment Plant as capacity becomes available. 8.3.6.2 Cost-Performance Analysis Cost-performance curves are presented in Figures 8-19, 8-20 and 8-21 for Alternatives 1, 2 and 3 respectively for the Lower and Middle River Des Peres CSOs. The curves show the estimated capital cost and total present worth cost for varying levels of control, expressed as the average number of overflows per year, based on typical year precipitation. Figure 8-22 compares the total present worth of the three alternatives. Note that the curves represent the costs and benefits only for additional controls to be installed after the planning process is completed and approved. The costs and benefits of controls that MSD has implemented during the planning process or is currently implementing are not included. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-25 February 2011 $0 $500 $1,000 $1,500 $2,000 $2,500 $3,000 $3,500 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-19 Lower and Middle River Des Peres Cost-Performance - Alternative 1 $0 $500 $1,000 $1,500 $2,000 $2,500 $3,000 $3,500 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-20 Lower and Middle River Des Peres Cost-Performance - Alternative 2 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-26 February 2011 $0 $500 $1,000 $1,500 $2,000 $2,500 $3,000 $3,500 024681012141618 Average Number of Overflows per YearCost (Million Dollars)Total Present Worth Total Capital Cost Figure 8-21 Lower and Middle River Des Peres Cost-Performance - Alternative 3 $0 $500 $1,000 $1,500 $2,000 $2,500 $3,000 $3,500 024681012141618 Average Number of Overflows per YearTotal Present Worth ($Million)Alternative 1Alternative 2Alternative 3 Figure 8-22 Lower and Middle River Des Peres Total Present Worth Comparison 8.3.6.3 Impact on Lemay Treatment Plant All three alternatives includes the use of a tunnel to store flows from the CSOs to the Lower and Middle River Des Peres until after the event, at which time the stored flows would be pumped to, and receive full secondary treatment at the Lemay Treatment Plant. Alternative 3 accomplishes some of the storage within existing sewers and supplements the storage with a small local treatment unit. Peak instantaneous flows to the Lemay Treatment Plant do not change under these three alternatives. The tunnel dewatering rates will increase sustained flow to the plant above the existing secondary treatment capacity of 167 MGD Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-27 February 2011 at most levels of control investigated (8 or fewer overflows per year). This will require either an increase in secondary treatment capacity, or providing only primary treatment to some of the stored CSO flows. 8.3.6.4 Alternatives Evaluation Table 8-7 presents the evaluation of the three alternatives for the primary and secondary Level 3 evaluation criteria for the CSOs discharging to the Lower and Middle River Des Peres. Criteria Evaluation Cost (capital and total present worth) Alternative 3 is the least costly alternative for all levels of control to the “knee of the curve” at 4 overflows per year. Costs for all alternatives escalate rapidly with increasing levels of control. Environmental benefit All three alternatives result in similar benefits for the River Des Peres. Technical feasibility All of the alternatives reach the practical limits of tunnel construction at a level of control of 3 to 4 overflows per year. More stringent control requires multiple parallel tunnels, an expensive and very time-consuming proposition. Primary Adaptability, expandability Limited additional performance could be achieved by dewatering the tunnel more quickly and providing only primary treatment to some or all of the stored flows. Operability and maintainability All alternatives can be operated and maintained. Public and political acceptability All three alternatives are approximately equal regarding public acceptability. MSD owns much of the right-of-way required for the project. The treatment unit in Alternative 3 would be located away from any residential area. Numerous CSO control structures (drop shafts and ancillary equipment) will be located along the existing River Des Peres channel. Ability to integrate green solutions All alternatives can be integrated with green infrastructure solutions. Secondary Compatibility with other MSD programs All of the alternatives are compatible with other MSD programs. Table 8-7 Level 3 Evaluation of Lower and Middle River Des Peres Alternatives Section 8.4, below, describes how the various evaluation factors noted above were considered in selecting the recommended CSO controls. 8.4 Selected Alternative The formulation of a recommended set of controls that will comprise the Long-Term Control Plan requires the consideration of a number of factors. Chief among these factors are the following: • Public and political acceptance of the proposed solutions. The public and local governments must believe that CSO controls have been sized and prioritized to meet the correct objectives and goals. • Total program cost and resulting user rates. Total program costs include not only the cost of new CSO controls, but also the cost of operating and maintaining existing system assets and the cost of other required capital improvements (e.g., treatment plants, sanitary sewer overflow control). • Existing controls. MSD has invested approximately $600 million (in 2008 dollars) to implement long-term CSO controls during the planning process; some of these controls are still being implemented. Refer to Section 3.2.6 for details of these existing controls. Significant benefits have resulted from this investment in CSO controls, reducing loadings significantly to the Mississippi River, Lower and Middle River Des Peres, and Maline Creek. Estimated annual system-wide CSO loading reductions are 38 percent volume, 62 percent BOD5, and 29 percent TSS. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-28 February 2011 • Costs versus benefits. The cost-performance analysis of additional controls on each receiving water segment defines the relationship between investment and resulting benefit. This analysis is critical in determining the most cost-effective means of reducing CSO volumes and pollutant loadings in attempting to meet Clean Water Act objectives and requirements. • The cascading effect of implementing controls. CSO controls on the Upper River Des Peres, for example, provide water quality benefits not only on that receiving water segment, but also on the Middle and Lower River Des Peres, and ultimately the Mississippi River. • Water quality gains. CSO discharges, and hence CSO controls, impact the various receiving waters in St. Louis differently, due to a very large range in base flows – less than 10 cfs for the smaller tributary streams to more than 150,000 cfs for the Mississippi River. Attainability of designated uses and associated water quality criteria vary between these receiving waters. • Treatment plant impacts. The impacts of various levels of CSO control on existing treatment plant performance must be considered, along with the ability of those plants to handle increased peak and sustained flows and still meet operating permit requirements. • Technical feasibility. In certain instances, practical limits have been identified on the degree of control that can be accomplished. MSD engaged their technical consultants and their public Stakeholder Advisory Committee to define CSO control scenarios that considered the results of the Level 3 Screening analyses in light of the above factors. Five scenarios were identified and are defined in detail below. Costs have been updated to late 2008, corresponding to the timeframe when the stakeholders and public began their considerations. Each of the five scenarios has two common elements that will be implemented throughout the combined sewer areas – the promotion of wider implementation of source controls such as street sweeping, litter control and proper waste disposal; and the use of green practices or green infrastructure to reduce stormwater runoff and encourage more natural ground infiltration. Common types of green infrastructure include green roofs, bioretention (e.g., rain gardens), green street techniques, green parking retrofits, rain barrels and neighborhood-scale stormwater retrofitting. The last technique may provide an opportunity to take advantage of vacant properties and underused properties owned by the Land Reutilization Authority. 8.4.1 Scenario 1 – Complete Elimination The complete elimination of CSOs, even though dismissed in the various Level 2 analyses, was chosen as a baseline (100 percent CSO control) to measure all other control scenarios against. This scenario would involve the separation of the combined sewer system into separate sanitary and storm sewer systems. All sewage would be captured for full treatment under this scenario. The current 65 percent capture of stormwater from the combined sewer system for treatment would be eliminated. The estimated total capital cost of Scenario 1 is $9.6 billion (in 2008 dollars). This cost represents only the cost of separating the public sewer system controlled by MSD. Individual property owners would be responsible for separating private sewers and plumbing systems. For example, homeowners would need to separate roof drains from their sanitary lateral and connect each source to the appropriate (sanitary or storm) public sewer system. Owners of commercial and industrial buildings with combined plumbing systems within the buildings would need to re-plumb the buildings and connect the separated plumbing to the appropriate separated sewer system. The cost of this private sewer separation is unknown and not included in the $9.6 billion estimated capital cost. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-29 February 2011 Additional considerations (advantages and disadvantages) identified during the consideration of Scenario 1 are listed below: Advantages • Eliminates pollution from CSOs to local streams. Disadvantages • Creates additional separation costs for property owners. • Increases stormwater pollution of local streams, since stormwater that is captured by the current combined sewer system would no longer be treated. • Significantly disrupts the community during construction. Every street would have to be torn up and all plumbing reconfigured. • Roughly doubles the infrastructure (sewers) to maintain in the future. 8.4.2 Scenario 2 – “Knee-of-Curve” Everywhere Scenario 2 is based upon providing CSO control on all receiving water segments to a level where further expenditures result in diminishing benefits (knee of the curve), as indicated in Table 8-8. For those receiving water segments with multiple control alternatives, the following explains the selected alternative: • Maline Creek. Local treatment at Outfall 051 and local storage at Outfall 052 (Alternative 2) was selected over local storage at both outfalls (Alternative 1). Alternative 2 has lower costs than Alternative 1. The treated overflows discharging to Maline Creek are acceptable as there is no known recreational use of this receiving water segment. • Gingras Creek. Outfall relocation (Alternative 1) was preferred over local storage (Alternative 2) and local treatment (Alternative 3) due to is lower cost and greater benefit. All CSOs to Gingras Creek are eliminated under Alternative 1. Alternatives 2 and 3 still entail some untreated overflows to the creek, depending on the selected level of control. Alternative 3 would entail both untreated and treated overflows to the creek. • River Des Peres Tributaries. Although it was the higher-cost alternative, Alternative 1 (conveyance/storage tunnel) was selected as it eliminated all CSOs to the tributaries. • Lower & Middle River Des Peres. Alternative 3 (tunnel storage coupled with in-sewer storage and local treatment) represented the lowest cost alternative at the desired level of control. Technical feasibility (tunnel and treatment plant sizing limitations) also weighed heavily in selecting the level of control, particularly for the CSOs discharging to the Mississippi River and Lower/Middle River Des Peres receiving water segments. The single CSO outfall to Gingras Creek would be relocated under this and all subsequent CSO control scenarios as this is the least cost and highest benefit solution for this CSO at all levels of control considered. Receiving Water Segment Control Alternative Level of Control1 Total Present Worth ($million) Maline Creek Alternative 2 – local treatment (Outfall 051) and local storage (Outfall 052) 4 39 Gingras Creek Alternative 1 – outfall relocation 0 6 Mississippi River Alternative 1 – storage tunnel 6 1380 Upper River Des Peres Alternative 1 – storage tunnel 4 200 River Des Peres Tributaries Alternative 1 – conveyance/storage tunnel 4 410 Lower & Middle River Des Peres Alternative 3 – storage tunnel, in-sewer storage, local treatment at Outfall 063 4 1140 Notes: 1 Defined as number of overflows in the typical year (year 2000). Table 8-8 CSO Control Scenario 2 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-30 February 2011 This control scenario provides a high level of control for all CSOs and increases the system-wide percent capture of combined stormwater and sewage from 65 percent to 92 percent for the typical year. Estimated total capital costs are $3.2 billion (in 2008 dollars). Additional considerations (advantages and disadvantages) identified during the consideration of Scenario 2 are listed below: Advantages • Highest benefit to Mississippi River compared to other feasible alternatives. • High benefit to smaller, urban streams. Disadvantages • Greatest monthly sewer bill cost compared to other feasible alternatives. 8.4.3 Scenario 3 – “Knee-of-Curve” on Urban Streams plus Enhanced Green Program on Mississippi River This scenario was developed due to concerns expressed by several stakeholders over the high cost of installing further controls on the CSOs that discharge directly to the Mississippi River. The concerns were based on a number of factors: • The high cost of CSO control compared to the benefits achieved by that control. • The fact that MSD had already expended $600 million in long-term controls, primarily focused on those same CSOs. • The existence of significant opportunities for implementing green infrastructure in the areas tributary to the Mississippi River, which might not be possible if all available funding was dedicated to constructing a CSO storage tunnel along the river. The areas tributary to the Mississippi River contain several features conducive to “green controls” being implemented on a larger scale than is possible in the rest of the combined sewer area. These features include large impervious parking areas that could be converted to green parking, and large amounts of vacant or abandoned property, particularly north of Interstate Highway 64. These features provide potential opportunities for green infrastructure to be implemented as these areas are re-developed. Scenario 3 therefore provides CSO control on the CSOs discharging to all receiving water segments, except the Mississippi River, to a level where further expenditures result in diminishing benefits, as indicated in Table 8-9. Receiving Water Segment Control Alternative Level of Control1 Total Present Worth ($million) Maline Creek Alternative 2 – local treatment (Outfall 051) and local storage (Outfall 052) 4 39 Gingras Creek Alternative 1 – outfall relocation 0 6 Mississippi River Enhanced green infrastructure program N/A 100 Upper River Des Peres Alternative 1 – storage tunnel 4 200 River Des Peres Tributaries Alternative 1 – conveyance/storage tunnel 4 410 Lower & Middle River Des Peres Alternative 3 – storage tunnel, in-sewer storage, local treatment at Outfall 063 4 1140 Notes: 1 Defined as number of overflows in the typical year (year 2000). Table 8-9 CSO Control Scenario 3 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-31 February 2011 The benefits of CSO control for the Mississippi River would thus be accomplished through: • The existing $600 million in controls already implemented or currently being implemented, and • The cascading water quality benefits of the CSO controls installed on the upstream urban stream segments. • Runoff and Mississippi River CSO volumes would be further reduced as a result of the implementation of green infrastructure as re-development opportunities arise. This control scenario provides a high level of control for CSOs on the urban or Mississippi River tributary streams, and increases the system-wide percent capture of combined stormwater and sewage from 65 percent to 82 percent for the typical year. Estimated total capital costs are $1.9 billion (in 2008 dollars). Additional considerations (advantages and disadvantages) identified during the consideration of Scenario 3 are listed below: Advantages • Lower costs preserve MSD’s ability to dedicate some funds in the future to “green” infrastructure. • Green controls will help preserve and restore natural landscapes and aid in stormwater management. Disadvantages • Mississippi River CSOs continue to discharge with relatively high frequency. • Long-term performance/benefit of green controls is not yet known. 8.4.4 Scenario 4 – Uniform Minimum Level of Control. This scenario was developed to determine what uniform level of control could be achieved at all CSOs, using gray infrastructure, for approximately the same total capital cost and user rates as under Scenario 3. Table 8-10 indicates the selected controls and level of control for the CSOs along each receiving water segment. Receiving Water Segment Control Alternative Level of Control1 Total Present Worth ($million) Maline Creek Alternative 2 – local treatment (Outfall 051) and local storage (Outfall 052) 18 17 Gingras Creek Alternative 1 – outfall relocation 0 6 Mississippi River Alternative 1 – storage tunnel 18 1040 Upper River Des Peres Alternative 1 – storage tunnel 18 160 River Des Peres Tributaries Alternative 1 – conveyance/storage tunnel 18 410 Lower & Middle River Des Peres Alternative 3 – storage tunnel, in-sewer storage, local treatment at Outfall 063 18 560 Notes: 1 Defined as number of overflows in the typical year (year 2000). Table 8-10 CSO Control Scenario 4 This control scenario provides a minimum level of control for all CSOs, including those discharging directly to the Mississippi River, and increases the system-wide percent capture of combined stormwater and sewage from 65 percent to 81 percent for the typical year. Estimated total capital costs are $2.2 billion (in 2008 dollars). Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-32 February 2011 Additional considerations (advantages and disadvantages) identified during the consideration of Scenario 4 are listed below: Advantages • Some level of CSO reduction is accomplished at all 199 CSO outfalls. Disadvantages • Significantly less benefit to smaller, urban streams than under other feasible options. • Slightly less benefit to Mississippi River (as measured by system-wide capture) for higher cost compared to other feasible options. • More difficult to expand controls, if necessary, in future due to minimum initial level of control provided. 8.4.5 Scenario 5 – Graduated Control on Urban Streams plus Enhanced Green Program on Mississippi River This scenario was developed to determine the costs and benefits of matching the level of control to stream size such that CSOs discharging to the smallest streams would receive the highest level of control and those discharging to larger streams would receive less control. The areas tributary to the Mississippi River would be included in an enhanced green infrastructure program in lieu of additional gray infrastructure controls for the Mississippi River outfalls. Scenario 5 is therefore very similar to Scenario 3, except that CSOs discharging to the Lower and Middle River Des Peres would receive slightly less control, as indicated in Table 8-11. Receiving Water Segment Control Alternative Level of Control1 Total Present Worth ($million) Maline Creek Alternative 2 – local treatment (Outfall 051) and local storage (Outfall 052) 4 39 Gingras Creek Alternative 1 – outfall relocation 0 6 Mississippi River Enhanced green infrastructure program N/A 100 Upper River Des Peres Alternative 1 – storage tunnel 4 200 River Des Peres Tributaries Alternative 1 – conveyance/storage tunnel 4 410 Lower & Middle River Des Peres Alternative 3 – storage tunnel, in-sewer storage, local treatment at Outfall 063 8 1040 Notes: 1 Defined as number of overflows in the typical year (year 2000). Table 8-11 CSO Control Scenario 5 This control scenario increases the system-wide percent capture of combined stormwater and sewage from 65 percent to 81 percent for the typical year. Estimated total capital costs are $1.8 billion (in 2008 dollars). Additional considerations (advantages and disadvantages) identified during the consideration of Scenario 5 are listed below: Advantages • Less strict controls on Lower and Middle River Des Peres net a $100 million savings in total capital costs. • This would preserve funding that could later be dedicated to “green” infrastructure/controls. • Green controls could help preserve and restore natural landscapes and aid in stormwater management. Disadvantages • Mississippi River CSOs continue to discharge with relatively high frequency. • CSOs to the Lower and Middle River Des Peres would, on average, discharge 4 more times per year than other scenarios where the level of control was 4 overflows per year. • Long-term performance/benefit of green controls is not yet known. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-33 February 2011 8.4.6 System-Wide Benefits of Control Scenarios A comparison of the benefits of the different control scenarios is presented below in Figure 8-23. Because the different scenarios employ differing levels of control, the typical year CSO volume was selected as the basis for comparing the scenarios. The hydraulic model baseline conditions (year 2006) are depicted as are the estimated CSO volumes prior to the implementation of any of the long-term CSO controls described in Section 3.2.6. The modeled volumes for the five different control scenarios are based on Level 3 screening results and therefore do not include any synergistic benefits that occur when the individual CSO control measures are combined into a complete CSO control system. Scenarios 3, 4 and 5 provide similar benefits in terms of remaining system-wide CSO volume. Figure 8-24 compares the scenarios, focusing on the benefit to urban streams (River Des Peres and its tributaries, Maline Creek and Gingras Creek). This comparison indicates that Scenario 3 provides greater benefit than scenarios 4 and 5. Scenario 3 provides a similar benefit to the urban streams as does Scenario 2. 0 5 10 15 20 25 Pre-Control Modeled Conditions Scenario 5 Scenario 3 Scenario 4 Scenario 2 Scenario 1Annual CSO Volume (billion gallons) Figure 8-23 Comparison of Scenarios - System-Wide Benefits 0 1 2 3 4 5 6 7 8 9 Pre-Control Modeled Conditions Scenario 4 Scenario 5 Scenario 3 Scenario 2 Scenario 1Annual CSO Volume (billion gallons) Figure 8-24 Comparison of Scenarios - Urban Streams Scenario 1 Complete elimination Scenario 2 “Knee-of-the-curve” everywhere Scenario 3 “Knee-of-the-curve” on urban streams + enhanced green program on Mississippi Scenario 4 Uniform minimum Level of Control Scenario 5 Graduated control on urban streams + enhanced green program on Mississippi Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-34 February 2011 Figure 8-25 compares the total capital cost for each control scenario to the system-wide benefit. The total costs include the $0.6 billion in controls already implemented or currently being implemented. Scenario 5 Scenario 3 Scenario 4 Scenario 1 Scenario 2 ModeledPre-Control 0 2 4 6 8 10 12 0510152025 System-Wide Annual CSO Volume (billion gallons)Total Capital Cost ($billions) Figure 8-25 Control Scenario Cost-Performance Comparison 8.4.7 Selected CSO Control Scenario Stakeholder Advisory Committee members and the general public were given an opportunity to learn about each of the five CSO control scenarios; carefully consider the cost, estimated user rate impact, benefits, and other considerations for each scenario; and provide their input to the selection process. The committee members and general public strongly believed that CSO control efforts should be focused on those receiving waters that are most impacted by CSO discharges and are close to where people live and play. Controls implemented on these streams, coupled with the controls that MSD has already implemented, will benefit the Mississippi River. Hence, the stakeholders and public preferred Scenarios 3 and 5, which focus efforts on controlling CSOs that discharge to the smaller urban streams, over Scenarios 2 and 4 which provide uniform levels of control for all CSOs. The River Des Peres system was of highest concern to respondents. The use of green infrastructure was also considered to be very important by the Stakeholder Advisory Committee members and the general public, particularly in areas with CSOs directly tributary to the Mississippi River where “gray infrastructure” CSO controls would not provide noticeable water quality improvements. CSO Control Scenario 1 was the least favored alternative, due to its very high costs and the significant amount of disruption during construction. The highest ranked alternative was Scenario 3, under which CSOs discharging to urban streams would be controlled to the knee of the curve, and an enhanced green infrastructure program would be adopted in the areas with CSOs tributary to the Mississippi River. This approach would focus green infrastructure efforts in the areas that have the most potential for redevelopment and where the most benefit could be achieved. Scenario 3 is the alternative selected for implementation under the Long-Term Control Plan. Section 9 of this report describes in detail the specific steps and results of MSD’s public and agency participation process, and how MSD took the information provided by the public into account in selecting controls and developing its Long-Term Control Plan. Section 10 presents an assessment of Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 8. ALTERNATIVES EVALUATION Page 8-35 February 2011 MSD’s financial capability to finance the selected alternative. Section 11 presents the details of the proposed controls, estimated water quality impacts, the implementation schedule and a post-construction compliance monitoring program. This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-1 February 2011 9. PUBLIC PARTICIPATION 9.1 Introduction Public participation has been critical to MSD’s development of its Long-Term Control Plan. Since August 2007, MSD has implemented an extensive public participation program designed to generate meaningful community involvement in its planning process. As part of this program, the District has undertaken public outreach and education activities; maintained open lines of communication with affected stakeholder groups and the public at-large; and provided multiple opportunities for community input on the plan’s CSO reduction approach. MSD’s goal in executing these efforts was to obtain the public’s informed support of its control plan and the wet weather controls it proposed. In addition, MSD has used its public participation program as a platform for making the community more aware of the important role it plays in protecting the region’s water quality. Generating public support for CSO reduction has required MSD to raise the public’s awareness of and interest in sewer overflows, their water quality impacts, and various overflow controls. The District has also sought to deepen the public’s understanding of the environmental benefits and rate implications of the different control options. These efforts have helped to make the public more informed, which has enabled MSD to solicit constructive public input on the most appropriate wet weather controls for the St. Louis community. MSD has implemented its public participation program in four overlapping phases: research, situational analysis, outreach and education, and public input and involvement. In the first phase, the District reviewed the public engagement practices of municipalities across the U.S. to aid in its process design. It then met with a cross-section of St. Louis stakeholders to learn more about the water quality interests and concerns of local populations. Stakeholders also revealed effective strategies for involving these populations in the long-term planning process. The information obtained from MSD’s research and situational analysis helped shape the last two phases of the public participation program. In these phases, MSD conducted numerous communications activities and person-to-person interfaces with stakeholder groups, community representatives and finally the community at-large. Detailed descriptions of the specific activities performed in each phase are presented in the remainder of this chapter and its corresponding appendices. 9.2 Research Prior to the formal launch of its public participation program, MSD examined the community education and involvement processes of other municipalities addressing CSOs, including places like Portland, Seattle, Indianapolis, Kansas City, Atlanta, Northern Kentucky and the District of Columbia. From September to November 2007, the District analyzed the assorted approaches, methods and materials developed by these communities, incorporating suitable elements into its program design. It then organized a half-day public engagement workshop to introduce its entire team to the logic and activities of its public participation program. MSD also hired a leading expert on public involvement in wet weather programs to discuss best practices at the workshop and to provide episodic consulting on its program implementation. INFORMED SUPPORT Promote Understanding Solicit Input Generate Interest Raise Awareness Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-2 February 2011 9.3 Situational Analysis – Understanding Public Interests MSD spent the end of 2007 and the beginning of 2008 identifying stakeholders and stakeholder groups that could 1) shed light on the public’s water quality interests and concerns; and 2) provide insight on how to engage constituencies with varying levels of interest in CSO reduction. The District captured these insights through a series of stakeholder interviews and subsequently used the findings to refine its public participation program. 9.3.1 Stakeholder Interviews 9.3.1.1 Purpose & Composition From January to May 2008, MSD’s project team conducted face-to-face interviews with 21 stakeholders representing business, community, environmental, municipal, public health and regional planning entities (see Figure 9-1). Usually an hour in length, these interviews gave the team an opportunity to explain existing sewer conditions, sewer overflows – both CSOs and SSOs, the District’s long-term planning efforts, and the need for public involvement. Although the interviews were partly informative, their focus was on obtaining stakeholders’ responses to 12 questions that covered six major topics or themes. These included: • Concerns about the region’s water quality • Facilitators of planning success • Popular waterway uses and desires • Barriers to planning success • Expectations of MSD • Generating public interest and involvement The team used stakeholders’ intelligence and insights to become more aware of public perceptions and trends, and to better respond to the community’s interests. (See Appendix K for summaries of each stakeholder interview.) 9.3.1.2 Synopsis of Findings / Input Water Quality Concerns Most stakeholders said they were concerned that sewer overflows are undermining the region’s environmental and public health. They maintained that the affected waterways have difficulty supporting a wide variety of aquatic life and are less safe for people to experience. There were further concerns that noxious smells, floating trash and debris, and untreated human waste limit the public’s recreational use and enjoyment of the water bodies. Stakeholders worried that MSD might not consider these use impacts and environmental hazards to be as important as containing the control plan’s cost. Popular Waterway Uses & Desires The project team interviewed some stakeholders who frequently biked and hiked near or boated on area waterways. Team members also met with those who rarely, if ever, used local waterways for recreational purposes. Though the two groups’ experiences diverged, they generally agreed that St. Louis residents were developing a more user-oriented relationship with their rivers and streams. Many have become desirous of more opportunities for outdoor recreation along local greenways and waterways as major quality of life enhancements. Recognizing this, stakeholders wanted MSD to develop a control plan that would result in clean, safe and accessible waterways capable of supporting dependent ecosystems and increasing recreational use. 5 56 1 1 3 Business Community Environment Municipal Public Health Regional Figure 9-1 Stakeholder Interviews by Organizational Type Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-3 February 2011 Expectations Of MSD In order for the long-term planning process to gain sufficient community involvement and support, stakeholders stated that MSD would have to conduct a strong outreach and education effort. They expected that the District would communicate with the public and critical stakeholder groups frequently regarding the controls being considered, their associated costs, and the community’s likely contributions. Along with this, they wanted MSD to establish a transparent decision-making process that would incorporate community input into key project decisions and provide a public accounting of how those decisions were made. Stakeholders also expected MSD to develop a control plan that would achieve compliance with state and federal mandates in a way that the region could afford. For them, this meant having the District 1) intensify ratepayers’ involvement in stormwater and pollution management; 2) balance pollution reduction with cost containment; and 3) use some of its debt capacity to fund water quality improvements. In addition, stakeholders expected MSD to anticipate future environmental regulations and to select wet weather controls that would help meet those regulations. Facilitators Of Planning Success Most of the individuals interviewed agreed that the convergence of the control plan’s multi-billion dollar price tag and the public’s lack of sewer system knowledge was likely to undermine community support for needed improvements. While they conceded that MSD might not be able to completely overcome this, they thought that an awareness campaign that emphasized the importance of clean water to environmental and community health, and that promoted better habits among the public may be able to lessen the resistance. They also maintained that the District would achieve greater success if it connected the control plan to existing water conservation efforts; positioned both MSD and the public as responsible for protecting water quality; and focused on the end game – the development of an environmentally sustainable region. Barriers To Planning Success Stakeholders identified three major barriers to the control plan’s success. The first was the community’s lack of familiarity with wastewater processing and treatment, environmental technologies, and regulatory requirements. As a consequence, the public has a limited understanding of why sewer overflows matter. The second major barrier was public skepticism about MSD’s stewardship and priorities. This was in part an extension of popularly held anti-government sentiments. But, it also reflected a sense that the District has been reactive in its systems improvements; was slow to adopt a watershed approach to protecting water quality; and preferred gray solutions to a combination of smaller, greener ones. The last significant barrier was a pervasive anti-tax agenda that arises whenever rate increases are discussed in the public domain. Stakeholders noted that this agenda is partly a response to difficult economic conditions. However, they also contended that it derives from a history of low wastewater and stormwater rates that have obscured the real costs of water quality protections. Generating Public Interest and Involvement The barriers to long-term planning revealed to interviewees the need for public interest and involvement in MSD’s control plan. Stakeholders asserted that the District could heighten public participation by framing the protection of local waterways as not just its concern, but as everyone’s concern. Recognizing this, they felt MSD’s education efforts should stress the importance of the community’s input and actions to the development of viable solutions. Stakeholders also recommended that MSD use direct and indirect engagement strategies to reach out to members of the public. In terms of direct engagement, they suggested going to pre-existing stakeholder and community meetings to share information about the planning process. This would be essential given people’s limited knowledge of CSOs and their water quality impacts. They also proposed regular Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-4 February 2011 meetings with stakeholders that would keep the lines of communication open as well as the involvement of key stakeholders in public outreach and education. Broader public participation could be achieved through open houses, fun forums on water conservation, and special children’s initiatives since they would be affected by the plan’s multi-generational scope. With regard to indirect engagement, stakeholders encouraged MSD to employ an assortment of communications vehicles, including a project video, website, media coverage (print, radio, television and electronic), paid advertising, and mass mailings. 9.4 Outreach & Education Much of what came out of the stakeholder interviews was incorporated into the project team’s branding and outreach activities. MSD formed its project identity, collateral materials and even its planning goals in response to stakeholders’ insights. The following section offers a review of the District’s different outreach and education endeavors. 9.4.1 Project Branding & Planning Goals From the outset of its public participation program, MSD realized the importance of project branding as a means of generating increased public interest in its long-term planning process. In January 2008, it developed a graphic identity for the program that made use of compelling visual cues and resonant messages to appeal directly to community members’ values. Its goal was to create a project identity that immediately established the relevance of its control plan and helped to demystify its sewer operations, which remain largely invisible to the rate paying public. A number of considerations influenced the development of MSD’s program brand. The District wanted a unique identity that concisely communicated: 1) the regional nature of its planning activities, i.e., multiple communities are impacted; 2) the program’s focus on people and the environment, not just underground infrastructures; and 3) the quality of life improvements that would ensue as a result of planning. MSD also wanted to draw attention to the public’s desired outcomes like clean waterways, working sewers and healthy communities. The District’s branding efforts led to the creation of the Clean Rivers Healthy Communities Program (simply referred to as Clean Rivers). The program’s logo and tagline were designed to convey its environmental significance, positive human impact and infrastructure focus. Together, they form an identity that is free of technical jargon and easy for the public to understand. The identity is also broad enough that the District’s SSO and stormwater initiatives can later be placed underneath its brand umbrella without modifications to the image or message. All project materials distributed to the media, stakeholders and the public, contain the Clean Rivers brand. Along with the brand, they highlight the program’s three planning goals, which are to: 1) reduce the amount of sewage that overflows into waterways during moderate to heavy rainstorms; 2) involve more citizens in MSD’s pollution and stormwater control efforts; and 3) support environmentally friendly practices that encourage sustainable growth. Like the brand, the program’s goals help the public to quickly understand Clean Rivers’ environmental purpose and social relevance. Protecting Our Environment Through Sewer Improvements Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-5 February 2011 9.4.2 FAQ, Fact Sheet, Brochure With a clear brand and goals in place, MSD was able to develop and disseminate collateral materials that explained the Clean Rivers Program, sewer overflows, and the public’s role in water quality protection. Materials like the FAQ (frequently asked questions), program fact sheet and brochure served as key sources of project information and thousands were circulated throughout the planning process at public meetings, presentations and open houses. Stakeholder organizations like North County Inc. and St. Louis County also placed the documents at their area offices and shared them with their constituents. In addition, the FAQ provided the conceptual framework for the program’s website, helping the public easily find answers to its most common queries. An electronic copy of the brochure was also posted on the website so that it could be readily viewed and downloaded. 9.4.3 Video In the summer of 2008, MSD produced a ten-minute video to help the public understand combined sewer overflows and the long-term planning process. It featured members of Clean Rivers’ stakeholder advisory committee and MSD’s leadership talking about CSOs’ causes and effects as well as the need for stricter stormwater and pollution controls. To ensure message consistency, the video covered the same basic content as the FAQ. It was shot in a digital format so that it could be shown on DVD at community presentations and open houses, and uploaded to the website for independent viewing. A copy of the video was also posted on You Tube to help reach a wider audience. 9.4.4 Website The Clean Rivers website (www.cleanriversstl.com) was launched in August 2008 as the electronic home for the Long-Term Control Plan – a cyber address that anyone can visit to learn about the planning process. With 44 pages of content, visitors use the site to review the program’s background information and collateral materials; watch the project video; find out about public engagement events and presentations; access meeting records; and contact the project team. At the project’s conclusion, they will also be able to read and download the final control plan. To date, the website has had more than 2,700 unique visitors1, with the average visitor having viewed the site two times within a single reporting period (reports are generated monthly). While logged in, visitors have browsed an average of nine pages of content. Between March and May of 2009, visitors viewed more content for longer periods of time as indicated by the corresponding bandwidth metric. This occurred because additional materials were uploaded to the site for the spring open houses and event publicity drove site traffic up. During this same period, the average number of website hits almost quintupled. It should be noted, however, that the number of hits a site receives does not reflect its number of visitors, but rather the number of times its web server is accessed.2 More detailed website statistics are provided in Table 9-1 below. 2008 2009 Aug 1 to Dec Jan Feb Mar Apr May June July (to 7/24) Totals To Date Unique Visitors 631 142 178 582 548 290 246 144 2,761 Visits 1,232 207 275 904 863 466 367 252 4,566 Page Views 10,469 938 1,044 4,745 3,911 3,089 1,114 858 26,168 Hits 72,482 5,409 6,195 34,178 31,046 19,569 779 4,137 173,795 Bandwidth (MB) N/A 189 297 1,556 1,219 5,325 772 489 N/A Table 9-1 CRHC Website Statistics 1 Unique visitors are measured as separate connections from a visitor’s computer to the website’s server and generally reflect the number of different visitors to the site. 2 A hit on the web server can be a graphic, java applet, html file, etc. So, if a site has 79 small graphics on a page, every visitor to the site registers as 80 hits on the server (79 graphics plus the html file). Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-6 February 2011 7 10 5 1 33 2 Business Community Environmental Legislative Municipal Professional Table 9-2 Presentation Comments by Type 9.4.5 Community Presentations 9.4.5.1 Purpose & Composition MSD made 58 presentations on the Clean Rivers Program to municipal officials, stakeholder organizations and community groups between March 2008 and June 2009. By going into the community to conduct these presentations, the District’s team was able to share important project information with the public, answer pressing questions, and obtain feedback on the program’s activities and impacts. It was also able to gain exposure to a wider group of people than those who would normally self-select to attend one of its project meetings or open houses. As a consequence, the team presented to nearly 1,400 residents, including 212 elected officials. Presentations were made to municipalities (with a concerted effort to engage those that have combined sewers), business chambers and associations, environmental organizations, community interests and professional groups. The team also conducted a legislative briefing for U.S. congressional delegates and Missouri state representatives and senators who represent local ratepayers. An analysis of presentations by type is shown in Figure 9-2. Those who attended the presentations and briefing were given an 18-page PowerPoint handout that explained the sewer system, CSOs, the control plan, and the different ways the public can help protect water quality. Pamphlets on stormwater and pollution controls were also distributed at the end of each 20-minute address. (See Appendix L for a copy of the presentation, an attendance record, and a log of the public’s comments and questions.) 9.4.5.2 Synopsis of Findings The team fielded close to 250 comments and questions from officials and residents in attendance at its presentations. Their interests varied widely, but records of their feedback reveal more than a dozen topics that were repeatedly referred to as matters of import. The most common among these concerned attendees’ desire for a deeper understanding of the Clean Rivers Program, green options, flooding and backups, and CSO Costs. A list of popular topics and the frequency with which they were mentioned are captured in Table 9-2 below. Focus of Comment / Question Frequency Mentioned Focus of Comment / Question Frequency Mentioned • Project Understanding 42 • Incentive Programs 9 • Green Options 27 • Pollution Controls 9 • Miscellaneous 23 • User Rates 8 • Flooding & Backups 21 • Regulatory Compliance 7 • CSO Costs 19 • Environmental Impacts 7 • Stormwater Charges 18 • Customer Service Issues 7 • Public Engagement 17 • Other (topics with 3 or less mentions) 6 • Development, Planning & Zoning 15 • Receiving Streams 5 • CSO Controls 10 • Downspouts 4 Note: Several comments / questions referred to more than one topic and were therefore counted more than once. Figure 9-2 Community Briefings / Presentations by Type Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-7 February 2011 Additional presentations will continue to be scheduled throughout the planning process and beyond. In August and September of 2009, MSD will present to the American Public Works Association and to non-English speaking ratepayers from the Vietnamese and Bosnian communities. 9.4.6 Media For MSD, getting the media to understand the need for sewer system improvements and CSO reduction was important to the success of the public participation program. As one of the District’s stakeholders, the media serves as a key connector to various population segments and the community at-large, and is often their primary source of news and information. The media has given a steady stream of attention to MSD’s rates and operations since the beginning of the long-term planning process, but its focus on the Clean Rivers Program commenced in earnest in the spring of 2009 with the scheduling of the program’s public open houses. Driving this interest was the District’s outreach through occasional press releases, underground tours of its sewer facilities, and editorial briefings with the staffs of local on-line and print publications. The ensuing exposure resulted in multiple media appearances by District spokespeople and substantive coverage of the CSO issue. Sewer Tour On March 16 and 17, 2009, MSD hosted two media tours of its Macklind Pump Station and Outfall 063, the largest outfall in its combined sewer system. Reporters from STL-TV (City Cable), KTVI- TV/Channel 2, KMOV-TV/Channel 4, KSDK-TV/Channel 5, the St. Louis Post Dispatch and the West End Word experienced sewer infrastructure conditions and CSO discharges firsthand (it rained during one of the tours), giving them a better understanding of CSOs’ water quality impacts. They also heard briefly from members of the project team about the control plan’s purpose, likely public cost (i.e. billions not millions), and impending open houses. KMOV-TV, KTVI-TV, the St. Louis Post Dispatch and the West End Word subsequently ran stories about their sewer experiences, the District’s CSO issue and the opportunities for public involvement. Editorial Briefings To help ensure that the media understood the importance and magnitude of the control plan, MSD conducted editorial briefings with the staffs of the St. Louis American, St. Louis Beacon, St. Louis Post Dispatch and Suburban Journals from late March to early April 2009. These sessions allowed team members to delve more deeply into the specifics of the planning process and included discussions of the types of control options being considered, the different funding sources available, important project milestones, the team’s planning timetable and open house logistics. Project materials like program fact sheets and press releases were sent to the editorial staffs in advance of the meetings. Media Appearances & Coverage MSD’s outreach to media outlets yielded a number of television and radio appearances for its team members. In addition to the more than 10 minutes of air time that KMOV-TV and KTVI-TV spent reporting on sewer overflows, District spokespeople were interviewed live on local talk radio shows. These individuals spoke with news talk listeners on KMOX, largely African-American audiences on Majic 104.9’s Sunday Morning Live and Foxy 95.5’s Niecy Davis Show, and environmental enthusiasts on KDHX’s “Earthworms” with Jean Ponzi. Print outlets also interviewed project team members with Outfall 063 Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-8 February 2011 stories on Clean Rivers, CSOs and the open houses running twice in the Suburban Journals, four times in the St. Louis Post Dispatch, once in the West End Word and on-line in the St. Louis Beacon. 9.5 Public Input & Involvement MSD’s outreach and education efforts helped to create a more informed public that could 1) participate meaningfully in the long-term planning process; and 2) give valuable input on the CSO control options most likely to be supported by ratepayers. Through its development of an advisory group, two telephone surveys, open houses, a telephone information line, and a project email address, the District provided multiple forums for the public to share its preferences, concerns and desires. Both the forums and the public input obtained from them are described in the following sections. 9.5.1 Stakeholder Advisory Committee (SAC) 9.5.1.1 Purpose & Composition While the stakeholder interviews and community presentations enabled MSD to have intermittent interactions with groups and individuals affected by sewer overflows, the District wanted a public participation vehicle that would foster long-term stakeholder involvement in the Clean Rivers Program. To help it achieve this goal, MSD established a 12-member Stakeholder Advisory Committee (SAC) comprised of municipal, public health, environmental, regional, business and community representatives. Organizations with members currently on the SAC are identified in Table 9-3. Member Organization Classification Member Organization Classification • St. Louis City, Board of Public Service Municipal • StreamTeach, Inc. Environmental • St. Louis City, Public Health Department Public Health • Great Rivers Greenway District Regional • St. Louis County, Dept. of Highways and Traffic Municipal • East West Gateway Council of Governments Regional • River Des Peres Watershed Coalition Environmental • Civic Progress Business • Urban Farming STL Environmental • St. Louis University, Center for Environmental Education/Training Environmental • Area Resources For Community & Human Services Community Note: The appointment of ACORN to MSD’s Rate Commission reduced the size of the SAC from 12 to 11 members. Table 9-3 SAC Organizations The SAC has met six times to review, discuss and help shape MSD’s CSO reduction efforts since January 2008. Members have worked with the project team to: • Review program data and technical findings; • Increase awareness of and support for the Clean Rivers Program; • Advance the team’s knowledge of stakeholder groups’ interests and priorities; and • Serve as points of connection to the larger community. In short, the SAC has been a critical sounding board for the project team, helping to inform its understanding of not only the community’s values, but also its quality of life concerns and aspirations. (See Appendix M for an SAC member roster and for summaries of each SAC meeting.) Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-9 February 2011 9.5.1.2 Synopsis of Findings / Input The content of the SAC meetings and the feedback solicited from committee members grew increasingly complex between January and December of 2008. The first three meetings were informational in nature, exposing members to MSD’s sewer system and useful planning data. At the kick-off meeting, the committee learned about the history of the sewer system and sewer overflows, the public participation program, and SAC roles and responsibilities. The second meeting consisted of a four-hour, seven site tour of District operations and CSO outfalls. From the tour, members witnessed the unique challenges facing the Mississippi River and River Des Peres. They also saw CSO outfalls that discharge in parks, near large industrial sites, and in homeowners’ backyards. The third meeting provided more information on the conditions of local receiving streams. Members’ learned about the state’s designated use classifications, common waterway uses, and the federal regulations guiding the planning process. They also examined water quality findings for each receiving stream and reviewed the likely impacts of CSO reduction on stream quality based upon modeling data. Waterway Priorities The first three meetings prepared SAC members to establish their waterway priorities in meeting four. At this meeting, the project team discussed CSOs’ impacts on human health and aquatic life. Members then used this data to identify the receiving streams they thought should have the strictest levels of control. Their priorities are summarized in Table 9-4. Receiving Stream Priority Ranking SAC’s Rationale Upper River Des Peres First • CSO volume is large when compared to stream flow • Area is largely residential, with many opportunities for public contact Lower & Middle River Des Peres Second • A number of adjacent trails and parks are located along the river • River meets water quality standards less than half of the time • CSO volume is large when compared to stream flow River Des Peres Tributaries Second • Area is largely residential • CSO volume is significant compared to stream flow Gingras Creek Third • Has only one CSO outfall • Runs through a mostly residential community and is near a school Maline Creek Fourth • Affected part of the creek is largely inaccessible to the public • CSO volume is small when compared to stream flow Mississippi River Fifth • Work done on the other waterways benefits the river • River is largely bounded by industrial and commercial uses in the city with limited public access • CSO volume is small when compared to stream flow Table 9-4 SAC Waterway Priorities After ranking the waterways, SAC members assessed the costs and benefits of CSO reduction for each receiving stream. They used this information to better understand the implications of different control scenarios, which they explored at greater length in meeting five. SAC Members On Tour Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-10 February 2011 Preferred Level Of Control & Additional District Actions At the fifth SAC meeting, held in December 2008, committee members studied possible control options for each water body and analyzed various level of control (LOC) scenarios. Each scenario set a goal for the annual number of overflow events on all receiving streams and then estimated the capital costs associated with achieving that goal. The team originally presented the SAC with three scenarios to consider, but at the end of the fourth meeting members requested additional “green” scenarios that offered alternatives to building a billion dollar “gray” control along the Mississippi River. In response to this feedback, the team developed two scenarios that would install comprehensive green infrastructure to improve water quality in the Mississippi River. The SAC evaluated a total of five scenarios with members identifying the LOCs they thought would be best and worst to implement. Their findings and rationales are presented below in Table 9-5. Level Of Control Scenario SAC’s Rationale Best Scenario To Implement Knee-of-Curve on Urban Streams + Green on Mississippi River: 82% Wet Weather Capture This option: • Is among the least costly, though it still represents a significant burden to ratepayers. Provides most impact per dollar invested and per customer payment • Imposes sufficient overflow restrictions • Implies voluntary changes that may have other benefits e.g. green infrastructure • Necessitates ongoing citizen participation and education around green behaviors and policies • Requires research on the evaluation of green practices that will likely result in the identification of best practices • May be the easiest to “sell” to the public as best for a large urban area Worst Scenario To Implement Complete Elimination Through Sewer Separation: 100% Wet Weather Capture This option: • Is desirable, but will impose too much of a financial burden on ratepayers • Will not give ratepayers value improvements for the cost required • Ignores voluntary changes that might have other benefits ex. green infrastructure • Would result in ratepayer rebellion • Could possibly be achieved in the future by different means and technologies Table 9-5 Stakeholder Advisory Committee’s CSO Control Scenario Prioritization Following their scenario prioritization, SAC members identified additional actions they wanted MSD to take to enhance the control plan’s effectiveness. They recommended that the District: • Involve the public (property owners, developers, municipalities etc.) in its water quality improvement efforts through the promotion of sustainable green practices. They suggested MSD conduct intensive public education on these practices and create a formal green program that supports and/or subsidizes public action. • Build value-added benefits into its control plan so that the public sees positive, tangible changes along the affected waterways. Since changes in water quality are often difficult for the public to recognize, they proposed that MSD not only construct new controls, but that it also make receiving streams more aesthetically pleasing and/or user-friendly. • Set aside some plan implementation dollars for research on effective green infrastructure. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-11 February 2011 • Work more closely with municipalities to establish stricter ordinances and greater adherence to green development practices. • Intensify and strengthen partnerships with other impacted stakeholders, especially local environmental interests. A sixth SAC meeting was held in late August 2009. During this meeting, the project team discussed its open house findings and the District’s submittal of its CSO control plan to federal and state regulators. 9.5.2 Telephone Surveys 9.5.2.1 Purpose & Methodology In late March 2009, prior to MSD’s hosting of its open houses, ETC Institute conducted a public opinion survey of slightly more than 900 households in the region. The sample size was statistically significant with a 95% confidence level and a precision of ±3.5%. The 17-question survey was designed to measure ratepayers’: • Perceptions about the quality of St. Louis area waterways; • Knowledge about pollution sources and those responsible for waterway protection; • Willingness to perform stormwater and pollution control activities; and • Tolerance of rate increases associated with implementing the control plan. To measure the change in attitudes and perceptions regarding stormwater and pollution controls and rate affordability, ETC Institute administered a follow-up opinion survey in July 2009. With 7% fewer households (835) surveyed, the sample size remained statistically significant with a 95% confidence level and a precision of ±3.5%. With the exception of one question, this survey was exactly the same as the survey conducted prior to MSD’s hosting of the open houses. The revised question dealt with the public’s knowledge of the Clean Rivers Program and its purpose. (See Appendix N for the complete findings of both surveys.) ETC Institute also performed a t-test, a statistic to measure the variability between both sets of survey results. If the percentage responding on the second survey was ±4%, then the difference was considered statistically significant. 9.5.2.2 Synopsis of Survey Findings / Input Water Quality Perceptions & Knowledge Pre-Survey Nearly 40% of opinion poll respondents stated that the quality of St. Louis’ creeks and rivers has remained the same over the past few years. Respondents attributed water pollution to a variety of sources, including: factory and industrial discharges (33.7%), rainwater runoff (24.1%), and sewer overflows (26.2%). Although protecting local waterways from pollution is a shared responsibility, only one-third (32.7%) of respondents held this viewpoint. The majority (44.5%) felt that MSD and/or the water company (City of St. Louis Water Division or Missouri American Water) were responsible for protecting local water quality. Post-Survey In the second survey, nearly 45% of respondents stated that the quality of St. Louis’ creeks and rivers has remained the same. There was no significant change regarding water pollution sources. Again, the majority (46.9%) of the post-group respondents felt that MSD and the respective water companies were responsible for protecting local water quality. Significantly fewer respondents (27.4%) stated that all Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-12 February 2011 stakeholder groups – residents, businesses, municipalities, the water companies and MSD, share the responsibility of waterway protection. Willingness To Implement Stormwater & Pollution Controls Pre-Survey To reduce the amount of pollutants entering St. Louis’ waterways, residents are “very willing” to pick up litter (78.8%); pick up pet waste (53.4%); return excess fertilizer and cut grass to lawns from paved surfaces (59.2%); dispose of household hazardous waste at community collection sites (63.8%); change car washing practices (52.5%) and use low phosphorus fertilizers (37.4%). However, many stated that they are “not willing” to replace concrete and asphalt driveways and/or paths with pervious materials (46.9%). When asked about the use of rain gardens and rain barrels, nine of ten respondents stated they were not using either. Of those who did not have a rain garden or use a rain barrel, 49% and 56% respectively, the primary reason given was their not knowing that these strategies could reduce stormwater runoff and water pollution. Though most respondents are not currently using green strategies, 82% agreed that “MSD should include green infrastructure and other environmentally-friendly practices in its sewer and water quality improvement efforts.” Post-Survey Post-survey respondents are more willing to perform at least four of the nine stormwater and pollution control remedies offered. Specifically, they were more likely to pick up litter (85.4%); pick up pet waste (61.3%); return excess fertilizer and cut grass to lawns from paved surfaces (66.6%); and dispose of household hazardous waste at collection sites (69.3%). Slightly more (50.7%) than in the pre-survey were unwilling to replace concrete and asphalt driveways and/or paths with pervious materials, a control that has extensive cost implications. Regarding rain gardens and rain barrels, the same percentage indicated that they were not using either. However, the number of respondents stating that they had not considered a rain garden or rain barrel dropped significantly to 42% and 50%, respectively. In addition, a larger percentage of those surveyed (85% as compared to 82%) agreed that “MSD should include green infrastructure and other environmentally-friendly practices in its sewer and water quality improvement efforts.” Tolerance Of Rate Increases Pre-Survey On the whole, respondents were not amenable to a significant increase in their monthly sewer rate. Almost four out of ten (39%) people surveyed stated that a rate increase of $35/month would be “very difficult” to afford; and slightly less, 3.6 out of ten (35.8%), maintained that a $35 rate increase would be “difficult.” Taken together, almost three out of four respondents said that a $35 rate increase would be difficult to absorb. Figure 9-3 captures perceptions of affordability for a $35, $55, and $75 monthly rate increase. Two additional survey questions were asked about affordability and improving water quality. Forty percent of respondents said that they were “willing to pay a higher bill to improve the quality of water in creeks, streams and rivers”; while 30% said that they would not. No matter their leanings, most respondents (70%) agreed “MSD should keep sewer rates as affordable as possible for most families and businesses.” Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-13 February 2011 Figure 9-3 Rate Increase Affordability – Pre-Survey Post-Survey While roughly the same percentage of total respondents asserted that a rate increase of $35 would be “very difficult or difficult” to afford (75% versus 76%), more people (43.2% compared to 39.3%) expressed that the rate increase would be very difficult to afford. Even with their concerns about escalating rates, a similar percentage (41.8%) stated they “would be willing to pay a higher bill to improve the quality of water in creeks, streams and rivers.” Thirty percent of respondents did not, however, share these sentiments. Not surprisingly, more people (76% compared to 70%) agreed “MSD should keep sewer rates as affordable as possible for most families and businesses.” Figure 9-4 provides a summary of rate affordability findings for the post survey. Figure 9-4 Rate Increase Affordability – Post-Survey Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-14 February 2011 Confidence in MSD Pre-Survey & Post-Survey Regarding the public’s confidence in MSD’s abilities and efficacy, 52.7% of pre-survey respondents stated that they were confident in MSD’s ability to address flooding; and 53.4% were confident in MSD’s ability to reduce overflows. The post-survey findings revealed that a markedly higher percentage of people had confidence in MSD’s ability to address flooding (60%) and sewer overflows (60.3%). Program Awareness Pre-Survey Given the scope of MSD’s control plan outreach, a survey question was added that asked if respondents knew about the Clean Rivers Program. Although the survey was administered at least two weeks before communications strategies for the open houses were implemented, three out of ten (31.1%) respondents stated that they were aware of the program. The pre-survey question read: “Have you heard about MSD’s Clean Rivers Healthy Communities Program that aims to improve water quality by reducing combined sewer overflows?” While 3 out of 10 people answered yes, this number may not have been a true gauge of people’s familiarity with the program. The question’s wording and the program’s name may have made Clean Rivers appear more well-known than it was at the time. For the post-open house survey, the question was refined to gauge respondents’ knowledge of Clean Rivers’ purpose. Post-Survey The post-survey asked respondents the following: “Have you heard about MSD’s Clean Rivers Program?” If the respondent answered affirmatively, then the surveyor asked a multiple choice question that described four different program purposes. Two of ten (19.3%) respondents had heard of Clean Rivers and of those who knew about the program, only 18.6% or thirty respondents correctly stated that the program aimed to reduce sewer overflows. Though Clean Rivers was successful in changing perceptions about MSD’s effectiveness and in increasing people’s willingness to undertake some stormwater and pollution controls, additional branding and marketing is needed for more ratepayers to recognize the program’s purpose. Survey Demographics Pre-Survey As previously mentioned, more than 900 community members participated in MSD’s first LTCP public opinion survey. The demographic and geographic characteristics of these individuals were as follows: • Sixty percent lived in St. Louis County, while the remainder lived in St. Louis City; • Seventy-seven percent identified themselves as Caucasian (or white) and 20% identified themselves as African American (or black); • Thirty percent had incomes less than $35,000 and 21% had incomes ranging from $35,000 to $60,000; and • Almost seven out of ten respondents (66.6%) lived within five miles of a creek, river or other waterway. The greatest majority lived close to the River des Peres (41.7%), followed by Deer Creek (16.6%). Post-Survey Approximately, seven percent (835 compared to 904) fewer people participated in the second public opinion survey; and while the demographic and geographic characteristics were virtually the same, there were some additional attributes to consider: • The composition of males to females differed slightly with seven percent more females participating in the post-survey. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-15 February 2011 Table 9-6 Survey Completion Figure 9-5 Attendance & Survey Data • About 2% more residents indicated their household income between $100,000 and $150,000. 9.5.3 Open Houses 9.5.3.1 Background & Purpose MSD hosted a series of public open houses between March and May of 2009 that served as the main feature of its public participation program. The project team held thirteen meetings, each over a three- hour period, as well as an online forum to: • Acquaint the public with the Clean Rivers Program; • Educate residents about overflows, the sewer system, and environmental conditions; and • Review different options for reducing CSOs. Through the use of comment forms, the project team also solicited participants’ feedback on the control options they thought would work best for the region at a cost they could afford. Besides their preferred options, attendees identified the values that informed their decision-making; the waterways they felt required the greatest protections; and the additional actions they wanted MSD to undertake to advance environmental stewardship. The project team sought to maximize participation in the open houses by organizing meetings across the region – five in St. Louis City, eight in St. Louis County, and one on-line. The team originally scheduled 11 meetings and a web-based session to run from the end of March to the middle of April. The scope later changed when representatives from ACORN and MSD employees requested additional open houses to raise awareness among their group members. A total of 451 community members participated in MSD’s open houses during the extended eight-week period. Two hundred and fifty attendees, roughly 55%, completed surveys identifying their waterway priorities and values, and level of control preferences. Attendance information and survey completion data are featured in Figure 9-5 and Table 9-6 respectively. (See Appendix O for open house materials and comment form findings.) Open House Description Percentage of Surveys Completed St. Louis City Walnut Park 59.26% Lindenwood Park 38.46% Carondelet Park 42.11% ACORN 69.23% MSD 62.82% St. Louis County Ballwin 54.84% Richmond Heights 56.25% Maryland Heights 66.67% Chesterfield 59.26% Jennings 46.67% Wellston 16.67% Affton 42.11% Florissant 50.00% Online 100.00% TOTALS 55.43% Open House Attendance & Survey Comple 31 32 36 27 13 27 30 19 18 38 52 78 39 11 17 18 24 16 5 16 14 8 3 16 26 49 27 11 0 10 20 30 40 50 60 70 80 90 BallwinRichmond HeightsMaryland HeightsWalnut ParkLindenwood ParkChesterfieldJenningsCarondeletWellstonAfftonFlorissantMSD StaffACORNOnlineNumber Attending Number Completed Surveys Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-16 February 2011 9.5.3.2 Outreach & Promotions Because the sewer system is a mostly invisible utility that rarely commands widespread public attention, MSD’s project team employed a host of outreach and education vehicles to drive open house attendance. The team’s activities included: • Extensive media outreach and coverage as documented in section 9.4.6; • Paid advertising that consisted of a half-page ad in the St. Louis American, broadcasts of 100 sixty- second radio spots on Foxy 95.5 and Majic 104.9, and streaming of 40 sixty-second spots on Majic 104.9’s website; • Three E-blasts to 200,000 St. Louis City and County residents that contained information on the open houses and MSD’s discount rain barrel program. Two additional E-blasts were sent through First Civilizations to 70,000 African American residents in the region; • Three emailed invitations to Clean Rivers’ distribution list of 1,000 community stakeholders. The list includes members of area stream teams, water councils, elected leaders, municipal officials, business representatives and others; • Website announcements on Clean Rivers and MSD’s homepages. Clean Rivers’ site was also the location of the online open house. Visitors could view the open house boards and an accompanying video explanation from MSD’s Executive Director. They could also complete a comment form via Zoomerang; • Five 8-ft x 4-ft, four-sided kiosks that traveled to local libraries, colleges, municipal centers, community and recreational centers, open house sites and MSD’s headquarters. The kiosks presented the information found in the Clean Rivers brochure and open house materials; • Distribution of more than 5,000 flyers and 2,500 posters to stakeholder and community groups, open house sites, local information repositories and area municipal offices; • Two mass mailings of an open house newsletter and follow-up postcard to 5,000 stakeholders, elected officials, neighborhood and community groups, and subdivision trustees in St. Louis City and County; • One targeted mailing of participation appeal letters, open house posters and flyers, and Clean Rivers’ brochures to 750 municipal mayors and council members, public works officials, state legislators, business associations, environmental organizations and community groups. Also, every city clerk in the district received the same mailing along with copies of the project video; • More than 900 live telephone calls inviting elected officials and stakeholders to attend the open houses. Mayors and councilmen representing open house communities received an initial call and a follow-up call in order to obtain their help with constituent outreach; • Two rounds of automated telephone calls to 30,000 homeowners living in open house communities and combined sewer areas; • Presentations to community groups requesting open house information, including the Walbridge Elementary School Site Based Management Council, Woodward NOW Neighborhood Association, and 6th District Public Affairs meeting; and • Dissemination of open house materials through community information outlets. Groups like the City of Florissant, City of Frontenac, Spanish Lake Community Association, Village of Winding Trails subdivision (in Chesterfield) and Fox Borough subdivision (in Ladue) posted announcements in their newsletters and on their websites, and sent email notices to their constituents. Affton Open House Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-17 February 2011 The result of MSD’s various promotional efforts was 451 people’s involvement in its public open houses, a figure previously cited. Many of these individuals spent an average of one and one-half hours at the sessions, reviewing the 42 information boards, engaging the project team, identifying their preferences and formulating their recommendations. Their feedback has been aggregated and summarized in the following section. 9.5.3.3 Synopsis of Findings / Input The open house comment form was the principal means by which the project team obtained the public’s control plan preferences and desires. It had four key sections – waterway priorities, preferred level of control, additional actions/comments and open house effectiveness / event satisfaction. Findings for each are noted below. Waterway Priorities With slightly more than 55% (250) of attendees completing the comment form, MSD collected residents’ waterway priorities. Table 9-7 provides a look at the receiving streams attendees thought should be MSD’s primary concern and presents the logic behind their selections. Residents (44%) were most in favor of having the District focus on waterways that had relatively large CSO volumes when compared to stream flows. They believed that these rivers and streams would be most negatively affected by the resulting water pollution. Many (33%) also wanted MSD to concentrate its CSO reduction efforts on waterways that were located near residential and recreational areas because of the heightened human health risks. Waterway Priorities Public n=163 MSD n=49 Acorn n=27 Online n=11 Total N=250 All waterways should be treated the same 18% 8% 33% 18% 18% Smaller, urban waterways like Gingras Creek and the River Des Peres tributaries (Deer, Black, Hampton and Claytonia Creeks) should be a higher priority than the Mississippi River because they are close to where people live and play 32% 43% 22% 27% 33% Some waterways should be made a higher priority because the amount of sewage that flows into them (CSO volume) is large compared to the waterways’ size. The negative impacts of CSOs may be greater on these waterways 45% 45% 30% 55% 44% The Mississippi River should be a higher priority than smaller, urban waterways because its water quality impacts communities downstream from St. Louis 5% 4% 15% 0% 6% Table 9-7 Open House Waterway Priorities To further support their preferences, respondents were asked which waterways were of highest and least concern to them. The waterways considered most important included the River Des Peres (Lower/Upper) and its tributaries because of their relatively large CSO volumes and their proximity to people’s homes, recreational facilities and the increased possibility of human exposure. The Mississippi River was of least concern to respondents because of its large stream flow. Tables 9-8 and 9-9 present the findings by open house type. Richmond Heights Open House Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-18 February 2011 Waterways Public n=163 MSD n=49 Acorn n=27 Online n=11 Total N=250 River Des Peres (Lower/Middle) 35% 47% 50% 40% 39% River Des Peres (Upper) 15% 19% 5% 10% 15% River Des Peres (tributaries) 21% 19% 9% 30% 20% Maline Creek 10% 4% 14% 10% 9% Gingras Creek 1% 2% 0% 0% 1% Mississippi River 18% 9% 23% 10% 16% Table 9-8 Waterways of Highest Concern or Importance Waterways Public n=163 MSD n=49 Acorn n=27 Online n=11 Total N=250 River Des Peres (Lower/Middle) 9% 0% 4% 0% 6% River Des Peres (Upper) 4% 6% 21% 0% 6% River Des Peres (tributaries) 5% 2% 4% 0% 4% Maline Creek 9% 16% 4% 0% 9% Gingras Creek 30% 22% 13% 55% 28% Mississippi River 43% 54% 54% 45% 46% Table 9-9 Waterways of Least Concern or Importance Preferred Level of Control Open house attendees had the opportunity to review and discuss in detail possible level of control (LOC) scenarios for the six receiving streams. These were the same scenarios that were presented to the SAC at its fifth meeting. Each scenario set a goal for the annual number of overflow events on all the receiving streams and then estimated the associated capital costs and projected monthly sewer rate. After reviewing the five scenarios, respondents were asked to select their most desired LOC. As shown in Table 9-10, forty percent of those who commented chose the “Knee-of-Curve” On Urban Streams + Green On Mississippi River scenario. In addition to identifying their preferred LOC, respondents ranked the stewardship values that influenced their scenario selections; results are summarized in Table 9-11. For the majority surveyed, what mattered most was “reducing the frequency of combined sewer overflows” and “making waterways safer for the people who use or live by them.” Level of Control Public n=163 MSD n=49 Acorn n=27 Online n=11 Total N=250 Complete Elimination 3% 2% 0% 0% 2% Uniform Minimum Level Of Control Everywhere 10% 2% 15% 9% 9% “Knee-of-Curve” Everywhere 20% 38% 38% 45% 27% “Knee-of-Curve” On Urban Streams + Green On Mississippi 44% 36% 31% 18% 40% Graduated Control On Urban Streams + Green On Mississippi 23% 22% 15% 27% 22% Table 9-10 Preferred Level of Control Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-19 February 2011 Goals Public n=163 MSD n=49 Acorn n=27 Online n=11 Total N=250 Order Reduce the frequency of sewer overflows 2.5 1.8 2.7 1.9 2.4 1 -Tie Make waterways safer for the people who use or live by them 2.5 1.9 3.0 2.1 2.4 1 -Tie Keep sewer rates as affordable as possible 2.8 2.4 1.9 3.5 2.7 2 Make waterways healthier for fish / wildlife 3.3 2.6 3.6 3.7 3.2 3 Include green infrastructure as a part of this project 3.6 3.3 4.0 3.5 3.6 4 Note: Values were ranked on a scale of 1 to 5 with 1 = highest importance and 5 = least importance. Table 9-11 Stewardship Values As noted from the tables above, most participants responded similarly for each question regardless of the open house type or location. One exception is that Acorn participants rated affordability as the most critical factor for selecting their preferred LOC. However, the scenario (Knee-of-Curve Everywhere) most favored by Acorn participants was not the most affordable. This incongruent finding may have resulted from a small group participant advocating that everyone in her group select “Knee-of-Curve on Urban Streams + Green on the Mississippi River.” It is possible that those in the room may have taken her advice, but only heard the term “Knee-of-Curve.” It should be noted that the difference in the number of respondents selecting “Knee-of-Curve Everywhere” rather than “Knee-of-Curve on Urban Streams + Green on the Mississippi River” was two individuals. Given the total number of attendees at the Acorn open house, this variance is not statistically significant and both scenarios should be viewed as favorable to attendees. Additional Actions / Comments The open house comment form included two open-ended questions to solicit additional information from respondents in an unstructured manner. Almost 50% of those surveyed chose to answer both questions. While the actual comments are listed in Appendix O, Tables 9-12 and 9-13 provide a snapshot of the different types of responses. Comment Type Public n=79 MSD n=20 Acorn n=14 Online n=10 TOTAL N=123 Stormwater and/or Pollution Control Measures 27.9% 45.0% 40.0% 40.0% 33.3% Public Awareness & Education 31.7% 20.0% 13.3% 20.0% 26.8% CRHC Implementation 11.39% 10.0% 20.0% 11.4% Rate Affordability 7.6% 10.0% 20.0% 8.9% Incentives for Stormwater Control 7.6% 5.0% 10.0% 6.5% Miscellaneous 13.9% 10.0% 6.7% 30.0% 13.8% Table 9-12 Additional MSD Actions to Improve Water Quality Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-20 February 2011 Comment Type Public n=76 MSD n=15 Acorn n=15 Online n=9 TOTAL N=115 Stormwater and/or Pollution Control Measures 64.5% 46.7% 53.3% 100.0% 63.5% Public Awareness & Education 22.4% 33.3% 26.7% 22.6% Partnering 5.3% 6.67% 6.7% 5.2% Municipality Stormwater Controls 3.9% 13.3% 6.7% 5.2% Political Support 2.63% 1.7% Miscellaneous 1.3% 6.7% 1.7% Table 9-13 Additional Public Actions to Improve Water Quality Open House Effectiveness and Event Satisfaction Overall, each open house received high ratings for its presenters, process and organization. Table 9-14 provides the ratings by open house. Each statement was scored on a scale of one to five, with one being “highly agree” and five being “highly disagree.” Evaluative Category Public MSD Acorn The project team was informative. 1.22 1.50 1.44 The project team was helpful. 1.27 1.48 1.44 The project team was prepared. 1.28 1.38 1.35 The open house was well planned. 1.31 1.48 1.69 The open house was worth my time. 1.39 1.40 1.60 Table 9-14 Event Satisfaction Since online open house participants did not speak directly to the project team, the evaluation statements varied slightly. However, these participants also issued high ratings for their open house experience. Evaluative Category Virtual Reviewing the open house presentation boards online was informative. 1.00 In general, this online review was worth my time. 1.18 Table 9-15 On-line Event Satisfaction Follow-up Open Houses Following MSD’s selection of a preferred alternative for controlling CSOs, eight additional public open houses were conducted during October and November 2009. These open houses reviewed information on existing sewer conditions and overflows, reviewed options for controlling CSOs, and discussed MSD’s selected control option and the next steps in the long-term planning process. An opportunity was also provided to participate in the open houses through the Clean Rivers website, for those members of the public who could not attend one of the eight sessions in person or preferred to participate virtually. A total of 128 community members participated in this second round of open houses, making a total of 579 for all the Long-Term Control Plan open houses. 9.5.4 Voicemail & Email Address Before beginning its community presentations in April 2008, MSD set up a Clean Rivers information line (314-768-2742) that stakeholders and members of the public could access to request project information and program presentations. Callers also left messages regarding their sewer overflow questions, the open house schedule and locations, and collateral materials. Some even shared their Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 9. PUBLIC PARTICIPATION Page 9-21 February 2011 thoughts on the prospect of rate increases to pay for CSO reduction. Voicemail messages were routinely monitored with follow-up phone calls from the project team when necessary. In March 2009, an email address (outreach@cleanriversstl.com) was created prior to the launch of the open houses to serve much the same purpose as the project voicemail. Citizens wrote the project team asking for information on rain barrels, rain gardens and other green practices. They also expressed their concerns about the rate increases that were being presented at the open houses. Neither the email address nor the voicemail attracted much traffic, though they were publicized in Clean Rivers’ project materials and on its website. However, dozens of people found both to be useful points of connection to the project team. They offered additional channels for disseminating project information and for obtaining important public feedback. (See Appendix P for voicemail and email logs.) 9.6 Future Public Participation Public participation has been instrumental in MSD’s identification of both ratepayers and stakeholders’ interests, concerns and preferences. The District has incorporated the community’s input into its Long- Term Control Plan and will continue to solicit constructive feedback during the plan’s implementation. It will also maintain its outreach and education efforts through new and existing communications vehicles. By sustaining its focus on education, MSD can help ensure that more groups and individuals undertake green practices and stormwater and pollution controls to improve the health of local waterways. This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-1 February 2011 10. FINANCIAL CAPABILITY ASSESSMENT 10.1 Introduction In addition to its role as an environmental steward, the Metropolitan St. Louis Sewer District (MSD) also has an important economic role in the St. Louis region. With assets whose net book value exceeds $2.2 billion and a $247 million per annum revenue stream, MSD is a significant economic actor whose rates and charges, capital projects and programs have profound impacts on the community. MSD’s rates and charges therefore reflect a balancing1 of its economic and environmental performance objectives, to prevent creating disproportionate burdens on any sector of the community, from low income ratepayers to industrial and commercial users. Over the last 20 years, this balancing has manifested itself in a substantial financial commitment to water quality as well as significant user rate increases. Approximately $2.1 billion in capital improvements have resulted in significant reductions in sewer overflow volumes, including those described in Section 3. Cumulative rate increases of 140 percent have been experienced for typical single-family residential users, and 250 percent for typical industrial users. In determining the components and baseline schedule2 for the District’s forthcoming Capital Improvement and Replacement Program (CIRP), including the CSO controls as outlined in Section 11, the District has continued to balance its environmental stewardship and financial responsibilities through a comprehensive evaluation of its financial capabilities. This evaluation employs principles highlighted in the USEPA’s guidance document3, and employs enhancements to the workbook calculations provided therein. The District’s financial capability assessment (FCA) recognizes key imperatives of its prospective program financing that effectively define what may be financed “as expeditiously as practicable.” In particular: • MSD’s LTCP schedule has been developed in consideration of the total costs of wastewater and stormwater management services to be imposed on District ratepayers. The assessment does not parse the relative rate impacts of individual components of the District’s program but rather considers total claims on ratepayer income as an appropriate measure of burden. • Limitations on the pace and magnitude of potential service rate increases and other revenue generation measures, in combination with District capital financing practices, impose project financing constraints that may supersede project delivery constraints in scheduling projects “as expeditiously as practicable.” • Given its constraints on program financing, MSD’s LTCP schedule attempts to appropriately prioritize water quality investments such that those projects yielding greatest benefit per dollar of expenditure are scheduled first while lower return investments are deferred. • Recognizing the dynamic nature of factors impacting the financial capability of the District over a multi-decade implementation period, the District’s LTCP schedule is presented as a “baseline” that is subject to adjustment if MSD experiences significant adverse changes to its financial circumstances or other financial or budgetary issues. As noted, the District’s financial capability assessment employs general principles articulated in the CSO Control Policy and EPA Guidance – perhaps most notably that program scheduling may be determined in 1 Such balancing is contemplated in the Clean Water Act and the CSO Control Policy. 2 Specific years for completion of projects per the baseline schedule to be based on the date of approval of the District’s LTCP, and may be adjusted based on changed economic conditions as discussed herein. 3 United States Environmental Protection Agency, Combined Sewer Overflows: Guidance for Financial Capability Assessment and Schedule Development (1997) – hereinafter generally referred to as “the Guidance.” Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-2 February 2011 a manner that mitigates economic burden. It also relies on claims against household incomes as the most significant metric of economic burden. The assessment also incorporates financing assumptions designed to preserve the District’s financial health – as suggested by the Guidance’s references to Financial Indicators. However, the District’s financial capability assessment modifies and extends the analyses contemplated in the Guidance. The District’s approach is responsive to two imperatives for its prospective permits and assent to a Consent Decree consistent with its financial responsibilities: • The District must know the scope and estimated costs of the environmental investments it commits to implementing, and have the flexibility to manage the financial impacts and uncertainties thereof. • The District can commit only to program implementation schedules that recognize limitations on its evolving financial capabilities and that prioritize investments within prevailing financial and logistical constraints. 10.2 Legislative and Regulatory Intent The District’s financial responsibilities are consistent with the legislative and regulatory intent of the Missouri Clean Water Law, and the Clean Water Act and subsequent CSO Control Policy. The act calls for support of: “system[s] which constitutes the most economical and cost-effective combination of devices and systems ... at the most economical cost over the estimated life of the works ... to meet the requirements of this Act” (PL 92-500, Title II, Sec. 218(a)) The District’s baseline schedule is intended to preserve its financial health and ensure that program financing may be carried out on favorable credit terms so as to ensure implementation “at the most economical cost over the estimated life of the works.” Similarly, the District’s focus on prioritization within financial capabilities is consistent with concepts of cost-effectiveness that suggest allocation of resources to those investments yielding the highest returns per dollar of expenditure. The District’s approach is also consistent with principles of the CSO Control Policy promulgated in 1994, particularly the 3rd principle which specifically contemplates scheduling in recognition of community financial capabilities. Four key principles of the Policy ensure that CSO controls are cost-effective and meet the objectives of the CWA. The key principles are: (1) providing clear levels of control that would be presumed to meet appropriate health and environmental objectives; (2) providing sufficient flexibility to municipalities, especially financially disadvantaged communities to consider the site-specific nature of CSOs and to determine the most cost- effective means of reducing pollutants and meeting CWA objectives and requirements; (3) allowing a phased approach to implementation of CSO controls considering a community’s financial capability; and (4) review and revision, as appropriate of water quality standards and their implementation procedures when developing CSO control plans to reflect the site-specific wet weather impacts of CSOs. [emphasis added]. (Federal Register / Vol. 59, No.75, April 19, 1994 / Notices p. 18689) Neither the Missouri Clean Water Law, the Clean Water Act, nor the CSO Control Policy articulate specific limitations on the phasing of implementation schedules, or define how annual costs per household, as a percent of Median Household Income, are to be considered in developing a baseline schedule that appropriately balances environmental stewardship and financial responsibilities. No legal or specific policy mandates prevail with regard to these considerations, except that compliance be “as expeditious as Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-3 February 2011 practicable.” Accordingly, the District’s approach is fully compliant with the legislative and regulatory intent of the Missouri Clean Water Law, the Clean Water Act and subsequent CSO Control Policy.4 Finally, the District advances a practical, transparent and flexible approach to financial capability assessment that incorporates principles articulated in the CSO Control Policy (and extends and enhances analyses called for in the EPA Guidance) in that it: • incorporates the imperatives for, and local constraints on, the District’s capital financing capacity by mirroring the procedures by which the District demonstrates financial feasibility to support bonded indebtedness, • directly assesses claims on household incomes based on projected service billings, • provides for adjustment of projects and/or implementation schedules based on significant adverse changes in economic conditions that impact financial capabilities over time, and • provides a framework addressing “the specific circumstances of each permittee’s environmental and financial situation” in defining program scope and schedule. 10.3 MSD’s Financial Capability Assessment 10.3.1 Introduction The District’s approach to financial capability is not only consistent with at least the principles (if not the procedures) of EPA’s guidance, but also the common sense connotation of the term “financial capability.” Individuals and business units define their financial capabilities in terms of the volume of resources that may be committed within their constraints to finance projects. Similarly, the District’s assessment of its financial capabilities is grounded in a determination of net revenues that may be generated under feasible rate and fee increase scenarios. The feasibility of these scenarios is in part a reflection of current and projected burden of wastewater and stormwater service costs, and in part a reflection of the unique socio-economic attributes of MSD’s service area. The District’s approach to financial capability assessment and program schedule development focuses on projections of future cash-flows and the associated burden on the full spectrum of District ratepayers. Specifically, the District employed its cash flow forecasting model5 to determine the capital project financing capacity under a range of wastewater and stormwater rate slope scenarios and alternative configurations of the CIRP. Procedurally the analyses are akin to that which is required to demonstrate the feasibility of debt issues in credit markets (arguably enhancing the Guidance’s static references to financial indicators). These forecasts employ well documented and publicly available information on the District’s financial position and a number of critical assumptions. The forecast model also shows how changes in these assumptions impact the forecasts. Cash-flow projections based on alternative assumptions about the pace and magnitude of potential District rate and fee increases effectively enabled the District to determine a relevant range of potential CIRP spending that could be financed within the District’s capabilities. These scenarios were developed to recognize and account for St. Louis specific environmental and financial circumstances that constrain 4 The District’s approach also overcomes several issues on which EPA’s Guidance remains silent or is inoperable. For example, the Guidance identifies “general scheduling boundaries” and notes that the schedule “should be a time period that is negotiated between the permittee, EPA and State NPDES authorities based on the specific circumstances of each permittee’s environmental and financial situation, plus the specific nature of any engineering and construction requirements” (p.51). Yet, the Guidance is silent as to how these specific circumstances may be considered or how changes in these situations over time may be addressed. In contrast, the District’s approach facilitates the definition of program schedules and their possible adjustment over time. Similarly, the Guidance does not address how site specific factors may be incorporated into program development, while the District’s project prioritization processes incorporate site-specific factors in its prioritization and scheduling criteria. 5 Most public wastewater agencies develop cash-flow analyses for purposes of establishing annual budgets, developing rate forecasts, and general utility system financial planning. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-4 February 2011 the District’s revenue generation potential. In particular, the disparity of household income levels across the District service area is pronounced. For example, St. Louis City residents’ Median Household Incomes (MHI) are considerably lower than those in St. Louis County, $33,087 vs. $55,774, respectively. For 2009, while the weighted average MHI across these entities was estimated to be $50,5786, MHI among low-income residents7, representing over 20% of the St. Louis City population, was estimated to fall under 50% of the weighted average level at $22,616. These disparities, and the constraints on the District’s ability to redistribute revenue responsibilities across user populations, occasioned the District to develop a system rate increase scenario that limited burden to St. Louis City residents to 2 percent of MHI over the financial forecast period, which is the threshold value associated with High Burden in the EPA Guidance. While the resulting claim on Median Household Income of the combined St. Louis County and St. Louis City population8 in this financial capability-defining scenario peaks at 1.33 percent, this scenario would also result in wastewater and stormwater services consuming as much as 2.6 percent of low-income ratepayers’ MHI. Though these adverse impacts will impose acute burdens, they appropriately balance the District’s environmental and financial stewardship responsibilities. Prospective wastewater and stormwater rate increases of this baseline scenario effectively define the capital project financing capacity available within the limits of the District’s financial capabilities – for all intents and purposes the available capital project budget. The District’s LTCP schedule reflects the use of this capacity to achieve water quality improvement where expenditures are prioritized based on their contribution to water quality goals, environmental justice considerations, and project delivery imperatives. 10.3.2 Local Considerations Fundamentally, the District’s capital project financing capacity is a function of the slope of rate increases deemed to be tenable within the context of MSD’s operating environment. The District’s baseline rate increase forecast represents a financial commitment to water quality that is unprecedented in the St. Louis region. From 2009 to 2020, user charge revenues are projected to increase to over 2½ times the current values, funding $3.3 billion in capital improvements. Wastewater system rate increases are projected to be at least 10 percent per annum in 6 of those years. These service rate increases represent steeply increasing claims on ratepayers’ income, yet are contemplated to deliver project financing capacity as expeditiously as possible. They also reflect a careful navigation of local legal constraints that restrict the magnitude and structure of District rate and tax increases in any given year or rate-setting period. In particular, MSD obtains rate increase approvals through a rate commission process established through a charter amendment vote in November 2000. With respect to rate adjustments, the MSD Board and Rate Commission, which represents 15 stakeholder organizations, are to adhere to five charter defined rate criteria (§7.270): (1) Is consistent with constitutional, statutory or common law as amended from time to time; (2) Enhances the District’s ability to provide adequate sewer and drainage systems and facilities, or related services; 6 Data based on U.S. Census data, American Fact Finder, American Community Survey. 2006 Median Household Income data adjusted to 2008 values by 4 % for St. Louis City and 2% for St. Louis County. These adjustment factors were based on downward adjustments of 7 year annual average inflation rates for St. Louis City and St. Louis County respectively. For 2009 and thereafter, a 3% annual MHI adjustment factor is applied uniformly. 7 Defined as residents with incomes at or below federal poverty thresholds. 8 Based on a weighted average of the projected residential bill as a percentage of MHI with weighting based on the number of District accounts in the City and County respectively. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-5 February 2011 (3) Is consistent with and not in violation of any covenant or provision relating to any outstanding bonds or indebtedness of the District; (4) Does not impair the ability of the District to comply with applicable Federal or State laws or regulations as amended from time to time; and (5) Imposes a fair and reasonable burden on all classes of ratepayers. In general, “fairness” of rates has been accomplished through adherence to cost-of-service ratemaking procedures which allocate costs to ratepayer classes based on cost causation. As a result, the extent to which revenue responsibility for District capital financing may be shifted based on ratepayer income levels (e.g., City to County residents) is constrained. In addition, District rate increases must secure approval of a diverse set of stakeholders, many of whom may reasonably assert that service bills that exceed the 2% of MHI standard reflected in the EPA Guidance, de facto, do not satisfy the “reasonable burden” criteria. Additional constraints relate to the capital financing which prospective rate increases will support. While the District, through a charter change election in November 2000, obtained the ability to issue District- wide revenue bonds, voter approval is required. In 2004, MSD received voter approval for $500 million in revenue bonds and obtained additional authorization for $275 million in 2008. CIRP financing will require still further authorizations. Further complicating the legal landscape is the Hancock Amendment to the Missouri constitution enacted in 1980 which imposes limits on state and local government spending and taxation. In particular, Section 22 of the amendment requires voter approval of any tax or levy increases9 such as might be employed to supplement District service rate increases for purposes of more progressively financing CIRP investments. The limited potential availability of tax supported financing, imposed by the legal framework within which the District operates, must be recognized in any assessment of the District’s financial capabilities. In so doing, the District’s baseline scenario contemplates financing the entirety of the prospective CIRP through wastewater and stormwater user charge adjustments. While this assumes unprecedented rate increases and voter approval of requisite revenue bond issues, the resultant capital financing plan does not rely on tenuous tax approvals. For purposes of financial capability assessment, it enables a direct representation and balancing of associated burden. These assumed rate increases directly impact calculations of net revenues available for capital financing. This direct evaluation of prospective burden under a viable plan of finance is viewed as preferable to indirect calculations and references to historical financial indicators for the MSD service area. This is, in part, because the structure for financing local government in the St. Louis region, and generally in Missouri, is more complex and fractured than other regions (or which seem assumed by the Guidance).10 In addition, direct evaluation of burden and adjustment of program schedules in response to changing conditions will 9 “Section 22 (a) Counties and other political subdivisions are hereby prohibited from levying any tax, license or fees, not authorized by law, charter or self-enforcing provisions of the constitution when this section is adopted or from increasing the current levy of an existing tax, license or fees, above that current levy authorized by law or charter when this section is adopted without the approval of the required majority of the qualified voters of that county or other political subdivision voting thereon.” (Mo. Const. Art. X, §§ 16-24) 10 Of 6 financial measures referenced in the Guidance, two rely on some aspect of property taxation: (1) property tax revenues as a percent of full market property value and (2) property tax collection rate. However, unlike the more traditional pattern for local finance in other states in the U.S, property taxes play a much smaller role in Missouri. For example, St. Louis City government operations property taxes accounted for only 14.5% of general revenue with 71.1% coming from sales, earnings, and gross receipts taxes. For county government operations, the property tax raised 34.8% with sales and gross receipts bringing in 61.8%. (Source: Financing Local Jurisdictions In The Metropolitan St. Louis Sewer District Service Area, Don Phares, Ph.D., Economic Research, St. Louis, MO. 63114, (DRAFT – July, 2007) Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-6 February 2011 enable the flexibility called for in the CSO Control Policy.11 This is particularly important in the St. Louis region where disturbing economic trends are indicative of evolving financial capabilities. For example, between 2000 and 2006, the percentage of households below U.S. Census poverty thresholds increased in St. Louis City from 24.6% to 26.8%, in St. Louis County from 6.9% to 9.4% and across the entire MSD service area, from 11.4% to 13.8%.12 Throughout 2010, unemployment in the St. Louis Metropolitan Statistical Area exceeded 9 percent, reaching 11 percent in March 2010.13 These unemployment statistics reflect the impact of the recent economic downturn on the region’s industrial and commercial sectors. In response to these trends, and more generally its concern for the economically disadvantaged, the District maintains a Low Income Assistance program for low-income, elderly, and disabled single-family home- owners who receive sewer and storm service from MSD. Income-qualified program participants receive a rate reduction equal to 50% of their current charges for wastewater and/or stormwater services. While the District anticipates increased participation in the program with prospective rate adjustments and further District outreach, the program will not mitigate the significant burden imposed by future rate increases for the vast majority of economically disadvantaged households in the District service area.14 The District’s baseline schedule and associated rate increase plans reflect its sensitivity to the disproportionate impacts of program financing on the significant low-income populations within the MSD service area. 10.3.3 MSD Financial Planning The LTCP schedule presented in Section 11 was developed based on an iterative evaluation of CIRP configurations and associated rate adjustments. In doing so, the District employed its Long-Range Financial Planning model. The basic model structure is highlighted in Table 10-1 below: Forecast Component Description Revenues Provide basis for projections of revenues at existing rates (incorporate assumptions of account growth in District) Also includes Interest Income and Other Revenue Sources Capital funding sources Provides projections of net proceeds to be available for program implementation from revenue bonds, SRF loans, grants and contributions, and prior period fund balances O&M expenses Provide sum of baseline projections of “current wastewater and stormwater costs” and incremental annual O&M associated with program implementation15 Recurring capital financing Provides projections of routine (non-CIRP), cash financed capital outlays, annual debt service and additions to Operating Reserves CIRP expenses by component Provides projections of CIRP expenses in nominal dollars applying inflation assumptions related to capital expenses Revenue increases Provides the rate increase percentages and revenues associated with required wastewater and stormwater rates Monthly residential bills Provides projections of monthly residential bills with forecasted rate increases for water and stormwater services MHI and bills as Percent of MHI Provides projections of MHI based on inflation assumptions for St. Louis City, St. Louis County, combined and low-income ratepayers, and of these forecasted bills as a percent of forecasted MHI for wastewater, stormwater, & combined. Table 10-1 Long-Range Financial Projection Model – Forecast Components 11 Flexibility which is precluded by the Guidance’s static references to historical financial indicators. 12 The Metropolitan St. Louis Sewer District Service Area: Median Household Income And Poverty Status By Sub–Areas, Donald Phares, Ph.D., Economic Research, St. Louis, MO. 63114, (April 19, 2009) 13 U.S. Bureau of Labor Statistics , Economy at a Glance, http://www.bls.gov/eag/eag.mo_stlouis_msa.htm 14 In FY 2009, approximately 2,500 customers participated in the District’s Low Income Assistance Program while, as noted, over 20% of the St. Louis City population alone have incomes below federal poverty thresholds. 15 These values are similar to that called for in the Guidance though long-term forecast enables representation of impacts of inflation and timing of incremental impacts. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-7 February 2011 Fundamentally, the resultant cash flow projections are in a format similar to that employed to demonstrate the feasibility of bonded indebtedness. Additional outputs include projections of debt service coverage and fund balances and, consistent with this application, the District has generally employed conservative assumptions to develop its forecasts. Selected key assumptions used to develop the baseline program and schedule are provided in Table 10-2. Assumptions Basis Inflation Capital Program 3.0% Conservatively set equal to that for general operations despite higher rates experienced under more robust global economic conditions General Operations 3.0% Consistent with long-term trends in inflation rates in region and nationally Median Household Income MHI Range (2009 to 2043) $53,046 - $144,915 2006 census data for low-income, city, and county residents, weighted average MHI growth rate 3.0% Reflects exhibited trend (2000s) of growth marginally below inflation trends Capital Financing Bond Interest rate 5.0% Bond Term 30 year Bond Issuance Costs 1.40% Consistent with recent MSD issues Indebtedness limitation $5.0 Billion Targeted to ensure strong credit ratings16 Minimum debt service coverage 1.7x Rate Commission approved financial policy; targeted to ensure strong ratings Timing of Approvals Long-Term Control Plan End of 2010 Approval by all parties Rate Increase Plan End of 2011 Rate Commission approval process Revenue Bonds 2012 Bond election process requirements Table 10-2 Long-Range Financial Projection Model – Selected Key Assumptions Application of the capital program inflation assumption of 3 percent per annum to the capital program schedule yields the projected capital project spending contemplated in the baseline scenario. Pursuant to the timing assumptions whereby the District’s LTCP obtains approval by the end of calendar year 2010, and related Rate Commission and revenue bond elections occur without unanticipated delays thereafter, nearly $13 billion17 of capital spending is anticipated over the long-range financial projection period of 2009 to 2043, as illustrated in Figure 10-1. The projected CIRP expenditures shown in Figure 10-1 include costs for the major categories of CSO control, SSO control, treatment plant improvements, Cityshed improvements, Asset Management/CMOM, and additional stormwater services; as well as other projects financed by dedicated improvement funds. 16 MSD’s senior parity debt is currently rated Aa1 by Moody’s, AA+ by Standard & Poor’s, and AAA by Fitch. All three rating agencies have recognized MSD’s strong financial performance and moderate current debt burden as the basis for their favorable ratings. 17 This dollar expenditure value is in nominal dollars, reflecting the application of inflation rates. While prior cost estimates reflect base year dollar cost estimates, nearly $13 billion in cash outlays are forecast for project construction over the program implementation period. User rate and program financing projections reflect projected cash flow requirements over the forecast period. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-8 February 2011 0 500 1,000 1,500 2,000 2,500 3,000 3,500 2009-2013 2014-2018 2019-2023 2024-2028 2029-2033 2034-2038 2039-2043Millions of Dollars Figure 10-1 Baseline CIRP – Projected Expenditures in Nominal Dollars Financing this unprecedented capital investment will require substantial rate increases, particularly in the period from 2013 to 2020. These rate increases build requisite revenue generation capacity for the District to aggressively address CSO and SSO issues, but at the same time will elevate claims on ratepayer income already strained by economic decline as shown in Figure 10-2 below. 0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 2010 2015 2020 2025 2030 2035 2040Residential Bill as % of MHISt. Louis County Combined (Weighted Avg) St. Louis City Low Income EPA High Burden Threshold Figure 10-2 Baseline Scenario: Projected Typical Residential Bills as Percent of MHI by Ratepayer Group Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-9 February 2011 To the extent that 2 percent of Median Household Income may be viewed as representing a “High Burden,” as indicated by the matrix evaluation of the Guidance, the projected rate increases require portions of the District ratepayer population to approach this threshold while imposing potentially problematic burdens on low-income ratepayers throughout the District’s service area. 10.3.4 Holistic Evaluation of Program Costs Though the determination of remedial measures for the District’s systems may focus on individual system components (e.g., CSOs, SSOs), the District’s assessment of financial capability and associated development of its baseline scenario reflect a holistic evaluation of program costs. Ratepayer burden is defined by the bills to be imposed to finance water quality improvements, which also must pay for the District to effectively manage operations, renew and replace system assets, upgrade treatment facilities, and secure outstanding indebtedness. Accordingly, the District has developed projections of revenue requirements that will enable it to continue to exhibit the attributes of an “effective utility”18, including prospective compliance with current and certain anticipated future regulatory requirements.19 Similarly, the District’s financial capability assessment considers the total costs to be imposed on District ratepayers, including taxes, wastewater service charges, and stormwater service charges, because the burden on ratepayers results from all such billings.20 The District has employed conservative, industry standard practices in its estimation of capital project costs. These cost estimates were updated based on 2009 cost parameters, reflect regional cost indices, and employ industry accepted cost contingencies. However, as noted above, in conducting its financial planning, the District elected to employ a capital cost inflation assumption of 3 percent. A rapid escalation in commodity and energy prices such as that experienced from 2004 to 2008 would render the 3 percent assumption insufficient and could require the District to alter its implementation schedule for financing and project completion. In general, uncertainties like future construction cost escalation, which directly impacts the amount of project work that may be completed within the District’s financial capabilities, suggest the efficacy of a portfolio management approach that facilitates project and schedule adjustments. 10.3.5 Portfolio Management The dynamic nature of the market conditions in which the District operates, evidenced by the recent spell of highly volatile construction cost pricing from 2004 to 2008, followed by severe economic downturn through 2010, reinforce the importance of the flexibility called for in the CSO Control Policy. Risks involved in program implementation, in combination with constraints on the District’s capital financing capacity, mean that an assessment of financial capability is essentially a portfolio management problem. The District must, over its program implementation period, allocate substantial but ultimately limited resources to those investments that yield the highest returns (generally defined in terms of water quality benefits) while managing prevailing risks. 18 Recommendations for a Water Utility Sector Management Strategy: A Final Report Submitted by the Effective Utility Management Steering Committee to the Collaborating Organizations, March 30, 2007, American Public Works Association, American Water Works Association, Association of Metropolitan Water Agencies, National Association of Clean Water Agencies, National Association of Water Companies, U.S. Environmental Protection Agency, Water Environment Federation 19 However, the District’s projected capital expenditures may underestimate costs from prospective requirements related to nutrient removal and do not provide for improvements to address, for example, potential Total Maximum Daily Load limitations or requirements to address constituents of emerging concern. 20 The District’s long-range projections of revenue requirements, which reflect capital financing through a combination of debt and equity, provide for full financing of the LTCP (e.g., absent alternative revenue sources). As such, the District’s long- range financial projections facilitate evaluation of prospective burden, in that projected District service rates enable direct calculation of typical residential bills impacts. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-10 February 2011 The District’s approach to financial capability assessment (which builds on and extends procedures articulated in the Guidance) involves two fundamental activities: (1) Prioritization and (2) Risk Management. As a public agency committed to stakeholder engagement, and recognizing the monitoring and enforcement requirements of effective regulation, the District’s approach is also characterized by transparency. The District’s financial plans are based on publicly available budgets, financial statements, and credit ratings. Its project prioritization criteria reflect extensive stakeholder engagement. 10.3.5.1 Project Prioritization As discussed above, the District’s long-range financial projection model was used to effectively define the District’s capital financing capacity. Staged increases in service rates to (and for some key populations beyond) levels that will impose high burdens effectively established program budgets over defined time periods. In aggregate, the District may finance approximately21 the total levels of expenditure depicted in Figure 10-1 above. Within these boundaries of financing capacity, the District’s LTCP schedule reflects the allocation of project expenditure based on established prioritization criteria. In general, classes of projects were prioritized based on environmental benefit (e.g., CSO volume reduction), impact on receiving water quality, and necessary construction sequencing, as described in Section 11.4. However, additional considerations were taken into account in defining the District’s overall capital program scope and sequencing including: • Environmental Justice – Within the District, both historic system deficiencies and mandated remediation measures will impose disproportionate impacts on economically disadvantaged communities as demonstrated in part by the projected bills relative to MHI shown in Figure 10-2. Accordingly, the District has attempted to structure its overall capital program implementation to mitigate these environmental injustices. The District’s program specifically allocates and maintains funding levels to address localized flooding and service level issues for sewer systems within the City of St. Louis (though it should be known that this level of funding will not alleviate the entire service level issue). In addition the District has allocated and maintained specific levels of Asset Management renewal funding for the existing system, which is aged and deteriorating. The older and more critical sewers requiring this added maintenance are also located in the City of St. Louis. These program allocations are critical and must be maintained. • Project Delivery Constraints – The extensive infrastructure renewal and rehabilitation contemplated by the projects comprising the District’s CIRP must be tempered by realistic assessments of the extent to which these capital projects can be cost-effectively delivered. The District faces tangible limitations on the pace by which capital projects may be procured, permitted, designed, and constructed. Moreover, it is incumbent on the District to promote competitive bidding, limit incidence of undue price escalation, and foster local economic development. Accordingly, the District has scheduled projects to enable orderly construction, promote local contractor competition and ensure cost-effective program delivery. The District anticipates that it will work collaboratively with regulators and community stakeholders to refine the prioritization and associated scheduling of program components. This collaboration will be required to continue over the program implementation period as scheduling flexibility is required to ensure that the program remains within the District’s financial capabilities while, at the same time, effects implementation as expeditiously as possible. 21 Alternative program configurations may be accommodated within these total expenditure levels and some shifting of expenditure between 5-year period increments is tenable, to the extent that such changes do not significantly impact rate revenue requirements. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-11 February 2011 10.3.5.2 Risk Management - Project and Schedule Adjustment The District’s approach to financial capability assessment also contemplates mechanisms to assess and manage risks should significant adverse changes to its financial circumstances or other financial or budgetary issues arise. Risk management, in this context22, is addressed through project and scheduling adjustments. The District will periodically update projected cash flows developed to define its baseline scenario. Updating will include, at least, (1) current information on system revenues, (2) actual expenses and experienced cost inflation, (3) updated capital financing terms, and (4) current Median Household Income statistics. The resultant updated cash-flow forecasts will redefine the funds available for program financing. In the event that the funding level is significantly less than anticipated, or project costs are significantly higher than anticipated, the District may propose adjustments to project scopes and/or timelines consistent with available funding levels and project costs. While this periodic review of program financing constraints represents a more involved and ongoing set of calculations than contemplated by the current EPA Guidance, it is no more complex than that which is required for demonstration of the financial feasibility of credit issues. As such, it is a set of reporting requirements that permittees will be required to compile in any event to implement their programs. For regulators, it will involve well established and readily understood review procedures appropriate in the context of regulation of multi-billion dollar investments. 10.3.6 CSO Control Policy Compliance / Enhancements to Current Guidance The District’s approach to financial capability assessment builds upon and enhances the EPA guidance, while addressing several limitations that have proven problematic in practice. The two-step workbook approach employed in the Guidance defines burden by reference to a Residential Indicator and Permitee Financial Capability Indicators. The District’s approach employs the elements of these indicators within a framework consistent with utility capital financing practices: • Residential Indicator Calculation – this calculation determines the claim of current and projected utility costs on Median Household Income. Rather than indirectly calculating this claim by allocating a point-in-time estimate of costs based on the residential share of flow, the District’s approach simply calculates typical residential bills given projected rate increases over the cash-flow forecast period. The resultant residential bills relative to MHI not only directly measures the “financial impact on the District’s residential users” but also enables monitoring of these impacts over the program implementation period. • Permittee Financial Capability Indicators – this calculation attempts to evaluate the District’s financial capability by reference to debt burden, socioeconomic conditions, and financial operations indicators. However, in the case of a sanitary district like MSD, the indicators related to property values and tax revenues may not be applicable. Rather than assigning scores and calculating an index of relative financial strength divorced from the District’s capital financing imperatives, the District’s approach considers these factors in defining limits on indebtedness and prospective rate adjustments that ultimately define capital project financing capacity. 10.4 Conclusions MSD has conducted an assessment of its financial capabilities consistent with the legislative and regulatory intent of the Clean Water Act and CSO Control Policy. Its baseline schedule reflects an appropriate balancing of its environmental stewardship and financial responsibilities – providing for 22 Relating to the overall composition and scheduling of program components as opposed to risk management techniques employed in relation to individual project delivery. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 10. FINANCIAL CAPABILITY ASSESSMENT Page 10-12 February 2011 cost-effective program implementation as expeditiously as practicable within its technical limitations and financial capabilities. In so doing, MSD recognizes that cost effectiveness is not only a matter of defining lowest cost solutions but also ensuring program financing on favorable terms; it recognizes that implementation as expeditiously as practicable is not only a matter of engineering, construction and other project delivery constraints but also a question of financing capacity. MSD’s financial capability assessment builds upon the procedures employed in the Guidance and delineates a transparent, tractable, and flexible approach to program scheduling responsive to the realities of dynamic market conditions. MSD’s approach to financial capability assessment is consistent with the common sense meaning of the term “financial capability.” Using readily available information, it examines capital financing capacity within bounds defined by (tenuously) acceptable rate increases that will impose significant financial burden on the District’s ratepayer populations. It contemplates a holistic view of the District’s financial capabilities recognizing that all capital project investments, whether CSOs, SSOs, or treatment plant upgrades, place financial claims on District ratepayers. Moreover, it facilitates the balancing of unique, local considerations as called for in the CSO Control Policy and the Guidance. MSD’s baseline schedule and associated program financing plan considers the income disparities between St. Louis City and St. Louis County, the prevailing economic hardships signaled by acute unemployment, and the constraints on rate and fee increases and re-structuring. Yet, at the same time, MSD’s baseline schedule aggressively pursues the water quality improvements called for by the Clean Water Act and CSO Control Policy – contemplating total expenditures approaching $13 billion (in nominal dollars) over the full program implementation period. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-1 February 2011 11. SELECTED PLAN 11.1 Introduction This section describes the CSO Long-Term Control Plan (LTCP) selected by MSD. As described in Section 8.4, MSD selected Control Scenario 3 for implementation. This scenario consists of controlling CSOs to MSD’s urban streams to the point where further expenditures yield significantly diminished returns (the “knee-of-the-curve”), coupled with an enhanced green infrastructure program in areas with CSOs that discharge directly to the Mississippi River. Source controls and collection system controls common to all areas are also part of the selected plan, as are the CSO controls that MSD has already implemented during the planning period. As described in Section 8.4, MSD considered a number of factors in selecting the proposed controls: • Public and political acceptance of the proposed solutions, • Total program cost and resulting user rates, • Costs and benefits of existing controls, • Costs versus benefits, • Cascading effect of implementing controls, • Water quality gains, • Treatment plant impacts, and • Technical feasibility. MSD included the public in its decision making process, as described in Section 8.4 and Section 9, involving a wide array of municipal, legislator, business, environmental and public stakeholders. Financial and affordability impacts of the proposed controls were also considered, as described in Section 10. 11.2 Selected Controls MSD is committed to improving water quality in the Mississippi River, Maline Creek, and the River Des Peres and its tributaries. The selected LTCP controls will provide for significant reductions in CSO volumes and pollutant loadings while still allowing MSD the financial capability to maintain its existing infrastructure and tackle significant issues in its separate sewer systems. The selected LTCP components are listed in Table 11-1. Estimated total capital and total present worth costs for the controls are also presented; these costs have been updated to June 2009 (ENR Construction Cost Index = 8580). Note that costs for long-term CSO controls that have already been implemented by MSD, or are currently being implemented, are not included in the table. The estimated total capital cost of these completed and ongoing improvements, updated to June 2009 dollars, is $634 million. Figure 11-1 depicts the locations of the principal new components. Additional details for each plan component are presented in subsequent paragraphs. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-2 February 2011 Cost Opinions ($million)1 LTCP Component Capital Cost Total Present Worth System-wide Source Control Technologies Note 2 Note 2 Collection System Technologies Note 2 Note 2 Maline Creek Bissell Point Overflow Regulation System Note 2 Note 2 Sewer Separation of Outfalls 053 and 060 Note 2 Note 2 Treatment unit to treat overflows from Outfall 051 and storage tank to store overflows from Outfall 052 31 41 Gingras Creek Separation of three storm sewers from combined sewer system and relocation of Outfall 059 6.0 6.1 Upper River Des Peres Skinker-McCausland Tunnel to express convey separate sewer system flows around the combined sewer system Note 2 Note 2 Storage tunnel to store flows from CSO outfalls to the Upper River Des Peres 183 212 River Des Peres Tributaries Sewer separation of 15 smaller CSOs Note 2 Note 2 Elimination of all CSO outfalls to tributaries, tunnel to store/convey flows to the River Des Peres channel 396 434 Lower and Middle River Des Peres Lemay Overflow Regulation System Note 2 Note 2 Skinker-McCausland Tunnel to express convey separate sewer system flows around the combined sewer system Note 2 Note 2 Full utilization of excess primary treatment capacity at Lemay Treatment Plant Note 2 Note 2 Sewer separation of 5 smaller CSOs Note 2 Note 2 Repair of inflow to interceptor sewers under River Des Peres Note 2 Note 2 Upstream CSO controls (Upper River Des Peres) Note 3 Note 3 Flow storage in 29-ft horseshoe sewers under Forest Park and in new storage tunnel, 100 MGD treatment unit near Outfall 063, removal of secondary treatment bottlenecks at WWTP 1,103 1,208 Mississippi River Bissell Point Overflow Regulation System Note 2 Note 2 Separation of two major industrial sources Note 2 Note 2 Full utilization of excess primary treatment capacity, and maximizing flow pumped to the Bissell Point Treatment Plant Note 2 Note 2 Sewer separation for Outfall 055 Note 2 Note 2 Upstream CSO controls (Maline Creek, River Des Peres) Note 3 Note 3 Enhanced green infrastructure program 100 100 Grand Total 1,819 2,001 Notes: 1. Costs updated to ENR Construction Cost Index of 8580. 2. Costs for controls already implemented or currently being implemented are not included as LTCP future costs. 3. Costs for upstream CSO controls are reflected under the appropriate upstream components. Table 11-1 Selected Long-Term Control Plan Components Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-3 February 2011 Figure 11-1 Selected Long-Term Control Plan - Major Components 11.2.1 System-wide Controls The technology screening process previously described in Section 7 identified a number of source control technologies and collection system controls that were determined to be generally applicable throughout MSD’s combined sewer system. Many, but not all, of these controls have already been implemented as components of the Nine Minimum Controls. MSD will continue to utilize these existing controls, and implement new system-wide controls, to reduce the volume and pollutant loadings from CSOs to area receiving waters. System-wide source controls include green infrastructure, illicit connection control, stormwater detention for new developments, catch basin cleaning, solids/floatables control, illegal dumping control, hazardous waste collection, good housekeeping, street sweeping, construction erosion and waste control, litter control, industrial pretreatment program, stream teams, community clean-up programs, recycling programs, pet waste management, proper yard waste disposal, and the installation and maintenance of warning signage. MSD annually prepares a report on its accomplishments in implementing many of these controls. The implementation of green infrastructure is discussed further in Section 12. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-4 February 2011 System-wide collection system controls include diversion structure maintenance, outfall maintenance, sewer system cleaning and sewer separation for new developments or redevelopments. MSD annually reports their progress on the first three listed controls. MSD is now requiring that any new development or redevelopment in areas served by combined sewers include separation of the private sewer system. 11.2.2 Controls Specific to Maline Creek CSOs The CSO controls selected for Maline Creek are estimated to control overflows to a level of 4 overflows per year in the typical year. Figure 11-2 shows the selected controls for Maline Creek. The controls include the following components: • The existing Bissell Point Overflow Regulation System will continue to be operated to control the influence of Mississippi River stage on the capture of flows at Bissell Point Outfall 051 to Maline Creek. Refer to Section 3.2.6.1 for further information on this existing CSO control. • Infiltration and inflow (I/I) controls will be implemented in the separate sewer systems upstream of the Maline Drop Shaft as part of MSD’s efforts to eliminate constructed SSOs. Reduced peak flows resulting from I/I control may allow for greater capture of wet weather flows from the combined sewer system. • Bissell Point Outfalls 053 and 060 will be eliminated by sewer separation. In fact, these two separations have been recently completed. These outfalls were separated under MSD project 2003052A in 2008. • A 1.0 million gallon storage facility will be constructed to control overflows from Bissell Point Outfall 052. It is anticipated that the facility would be constructed adjacent to the Maline Drop Shaft. Control features will include modifications to the existing drop shaft/diversion structure, flow screening facilities, an above- or below-grade storage tank, a tank dewatering pump station, and interconnecting piping. Combined sewage will be temporarily stored at the facility during a storm event until the north leg of the Bissell Point Interceptor Tunnel has capacity to convey the return flow to the Bissell Point Treatment Plant. The flow will then be pumped out of the storage facility over a period of time not exceeding 48 hours, and receive full secondary treatment at the Bissell Point Treatment Plant. • A 94 MGD treatment facility will be built to treat CSO flows from Bissell Point Outfall 051 prior to discharge to Maline Creek. It is anticipated that the facility would be sited adjacent to the existing outfall or on a neighboring parcel. Control features will include a modified diversion structure, pump station to the treatment facility, and Enhanced High Rate Clarification1 treatment unit(s) providing screening, the equivalent of primary treatment and disinfection to the design flows prior to discharge to Maline Creek. Flows from storm events that exceed the design flow rate may receive limited treatment or bypass the facility altogether. 1 The performance, cost, and space requirements for Enhanced High Rate Clarification (EHRC) facilities were compared to those of the conventional sedimentation and disinfection tanks assessed in the alternatives screening process. In general, the comparison showed higher performance, similar costs, and smaller space requirements for the EHRC facilities. Based on this comparison, MSD elected to base its Long-Term Control Plan on the use of EHRC facilities. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-5 February 2011 Figure 11-2 Maline Creek CSO Control Components 11.2.3 Controls Specific to Gingras Creek CSOs The CSO controls selected for Gingras Creek will eliminate the occurrence of CSOs. Figure 11-3 shows the selected controls for Gingras Creek. The controls include the following components: • Three large storm sewers (two 21-inch pipes and one 30-inch pipe) will be disconnected from the existing combined sewer system and connected to a new separate storm sewer consisting of approximately 2,300 feet of 21-inch to 42-inch diameter pipe. The new storm sewer will discharge to Gingras Creek. • Bissell Point Outfall 059 will be eliminated. The existing 66-inch combined sewer will be extended to the Baden combined sewer system (Gingras Creek Branch of the Baden Trunk Sewer). The new combined sewer will run parallel to Gingras Creek approximately 4,400 feet. The sewer will most likely run underneath a portion of the Lutheran North High School campus. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-6 February 2011 Figure 11-3 Gingras Creek CSO Control Components 11.2.4 Controls Specific to Upper River Des Peres CSOs The CSO controls selected for the Upper River Des Peres are estimated to control overflows to a level of 4 overflows per year in the typical year. Figure 11-4 shows the selected controls for the Upper River Des Peres. The controls include the following components: • MSD will continue to operate and maintain the Skinker-McCausland Tunnel to express route separate sanitary flows around the combined portions of the Upper River Des Peres sewer system, thereby eliminating the overflow of this separate sanitary flow from the combined sewer system during wet weather. Refer to Section 3.2.6.3 for further information on this existing CSO control. • A 30 million gallon deep storage tunnel will be constructed to store flows from the 39 outfalls to the Upper River Des Peres (Lemay Outfalls 064, 066 to 096, 099 to102, 167, 178 and 180). The tunnel is estimated to be approximately 24 feet in diameter, extending approximately 9,000 feet from near Outfall 090 to a location near Outfall 064. The existing 39 CSO outfalls will be consolidated to approximately 4 or 5 drop shaft locations along the tunnel. The tunnel alignment and drop shaft locations will be determined during final design, based on proximity to CSOs and land availability. Partial sewer separation may be implemented where appropriate to reduce the costs for consolidation piping, as determined during final design. Partial sewer separation may be particularly applicable to some of the outlying CSOs such as Lemay Outfalls 102 and 167. The drop shafts will require adequate area above and below ground for a connecting adit and deaeration chamber that connect to the vertical drop shaft and vent shaft. A tunnel dewatering pump station will pump stored flow back to the Skinker- McCausland Tunnel and Lemay Treatment Plant for secondary treatment as capacity becomes available. Final design will determine the size and location of the tunnel dewatering pump station. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-7 February 2011 Figure 11-4 Upper River Des Peres CSO Control Components 11.2.5 Controls Specific to River Des Peres Tributaries CSOs The CSO controls selected for the River Des Peres tributaries (Deer, Black, Hampton and Claytonia Creeks) are estimated to control overflows to a level of 4 overflows per year in the typical year. Figure 11-5 shows the selected controls for the River Des Peres tributaries. The controls include the following components: • The following 15 small CSO outfalls will be eliminated by sewer separation: Lemay Outfalls 107, 108, 110, 112, 114, 115, 116, 141, 157, 160, 161, 164, 165, 174 and 175. Most of these sewer separation projects resulted from the “Phased LTCP” as discussed in Section 2.7, and included separation of both public and private portions of the combined sewer system. Some of these outfalls have been separated recently as the LTCP planning was in progress; others are in various stages of design, property acquisition, or construction. Table 11-2 indicates the status of each outfall separation. • A tunnel, approximately 20 feet in diameter and 12,000 feet long, will convey all flows from the remaining CSOs to a single location on the River Des Peres main channel in the vicinity of its confluence with Deer Creek. Consequently, the CSO outfalls along the tributaries, remaining after the above-mentioned sewer separations are completed, will be eliminated. The tunnel size necessary for total flow conveyance is adequate to provide CSO flow storage to the desired level of control. The tunnel alignment will generally follow the creek alignment from the confluence of Claytonia and Hampton Creeks to the River Des Peres main channel. Approximately five or six drop shafts are anticipated to direct flow from shallow conveyance piping to the deep tunnel. The drop shaft locations will be sited where space is available and consolidation piping is minimized in the narrow creek corridor. A dewatering pump station at the tunnel’s downstream end will pump stored flow Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-8 February 2011 from the tunnel to the Lemay Treatment Plant, where it will receive full secondary treatment, as conveyance and treatment capacity becomes available. Outfall MSD Project Number Status 107 2004054 Construction began March 2009; completion anticipated in 2011 108 2003145 Construction completed in 2008 110 2000060 Construction completed in 2008 112 2006037 Construction started in 2009; second phase scheduled for construction in FY2012 114 2005103 Construction completed in 2007 115 2003096 Construction completed in 2009 116 2005109 Construction completed in 2010 141 N/A Project is under design by MSD forces 157 2003074 Construction completed in 2006 160 2003146 Project is currently in easement acquisition process 161 2007051 Project is currently in preliminary design 164 165 2006090 Construction completed in 2008 174 2005105 Construction completed in 2010 175 2002103 Construction completed in 2010 Table 11-2 CSO Separation Projects Along River Des Peres Tributaries Figure 11-5 River Des Peres Tributaries CSO Control Components Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-9 February 2011 11.2.6 Controls Specific to Lower and Middle River Des Peres CSOs The CSO controls selected for Lower and Middle River Des Peres are estimated to control overflows to a level of 4 overflows per year in the typical year. Figure 11-6 shows the selected controls for the Lower and Middle River Des Peres. The controls include the following components: • The existing Lemay Overflow Regulation System will continue to be operated to control the influence of Mississippi River stage on the capture of flows at outfalls along the Lower and Middle River Des Peres. Refer to Section 3.2.6.1 for further information on this existing CSO control. • MSD will continue to operate and maintain the Skinker-McCausland Tunnel to express route separate sanitary flows around the combined portions of the Upper River Des Peres sewer system, thereby eliminating the overflow of this separate sanitary flow from Lemay Outfall 063 during wet weather. Refer to Section 3.2.6.3 for further information on this existing CSO control. • MSD will utilize excess primary treatment capacity at the Lemay Treatment Plant to maximize treatment during wet weather. Upon completion of influent pumping and ongoing plant outfall modifications, the expanded treatment plant will have the ability to treat 340 MGD through its preliminary and primary treatment facilities. Flow rates of up to 340 MGD will be pumped and treated during wet weather events. The current capacity of the secondary treatment facilities is 167 MGD. • The following 5 small CSO outfalls will be eliminated by sewer separation: Lemay Outfalls 046, 049, 062, 168 and 177. Most of these sewer separation projects resulted from the “Phased LTCP” as discussed in Section 2.7, and included separation of both public and private portions of the combined sewer system. Construction of three of these separations was recently completed (Outfalls 046, 049 and 177 under MSD Project No. 2006115). The Outfall 062 project is in the design and easement acquisition phase. Outfall 168 has been separated by MSD forces. • MSD will correct the excessive inflow problem to the interceptor sewers beneath the Lower River Des Peres channel that has been hampering MSD’s ability to maximize the capture of wet weather flows from its combined sewer system. These excessive inflows occur during periods of backwater due to high Mississippi River stage. The problem worsens with increasing river stage, becoming very significant above stage 20. • CSO controls implemented on the Upper River Des Peres and River Des Peres tributaries will benefit the Lower and Middle River Des Peres by reducing overflow volumes and pollutant loadings. • The existing dual 29-foot wide horseshoe sewers beneath Forest Park (immediately upstream of Lemay Outfall 063) will be utilized to store up to 25 million gallons of wet weather flow. This will be accomplished by the construction of a flow control gate at Outfall 063. The exact nature and configuration of the flow control gate (e.g. inflatable dam, hinged gate, sluice gates, or other type) will be determined during final facility design. • A 100 MGD Enhanced High Rate Clarification treatment unit will be constructed adjacent to Outfall 063 to provide for the equivalent of primary treatment and disinfection of up to 100 MGD of flow from Outfall 063. Treated flow will be discharged to the Middle River Des Peres channel. • A 206 million gallon deep storage tunnel will be constructed to store flows from the 47 outfalls to the Lower and Middle River Des Peres (Lemay Outfalls 008 to 032, 036, 037, 039, 041, 042, 043, 044, 048, 050, 052, 053, 054, 057, 058, 061, 063, 163, 170, 171, 172, 173 and 181). The tunnel is estimated to be approximately 28 feet in diameter, extending approximately 47,400 feet from Outfall 063 to a location near the Lemay Treatment Plant. The existing CSO outfalls will be consolidated to approximately 14 drop shaft locations along the tunnel. The tunnel alignment and drop shaft locations will be determined during final design, based on proximity to CSOs, land availability, and construction technique limitations. Partial sewer separation may be implemented where appropriate to reduce the costs for consolidation piping, as determined during final design. Partial sewer separation may be particularly applicable to some of the outlying CSOs such as Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-10 February 2011 Outfalls 163 and 181. The drop shafts will require adequate area above and below ground for a connecting adit and deaeration chamber that connect to the vertical drop shaft and vent shaft. A tunnel dewatering pump station will pump stored flow directly to the Lemay Treatment Plant for secondary treatment as capacity becomes available. Final design will determine the size and location of the tunnel dewatering pump station. • Flow capacity bottlenecks will be removed in the secondary treatment facilities at the Lemay Treatment Plant. These bottlenecks (e.g., distribution piping, valves, and magnetic flow meters that balance the flow to the eight aeration tanks, and obsolete aeration equipment in two of the eight tanks) currently limit secondary treatment capacity to 167 MGD. It is anticipated that this capacity can be increased to 210 MGD through removal of these bottlenecks, based on several periods of past experimental operation at similar flow rates during Mississippi River flood conditions. Stress testing will be performed to determine maximum treatable wet-weather flow rates for the plant. Figure 11-6 Lower and Middle River Des Peres CSO Control Components 11.2.7 Controls Specific to Mississippi River CSOs The CSO controls described above for the receiving waters that are tributary to the Mississippi River, coupled with the significant long-term controls already implemented on the Mississippi River outfalls and the enhanced green infrastructure program proposed by MSD, will provide meaningful reductions in overall CSO volumes and pollutant loadings to the Mississippi River. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-11 February 2011 • The existing Bissell Point and Lemay Overflow Regulation Systems will continue to be operated to control the influence of Mississippi River stage on the capture of flows at the CSO outfalls to the Mississippi River. Refer to Section 3.2.6.1 for further information on these existing CSO controls. • Two significant industrial users currently have their wastewater discharges disconnected from the combined sewer system and connected directly to the Bissell Point Interceptor Tunnel, as described in Section 3.2.6.4. These sewer system modifications result in avoiding the possible overflow of these industrial wastes, were they still connected to the combined sewer system. • MSD will utilize excess primary treatment capacity at the Bissell Point Treatment Plant to maximize treatment during wet weather. The treatment plant has the ability to treat 350 MGD through its preliminary and primary treatment facilities. Flow rates of up to 350 MGD will be pumped and treated during wet weather events, except during extremely high river stage conditions, when the capacity of the effluent pump station limits total plant flow to approximately 250 MGD. The current capacity of the secondary treatment facilities is 250 MGD. • Bissell Point Outfall 055 will be eliminated by sewer separation. In fact, this separation was recently completed in 2007 under MSD project 2003052B. • In addition to the above-noted CSO long-term controls that have already been implemented, the CSO controls implemented along Maline Creek and the River Des Peres will benefit the Mississippi River by significantly reducing CSO volumes and pollutant loadings. • MSD will implement an enhanced green infrastructure program in its combined sewer areas with CSOs that are directly tributary to the Mississippi River. It is in these areas that there exist significant opportunities for implementing green infrastructure (e.g., large commercial buildings with flat roofs, large commercial parking areas, significant quantities of vacant property that could be utilized for neighborhood-scale stormwater management, significant land redevelopment opportunities where green infrastructure can be integrated into redevelopment plans). Section 12 describes further MSD’s proposed green infrastructure program. 11.2.8 Expandability The CSO Control Policy states that selected controls should be designed to allow cost effective expansion or cost effective retro-fitting if additional controls are subsequently determined to be necessary to meet water quality standards, including existing and designated uses. The selected plan allows for future expansion to achieve additional control in the following ways: • Portions of the combined sewer system can be separated to reduce CSO volumes and pollutant loadings. • Additional storage tanks can be built to expand CSO storage capacity. • Additional treatment units can be built to increase treatment capacity at local CSO treatment facilities. • Storage tunnel dewatering rates can be increased thereby increasing the performance of fixed tunnel storage volumes. High rate treatment facilities would be needed to treat the increased tunnel dewatering flow rates. • Storage tunnels can be extended to provide additional storage volume, again coupled with higher dewatering rates and high rate treatment systems. • The Lower and Middle River Des Peres storage tunnel can be extended beneath Forest Park and configured to exclude stormwater from the Upper River Des Peres system. • Emerging technologies can be used for managing CSOs. • Increased implementation of green infrastructure can be considered. • Combinations of the above methods can be utilized. The exact methods to be used to allow CSO control expansion, if required, would be selected in the future, depending on the specific future CSO control goals. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-12 February 2011 11.2.9 Justification for Excess Flow Treatment at Bissell Point and Lemay Treatment Plants The CSO Control Policy encourages municipalities to consider the use of Publicly Owned Treatment Works (POTW) treatment plant capacity for CSO control as part of the LTCP, particularly when the treatment plant has additional primary treatment capacity in excess of secondary treatment capacity. “One effective strategy to abate pollution resulting from CSOs is to maximize the delivery of flows during wet weather to the POTW treatment plant for treatment. Delivering these flows can have two significant water quality benefits: first, increased flows during wet weather to the POTW treatment plant may enable the permittee to eliminate or minimize overflows to sensitive areas; second, this would maximize the use of available POTW facilities for wet weather flows and would ensure that combined sewer flows receive at least primary treatment prior to discharge.” (1994 CSO Control Policy, Section II.C.7) MSD’s Bissell Point and Lemay treatment plants both have primary treatment capacity in excess of their secondary treatment capacity. EPA considers flows that enter the headworks of the treatment plant, but do not receive secondary treatment, to be bypasses. The CSO Control Policy, however, notes that: “EPA bypass regulations at 40 CFR Section 122.41(m) allow for a facility to bypass some or all the flow from its treatment process under specified limited circumstances. Under the regulation, the permittee must show that the bypass was unavoidable to prevent loss of life, personal injury or severe property damage, that there was no feasible alternative to the bypass and that the permittee submitted the required notices. In addition, the regulation provides that a bypass may be approved only after consideration of adverse effects.” (1994 CSO Control Policy, Section II.C.7) With regard to the “specified limited circumstances” under which primary-treated CSO-related wet weather flows might be bypassed, the CSO Control Policy states that “for the purposes of applying this regulation to CSO permittees, ‘severe property damage’ could include situations where flows above a certain level wash out the POTW’s secondary treatment system.” The Lemay plant is susceptible to such damage due to wash-out of biomass from the activated sludge treatment system at high flow rates exceeding the hydraulic loading capacity of its secondary clarifiers. The Bissell Point plant could be damaged by high flows exceeding the hydraulic and organic loading capacity of its trickling filters, washing biomass from the filter media and perhaps even causing physical damage to the filter media, and by high flows exceeding the hydraulic loading capacity of the secondary clarifiers. Hence, CSO- related bypass could be approved to prevent long-term damage to the biological treatment processes at both treatment plants. Recognizing that secondary treatment facilities have inherent limitations and further recognizing the benefits of providing at least primary treatment for CSO flows, the CSO Control Policy states that: “for approval of a CSO-related bypass, the long-term CSO control plan, at a minimum, should provide justification for the cut-off point at which the flow will be diverted from the secondary treatment portion of the treatment plant, and provide a benefit-cost analysis demonstrating that conveyance of wet weather flow to the POTW for primary treatment is more beneficial than other CSO abatement alternatives such as storage and pump back for secondary treatment, sewer separation, or satellite treatment… EPA further believes that the feasible alternatives requirement of the regulation can be met if the record shows that the secondary treatment system is properly operated and maintained, that the system has been designed to meet secondary limits for flows greater than the peak dry weather flow, plus an appropriate quantity of wet weather flow, and that it is either technically or financially infeasible to provide secondary treatment at the existing facilities for greater amounts of wet weather flow.” (1994 CSO Control Policy, Section II.C.7) Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-13 February 2011 Consequently, the use of excess primary treatment capacity at treatment plants has long been permitted as an acceptable and expedient CSO control measure throughout the nation. 11.2.9.1 Justification for Secondary Treatment Flow Diversion Rate 11.2.9.1.1 Bissell Point Treatment Plant MSD has properly operated its Bissell Point Treatment Plant as documented by the prior five years of operating records (i.e., monthly reports of operation and discharge monitoring reports) that indicate consistent compliance with the terms and conditions of the plant’s Missouri State Operating Permit. The treatment plant has not been the subject of a compliance or enforcement activity by MDNR in the prior five years. The Bissell Point Treatment Plant has a permitted capacity of 150 MGD and currently treats an average daily flow of approximately 111 MGD. The basis of design for the Bissell Point Treatment Plant provides for a peak secondary capacity of 250 MGD, a peaking factor of 2.25 times the current average daily flow and 1.67 times the permitted flow. The Bissell Point Treatment Plant has consistently treated flows up to the peak capacity of the secondary treatment system. Since 1997 the Bissell Point Treatment Plant has been permitted to utilize its excess primary treatment capacity, and has treated up to an additional 100 MGD through primary treatment (for a total plant flow of 350 MGD) during periods of wet weather. The excess wet weather flow through primary treatment is then recombined with effluent from the secondary system prior to discharge. This wet weather mode of operation was adopted in 1997 in an effort to maximize the amount of wet weather flow that receives treatment, based upon the process capabilities of the primary and secondary treatment systems. Additionally, MSD is currently designing disinfection facilities for the plant, sized for the full 350 MGD peak wet weather flow. The disinfection facilities are expected to be on line by December 31, 2013. As indicated in the basis of design for the Bissell Point Treatment Plant, it is not feasible for the secondary treatment system to reliably treat sustained flows in excess of 250 MGD. Specifically, the peak hydraulic loading rate for the trickling filters of 2.5 gpm/ft2 was selected to prevent excessive wash-off of biomass and physical damage to the filter media. The secondary clarifier loading rates at the peak flow of 250 MGD (1,200 gpd/ft2 surface overflow rate, 30 lb/day/ft2 solids loading rate, and 44,200 gpd/lf weir overflow rate) were selected based upon the specific clarifier design and the Recommended Standards for Wastewater Facilities, Great Lakes – Upper Mississippi River Board of State and Provincial Public Health and Environment Managers (Ten States Standards), and MDNR Design Guides (10 CSR 20-8). The hydraulic limitations of the trickling filters and secondary clarifiers make it technically infeasible for the treatment plant to provide secondary treatment to greater amounts of wet weather flow. The Bissell Point secondary treatment process was originally designed as a two-stage treatment process due to the high-strength waste existing at that time. The treatment process includes 6 trickling (roughing) filters followed (in series) by activated sludge treatment. The activated sludge treatment units are not currently used due to significantly reduced influent BOD loadings; they may be required to meet future nutrient control requirements. MSD has considered whether the trickling filters and the activated sludge aeration basins could be operated in parallel to allow more flow to pass through secondary treatment. There are several reasons why the trickling filters and aeration basins cannot now be operated in parallel. First, the primary settling tank weir crest elevation is 417.75 feet. The top of the trickling filter media is at an elevation of 466.50 feet. Pumps that can overcome this large static head (approximately 55 feet considering the hydraulic losses between the primary settling tanks and trickling filter pump station, and the head needed to drive the rotary distributors on top of the trickling filters) are used to pump the primary effluent flow Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-14 February 2011 to the trickling filters. The design water surface elevation in the aeration basin inlet channel is 423.70. As this elevation is higher than the primary settling tank weir crest, it is clear that primary effluent cannot flow by gravity into the aeration tanks; it would also need to be pumped, but the static head is significantly lower (less than 10 feet). The trickling filter feed pump design (high static head) is simply not suitable for lifting flow to the aeration tanks. Even if the existing pumps could operate under the required conditions, and had the required additional flow capacity, no piping is presently configured to convey the flow to the aeration tanks. A new or additional pump station and associated piping would be needed to simultaneously feed the trickling filters and aeration basins. Additional piping or channels would be needed to simultaneously convey flow from both treatment systems to the secondary clarifiers. Second, the firm capacity of the existing secondary clarifiers is 250 MGD. Passing 350 MGD through these clarifiers during wet weather would significantly degrade effluent quality and risk violation of the plant’s operating permit. It is also infeasible that flow rates to the clarifiers could be increased by the required 40 percent due to resulting excessive hydraulic head losses through existing piping, fittings and piping equipment. Rather, the addition of four new secondary clarifiers would be required to accommodate higher flow rates. Third, and perhaps most importantly, there is insufficient primary effluent BOD loading to sustain 6 trickling filters and 3 parallel aeration tanks (assuming a 350 MGD design wet weather flow rate) in viable operation. The existing secondary treatment systems were designed for a total daily plant influent BOD loading of 472,000 lbs/day. Due to reductions in population and industrial loads, the plant’s current (FY 2009 average) loading is only 88,000 lbs/day. As noted above, use of the aeration tanks has consequently been discontinued. The existing aeration equipment (blowers and diffusers) is also significantly oversized for the current organic loading. While the aeration equipment could be modified at a price, the problem of sustaining a larger biological treatment systems with insufficient food (BOD loading) remains. Based upon the above discussion, the Bissell Point Treatment Plant is properly operated and maintained. The existing facilities can be operated such that wet-weather flows of 250 MGD are treated through secondary treatment – the capacity of those facilities, while 350 MGD of wet-weather flow can be treated through the preliminary and primary treatment facilities. Facilities for disinfecting all wet- weather flows are currently being designed and are expected to be on line by December 31, 2013. Expansion of the existing secondary treatment facilities beyond 250 MGD is not technically feasible. 11.2.9.1.2 Lemay Treatment Plant MSD has properly operated its Lemay Treatment Plant as documented by the prior five years of operating records (i.e., monthly reports of operation and discharge monitoring reports) that indicate consistent compliance with the terms and conditions of its Missouri State Operating Permit. The treatment plant has not been the subject of a compliance or enforcement activity by MDNR in the prior five years. The Lemay Treatment Plant has a permitted capacity of 167 MGD and currently treats an average daily flow of 114 MGD. The treatment plant has consistently treated flows up to the 167 MGD capacity of the secondary treatment system. The LTCP includes a project to alleviate restrictions in the secondary system, thereby allowing an estimated additional flow rate of 43 MGD to be treated through the secondary system, providing an anticipated peak secondary capacity of 210 MGD. This will provide a peak secondary treatment capacity of 1.26 times permitted capacity and 1.84 times average daily flow. The primary clarifiers at the Lemay Treatment Plant have a peak capacity of 340 MGD. MSD has requested that the Lemay Treatment Plant be allowed to provide primary treatment to plant flows exceeding the capacity of the secondary system during periods of wet weather. The excess wet weather flow receiving primary Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-15 February 2011 treatment would then be recombined with effluent from the secondary system prior to discharge. Additionally, MSD is currently designing disinfection facilities at the Lemay Treatment Plant sized for 340 MGD. The disinfection facilities are expected to be on line by December 31, 2013. As indicated in the basis of design for the Lemay Treatment Plant, it is not feasible for the secondary treatment system to reliably treat sustained flows in excess of their design capacity. Specifically, the secondary clarifier loading rates at peak flow (1,100 gpd/ft2 surface overflow rate and 21,000 gpd/lf weir overflow rate) were selected based upon the specific clarifier design, Recommended Standards for Wastewater Facilities, Great Lakes – Upper Mississippi River Board of State and Provincial Public Health and Environment Managers, and MDNR Design Guides. The hydraulic limitations of the secondary clarifiers make it technically infeasible for the treatment plant to provide secondary treatment to greater amounts of wet weather flow without risking damage, i.e., washout of biomass. Operational issues also arise at high flow rates, including a reduced ability to properly balance influent flows and return sludge flows to the aeration tanks. As noted above, MSD is planning a project to increase the wet-weather flow capacity of the existing secondary treatment facilities. Six of the existing eight aeration tanks are presently equipped with fine bubble aeration diffusers. These six tanks are operated in a step feed mode (return activated sludge to the first pass, primary effluent distributed among the final three passes). The other two aeration basins still have their original coarse bubble diffusers, as well as condition issues, which prevent their use at present. These two tanks have, on occasion, received flow when the aeration tank influent channel has overtopped its walls. This occurs when the plant has had to pass flow rates of 240 MGD (e.g., during extreme flood conditions). Any flow thus entering the tanks was stored and returned to the treatment process when capacity became available. The LTCP includes a project to allow these tanks to be brought on line, thereby increasing secondary treatment capacity at the Lemay plant. This will require new and modified aeration equipment, tank repairs, and other improvements to remove hydraulic bottlenecks, along with associated modifications to process controls and other support facilities. MSD has considered whether process modifications could be made to allow greater flows to be handled without washing biomass from the system. The plant, however, is already using a step feed system to help retain biomass due to weak-strength influent flows. No additional process modifications have been identified that would allow for higher flow rates to be treated. MSD has also considered whether additional secondary treatment capacity could be added to the plant, and concluded that the addition of aeration tank and final clarifier capacity is not feasible as the average organic loading (food) to the treatment plant is not sufficient to reliably maintain the additional mixed liquor (microorganism mass) that would result from an expansion of the secondary treatment facilities. Based upon the above discussion, the Lemay Treatment Plant is properly operated and maintained. The existing facilities can be operated such that wet-weather flows of 167 MGD are treated through secondary treatment – the capacity of those facilities – while up to 340 MGD of wet-weather flow can be treated through the preliminary and primary treatment facilities, following completion of influent pumping and ongoing plant outfall modifications. Modifications of the secondary treatment facility, and subsequent stress testing, are planned as part of the LTCP to increase the wet-weather flows through the aeration tanks and final clarifiers to an estimated capacity of 210 MGD. Facilities for disinfecting all wet-weather flows are currently being designed and are expected to be on line by December 31, 2013. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-16 February 2011 11.2.9.2 Feasible Alternatives Benefit-Cost Analysis The following paragraphs present a benefit-cost analysis demonstrating that conveyance of wet weather flow to the POTW for primary treatment is more beneficial than other feasible CSO abatement alternatives such as storage and pump back for secondary treatment, sewer separation, or satellite treatment. 11.2.9.2.1 Bissell Point Treatment Plant Benefits. At the Bissell Point Treatment Plant, the discharge of excess primary-treated CSO-related flows, blended with secondary effluent, is to the Mississippi River. As discussed in Section 3, MSD reviewed water quality data collected for the CSO program with numeric criteria in MDNR’s water quality standards. The only potential pollutant of concern identified for the Mississippi River relative to MSD’s CSO discharges is E. coli (indicator bacteria). All wastewater passing through the Bissell Point Treatment Plant, whether it is primary-treated and blended, or receives full secondary treatment, will be disinfected to meet Missouri’s effluent regulations for E. coli. It is assumed that any alternative to the proposed conveyance of flow to the POTW for primary treatment and blending (e.g., additional storage and pump back for secondary treatment) would also provide disinfection to meet the effluent regulations. Hence, any alternative CSO control measure would result in an identical bacteria density in the treated effluent, and no change in bacteria loading to the Mississippi River. Given the identical benefits relative to indicator bacteria for all alternatives, the issue of the most beneficial alternative from a cost-benefit standpoint becomes one of determining the least expensive alternative for managing the excess CSO-related flow. Costs. The existing Bissell Point Treatment Plant currently has the ability to treat excess wet weather flows by utilizing its additional primary treatment capacity in excess of secondary treatment capacity. Since 1997, the plant has been permitted to utilize its excess primary treatment capacity, and has been treating up to an additional 100 MGD of wet weather flow through its primary treatment facilities, and combining (blending) this excess primary effluent with secondary effluent prior to discharge. Because the treatment facilities already exist, there is no additional capital cost associated with employing this CSO control scheme. In contrast, any alternative to the current flow blending scheme, such as flow storage, sewer separation, or satellite treatment, would entail additional capital costs. Given the additional cost of any alternative to the current flow blending scheme, and the lack of additional water quality benefits relative to indicator bacteria that would be derived from any alternative, MSD’s selected alternative for the LTCP is to continue to utilize the excess primary treatment capacity at the Bissell Point Treatment Plant. Conclusions. In accordance with the CSO Control Policy, MSD has demonstrated that it has excess primary treatment capacity at its Bissell Point Treatment Plant. MSD can utilize this capacity to maximize the use of available POTW facilities for wet weather flows, while providing at least primary treatment and disinfection to these CSO-related flows prior to discharge. MSD has demonstrated that bypassing these primary-treated flows around the secondary treatment facilities is unavoidable to prevent severe property damage, and that expansion of the secondary treatment facilities is not feasible. MSD has provided justification for the cut-off point at which the flow will be diverted from the secondary treatment portion of the treatment plant. MSD has provided a benefit-cost analysis demonstrating that conveyance of wet weather flow to the plant for primary treatment is more beneficial than other CSO abatement alternatives such as storage and pump back for secondary treatment, sewer separation, or satellite treatment. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-17 February 2011 11.2.9.2.2 Lemay Treatment Plant Benefits. At the Lemay Treatment Plant, the discharge of excess primary-treated CSO-related flows, blended with secondary effluent, is to the Mississippi River. As discussed in Section 3, MSD reviewed water quality data collected for the CSO program with numeric criteria in MDNR’s water quality standards. The only potential pollutant of concern identified for the Mississippi River relative to MSD’s CSO discharges is E. coli (indicator bacteria). All wastewater passing through the Lemay Treatment Plant, whether it is primary-treated and blended, or receives full secondary treatment, will be disinfected to meet Missouri’s effluent regulations for E. coli. It is assumed that any alternative to the proposed conveyance of flow to the POTW for primary treatment and blending (e.g., additional storage and pump back for secondary treatment) would also provide disinfection to meet the effluent regulations. Hence, any alternative CSO control measure would result in an identical bacteria density in the treated effluent, and no change in bacteria loading to the Mississippi River. Given the identical benefits relative to indicator bacteria for all alternatives, the issue of the most beneficial alternative from a cost-benefit standpoint becomes one of determining the least expensive alternative for managing the excess CSO-related flow. It should also be noted that the proposed use of the excess treatment capacity at the Lemay Treatment Plant will provide for primary treatment and disinfection of substantial volumes of wet weather CSO- related flow during the time period while the LTCP’s other CSO control measures are being constructed and started up. These volumes are estimated to be as high as 800 million gallons in the typical year, following completion of influent pumping and ongoing plant outfall modifications. Costs. MSD considered a number of alternatives for managing CSO flows in its Lemay combined sewer system, including sewer separation, satellite or local treatment, local storage, tunnel storage, and source reduction through green infrastructure. MSD’s selected plan includes sewer separation, inline storage, tunnel storage, and utilization of excess primary treatment capacity at the Lemay Treatment Plant. The use of excess primary treatment capacity was determined to be necessary in order to achieve the level of control identified in the selected plan. A range of bypass/blended flow rates was evaluated to determine an optimal balance between CSO loadings to receiving waters and the quantities of primary-only and primary-secondary treated CSO. MSD has examined a number of alternatives to the planned utilization of excess primary treatment capacity. These alternatives are listed below and summarized in Table 11-3 together with estimated capital costs and a comparison with the least-cost alternative. Alternative 1: Utilization of Excess Primary Treatment Capacity at the Lemay Treatment Plant. This alternative includes making modifications to the existing secondary treatment facilities to increase their wet weather capacity to 210 MGD, and treating peak wet weather flows of up to 340 MGD through the primary treatment facilities. Excess primary-treated flows are blended with secondary-treated flows. All flow is disinfected prior to discharge to the Mississippi River. This alternative is part of the selected plan described in the LTCP. Alternative 2: Add Storage. This alternative consists of adding sufficient storage to the proposed Lower and Middle River Des Peres Storage Tunnel to reduce or eliminate the use of excess primary treatment capacity at the Lemay Treatment Plant followed by blending and discharge to the Mississippi River. Alternative 2a: To completely eliminate flow blending at the treatment plant requires an estimated storage volume of 119 million gallons in addition to the proposed 206 million gallon storage tunnel. Because there is insufficient land available to site a local storage Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-18 February 2011 tank of this volume, the only option is to increase the tunnel volume. As the total required volume – 325 million gallons – is too large for a single tunnel, a second parallel tunnel is required. And due to the limitations on secondary treatment capacity at the Lemay Treatment Plant, it is not possible to dewater these parallel tunnels fast enough to maintain tunnel system performance at 4 overflows in the typical year. Consequently, this alternative includes a 100 MGD high-rate treatment facility to treat excess flow resulting from the dewatering of the tunnel, so as to maintain performance at the desired level of 4 overflows in the typical year. Alternative 2b: To reduce the volume of flow blending at the Lemay Treatment Plant by 50 percent requires an estimated storage volume of 20 million gallons in addition to the proposed 206 million gallon storage tunnel. Similar to Alternative 2a, there is insufficient land available to site a local storage tank. Consequently, this alternative includes the addition of an estimated volume of 20 million gallons to the proposed 206 million gallon tunnel and a larger tunnel dewatering pump station. Alternative 3: Satellite Treatment. This alternative includes a 130 MGD high-rate treatment and disinfection facility located near the downstream end of the storage tunnel to replace the 130 MGD excess flow treatment provided at the Lemay Treatment Plant under the LTCP’s selected scenario. Alternative 4: Enhanced Treatment. This alternative consists of enhancing the performance of the primary clarifiers at the Lemay Treatment Plant with chemical feed (chemically-enhanced primary treatment). This alternative was deleted from further consideration as it would technically still involve the bypassing of flows at the Lemay Treatment Plant. Alternative 5: Sewer Separation. This alternative includes separating a substantial area of the combined sewer system such that peak flow rates in a three-month storm would be reduced by approximately 130 MGD. This alternative was dismissed from further consideration as it would actually increase bacteria and pollutant loadings to the River Des Peres (increased stormwater discharges directly to the river) in exchange for less blending at the Lemay Treatment Plant. Alternative 6: Expand Lemay WWTP. This alternative consists of expanding the secondary treatment facilities at the Lemay Treatment Plant to 340 MGD to match the capacity of the primary treatment facilities. This alternative has been dismissed from further consideration for the reason explained above – there is insufficient organic loading to the plant to sustain a secondary treatment process of this size during dry weather flow. Alternative Description Estimated Capital Cost ($million) % Above Lowest Cost Alternative 1. Flow Blending Modification to allow 210 MGD flow $20 0% 2a. Add Storage to Eliminate Flow Blending Add 120 million gallons volume to proposed 206 million gallon tunnel $623 3015% 2b. Add Storage to Reduce Flow Blending 50% Add 20 million gallons volume to proposed 206 million gallon tunnel $50 150% 3. Satellite Treatment 130 MGD high rate treatment $60 200% 4. Enhanced Treatment Chemically-enhanced primary treatment Not feasible -- 5. Sewer Separation Separate part of combined sewer system Not feasible -- 6. Expand Lemay WWTP Expand secondary treatment to 340 MGD Not feasible -- Table 11-3 Flow Blending Alternatives – Lemay Treatment Plant Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-19 February 2011 Given the high cost of the alternatives to flow blending at the Lemay Treatment Plant and the lack of additional water quality benefits relative to indicator bacteria that would be derived from any of the alternatives, MSD’s selected alternative for the LTCP is to utilize the excess primary treatment capacity at the Lemay Treatment Plant and increase the capacity of the secondary treatment facilities to 210 MGD. Stress testing will be conducted to confirm the treatment plant’s capacities. Conclusions. In accordance with the CSO Control Policy, MSD has demonstrated that it has excess primary treatment capacity at its Lemay Treatment Plant. MSD can utilize this capacity to maximize the use of available POTW facilities for wet weather flows, while providing at least primary treatment and disinfection to these CSO-related flows prior to discharge. MSD has demonstrated that bypassing these primary-treated flows around the secondary treatment facilities is unavoidable to prevent severe property damage, and that expansion of the secondary treatment facilities is not feasible beyond the treatment capacities anticipated after implementation of the LTCP. MSD has provided justification for the cut-off point at which the flow will be diverted from the secondary treatment portion of the treatment plant. Stress testing at the Lemay plant will determine whether this cut-off point can be raised. MSD has provided a benefit-cost analysis demonstrating that conveyance of wet weather flow to the plant for primary treatment is more beneficial than other CSO abatement alternatives such as storage and pump back for secondary treatment, sewer separation, or satellite treatment. 11.3 Water Quality Benefits of Selected Controls MSD evaluated current impacts of CSOs and the expected benefits of implementing CSO controls in Sections 3, 5, and 6. This section provides an analysis of the reduction in CSO and associated water quality benefits with the selected controls. This analysis includes a calculation of the expected reductions in pollutants of concern (E. coli bacteria, five-day biochemical oxygen demand, and ammonia nitrogen) in Maline Creek and the River Des Peres, and whether the controls will result in attainment of recreational and aquatic life uses. As discussed below, MSD has demonstrated that the CSOs that will remain after implementation of the LTCP will not impair these uses. The analysis also indicates that a site-specific dissolved oxygen criterion for the River Des Peres and Maline Creek will be necessary. This is because it is not possible to meet the 5 mg/L minimum criterion in these waterways, even if other sources of non-attainment were addressed, because of a number of factors unrelated to CSO. 11.3.1 Pollutant Load Reductions with the Selected Controls As discussed above, MSD’s selected controls will result in four overflows per typical year to Maline Creek and the River Des Peres and its tributaries. CSOs to Gingras Creek will be eliminated. CSOs to Gravois Creek have already been eliminated. The resultant reductions in CSOs to these urban streams will benefit the Mississippi River as well. Enhanced green infrastructure will be used to further reduce direct CSO discharges to the Mississippi River. Table 11-4 provides a summary of the modeled pollutant loads to these waterways in a typical year and the expected reductions with implementation of the LTCP. The loadings include synergistic effects of all CSO control measures in combination, when fully implemented. The expected reduction in direct CSO discharge to the Mississippi River due to the enhanced green infrastructure program (which is not shown) will be determined after additional data are collected, as described in Section 12. The reductions in CSO volume and pollutant loadings listed in Table 11-4 are in addition to the substantial reductions already achieved by MSD, as discussed previously in Sections 1.3 and 3.2.6. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-20 February 2011 Lower & Middle RDP Maline Creek Upper RDP Parameter Units Pollutant Loads Percent Reduction Pollutant Loads Percent Reduction Pollutant Loads Percent Reduction Volume MG 1,177 / 664* 70 21 / 125* 86 78 85 CBOD5 tons 258 58 14.4 28 9.7 85 Ammonia N tons 10.86 67 0.85 10 0.45 85 Organic N tons 36.6 70 1.45 28 1.68 85 E. coli million counts 1.83 x 1010 67 1.64 x 108 90 9.54 x 108 82 * Volumes represent untreated / treated CSO remaining after implementation of the LTCP Table 11-4 Modeled Pollutant Loads Resulting from the Selected Controls in a Typical Year 11.3.2 Summary of Water Quality Impacts of CSOs A primary objective of the CSO Control Policy is to meet water quality standards through cost-effective CSO control. CSOs have the potential to cause exceedances of water quality criteria that are intended to protect beneficial designated uses, in particular recreational and aquatic life uses. Missouri has procedures for assessing whether these exceedances cause an impairment of these uses (MDNR, 2009). For example, if the geometric mean of E. coli bacteria measurements during the recreation season is equal to or less than 1,134 colony-forming units per 100 milliliters (cfu/100ml) for the last three years, then the waterway is fully supporting the secondary contact recreation use. For aquatic life uses, Missouri’s procedures specify if at least 90 percent of the dissolved oxygen samples collected during a year are 5 mg/L or more, then the waterway is fully supporting protection of aquatic life (based on dissolved oxygen conditions). Water quality data collected by MSD and the USGS (discussed in Section 3), along with collection system and water quality models developed by MSD (discussed in Sections 4, 5 and 6), showed that: • Ammonia criteria, acute and chronic, are met under existing conditions for all receiving waters. • The geometric mean bacteria criterion for secondary contact recreation is met under existing conditions for all receiving waters. • The dissolved oxygen criterion is met in the Mississippi River under existing conditions. • The dissolved oxygen criterion is not met more than 70 percent of the time in Maline Creek. Eliminating CSOs, however, would not improve this condition (particularly in the upper reaches that do not receive CSO discharges). • The dissolved oxygen criterion is not met in the Lower River Des Peres and the Upper River Des Peres, and a small (10 to 15) percent of this is related to existing CSO discharges. EPA’s CSO Control Policy offers two approaches (“Presumption” and “Demonstration”) for development and implementation of an LTCP. MSD has selected the “Demonstration” approach based on the findings described above. Data showed that the Mississippi River is meeting the secondary contact recreation and dissolved oxygen criteria under existing conditions. Water quality models demonstrated that the secondary contact recreation criterion is met in Maline Creek and the River Des Peres under existing conditions. Data and models showed that the dissolved oxygen criterion (or even a minimum of 4 mg/L which is the recommended federal criterion) is not being met under existing conditions in these waterways, and would not be met even if CSOs were eliminated. The models were therefore used to evaluate the contributing factors to these impairments. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-21 February 2011 11.3.3 Contributing Factors to Dissolved Oxygen Impairments Despite the significant reductions shown in Table 11-4, the selected controls (Scenario 3) are expected to only slightly improve the percent compliance with the dissolved oxygen criterion in the River Des Peres and Maline Creek. Section 6.3 discussed how elimination of CSO does not affect the percent of time that the dissolved oxygen criterion cannot be met in Maline Creek, because of the small volume of CSO relative to upstream and stormwater sources. For the River Des Peres, elimination of CSO was forecasted to somewhat improve compliance with the dissolved oxygen criterion. This section therefore examines the benefits associated with the selected CSO controls for the River Des Peres relative to addressing other factors, such as sediment oxygen demand (SOD). As shown in Figure 11-7, the selected controls result in the same level of compliance with the minimum dissolved oxygen criterion as elimination of CSO for the Upper River Des Peres. For the Middle and Lower River Des Peres (Figure 11-8), some of the segments of the waterways showed that the percent compliance was the same with the selected controls as if the CSOs were eliminated. For other segments, there were differences in compliance between the selected CSO controls and CSO elimination. Figure 11-7 Typical Year Minimum DO Compliance for Upper River Des Peres Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-22 February 2011 Figure 11-8 Typical Year Minimum DO Compliance for Lower River Des Peres As discussed in Section 5, there are a number of factors that prevent this attainment of the designated use (warm water aquatic life). These factors include diurnal swings in dissolved oxygen from plant photosynthesis and respiration (PR), wet weather discharges (including remaining CSOs and storm water), SOD, high temperatures, and reductions in flow and reaeration due to backwater conditions created by the Mississippi River. Sensitivities conducted with the models show that factors other than SOD are more significant in controlling dissolved oxygen levels. For example, diurnal swings in dissolved oxygen caused by plant growth are sufficient to violate the state’s criterion. Also, modeling of the lower portions of the River Des Peres and Maline Creek shows that velocities are nearly zero during backwater conditions. This means that wet weather loads (including storm water) delivered to these lower reaches will continue to exert oxygen demand for extended periods. This oxygen demand will be exacerbated by reduced reaeration because of quiescent conditions, and also by reduced dispersive mixing with the Mississippi River due to backwater. Model simulations were conducted with the selected CSO controls to test the impacts of the remaining CSOs on dissolved oxygen, assuming that other factors were addressed. Three phases of successively increased control were simulated. In the first simulation, dissolved oxygen concentrations at the upstream boundaries were set to 85% of saturation, and storm water loads were eliminated. In the second, PR effects were reduced such that diurnal swings were generally between 1 and 2 mg/L. In the third simulation, SOD levels were reduced to between 0.5 and 1 grams per square meter per day (gm/m2/d). The results of these simulations are shown in Figures 11-9 (Upper River Des Peres) and 11-10 (Middle and Lower River Des Peres). In general, storm water load reductions show small to moderate gains in percent time of compliance, but a more dramatic increase in seen when PR effects are controlled. Reductions in SOD produce small marginal gains, especially for the Upper River Des Peres. It is noted that loads, PR and SOD are related in ways that were not modeled explicitly; for example, algal growth depends on nutrient load. However, other factors contribute to excessive algal growth, including lack of riparian shading and a riverbed composed of coarse substrate that facilitates growth of attached algae. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-23 February 2011 Stream restoration activities, which could also reduce instream temperatures (and increase dissolved oxygen), should therefore play a role in any watershed-based approach to achieving attainment of water quality standards. Figure 11-9 Typical Year Minimum DO Compliance for Upper River Des Peres with Various Additional Controls Figure 11-10 Typical Year Minimum DO Compliance for Lower River Des Peres with Various Additional Controls Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-24 February 2011 11.3.4 Review and Revision of Water Quality Standards Because of the issues discussed above, even eliminating the CSOs and storm water loads will not meet the dissolved oxygen criterion in Maline Creek and the River Des Peres. The CSO Control Policy encourages permitting and water quality standards (WQS) authorities to consider a number of options for establishing the highest attainable designated use that can be achieved with an appropriate level of CSO control. Specifically the policy states: “In reviewing the attainability of their WQS and the applicability of their implementation procedures to CSO-impacted waters, States are encouraged to define more explicitly their recreational and aquatic life uses and then, if appropriate, modify the criteria accordingly to protect the designated uses.” EPA has developed guidance to assist States and CSO permittees with developing appropriate aquatic life uses for waterways impacted by wet weather discharges (EPA, 2001). This guidance can also be used to evaluate all of the potential factors specified in the Clean Water Act for revising designated uses at 40 CFR 131.10(g). In the guidance, EPA states “when the aquatic life in a water body is more explicitly defined, states and the public are better able to evaluate the potential of the water body to support healthier aquatic communities.” EPA further states “implementation of a well-designed and operated LTCP may not necessarily ensure the attainment of water quality standards within the CSO receiving water. Where existing standards cannot be met, CSO communities, states, and EPA will need a more intensive process… to reach early agreement on the data and analyses that will be sufficient to support both the development and implementation of the LTCP and the water quality standards review.” Modeling demonstrated that factors other than CSO (and even SOD potentially associated with CSO) are causing the impairment of the aquatic life use in Maline Creek and the River Des Peres. Modeling also demonstrated that Missouri’s minimum dissolved oxygen criterion of 5 mg/L could not be met even if these other factors were addressed. This suggests that a Use Attainability Analysis (UAA) is required for Maline Creek and the Middle and Lower River Des Peres (and perhaps portions of the Upper River Des Peres) to determine the highest attainable use. Preparation of the UAA should not delay agreement on the selected CSO controls because it is clear that even elimination of the CSO would not address the stream impairments. 11.4 Implementation Schedule Implementation of the CSO controls comprising the Long-Term Control Plan (LTCP) will require a time period of 23 years after the LTCP is approved. This period includes time to design the projects associated with the controls, secure necessary rights-of-way, coordinate with other service area improvement projects, coordinate manpower and material resource demands, construct the projects, evaluate their effectiveness, and manage the financial burden on ratepayers. As discussed in Section 8.4.6, the Stakeholder Advisory Committee and the general public strongly believed that CSO control efforts should be focused on those waterways that are most impacted by CSO discharges and are close to where people live and play. Further, any controls on the River Des Peres, River Des Peres tributaries, Gingras Creek, and Maline Creek will also benefit the Mississippi River. Figure 11-11 shows the LTCP Program Implementation Schedule, which was developed with these priorities in mind. Controls that have already been implemented are not included in the schedule. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-25 February 2011 Figure 11-11 LTCP Program Implementation Schedule As discussed in Section 11.5, MSD intends to submit annual reports as the CSO controls and associated projects are implemented. As part of these reports, the implementation schedule will be reviewed and adjusted if needed to allow MSD to incorporate new data and adapt the plan to fit changing circumstances (such as economic realities and site constraints), regulatory requirements (such as revisions to regulations and water quality standards), agreed-upon updates to the LTCP, or any number of unanticipated events. 11.4.1 Prioritization of Controls As defined in Section 11.2, the selected CSO controls include a number of individual projects. Each of these individual projects may, as the plan progresses, be further subdivided depending on many factors including, but not limited to, size, cost, complexity, location, capacity of the local workforce, and bidding climate. For example, a single storage tunnel may, when fully designed, be segmented into multiple construction contracts: • one or more tunnel construction contracts, • one or more contracts to construct drop shafts, vent shafts and deaeration chambers, • a tunnel dewatering pump station contract, • one or more contracts to modify CSO outfalls and diversion structures, and • one or more contracts to construct consolidation piping. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-26 February 2011 The prioritization and sequencing of the controls in the implementation schedule were based on a number of factors, including but not limited to: • Construction Sequencing. Engineering and construction requirements may dictate a particular sequence of activities in the implementation schedule. • Environmental Benefit. Projects which provide more environmental benefit, e.g., CSO volume reduction, received a higher priority in developing the schedule. • Concurrent Design and Construction. Some projects are complex and require long and involved design periods prior to beginning of construction. Other projects with less complicated designs could be built while the engineering progresses on the complex projects. • Cash Flow. Concurrent construction of projects must consider the matching of construction costs to available revenue. 11.4.2 Implementation Components An implementation schedule was developed for each of the LTCP controls. In general, the schedule for each control included the following activities as a minimum: • Project Scoping and Procurement of Design Consultant. These activities include the additional project definition needed for making final planning-stage decisions. Also included are activities to procure a design consultant, including the preparation and issuance of requests for qualifications, evaluation of the responses, preparation and issuance of requests for proposals, evaluation of the responses and selection of a consultant, fee negotiation, and the introduction and adoption of the necessary ordinances to authorize MSD to enter into a contract for engineering design services. • Preliminary Design. These activities typically include the conduct of initial geologic and geotechnical investigations, initial hydraulics studies and models, initial right-of-way studies and surveys, and the development of schematic layouts, sketches and preliminary design criteria. • Final Design. These activities consist of final geotechnical and hydraulic studies, selection of final alignments, establishment of final design criteria, and the development of contract documents (plans and specifications). • Permits and Right-of-Way Acquisition. These activities include the acquisition of necessary permits and approvals as well as the acquisition, through easement or condemnation proceedings, of the rights-of-way needed to construct the project. • Construction Contract Bid and Award. These activities include the advertisement of the project for bids, bidding period, evaluation of bids and selection of a contractor, and the introduction and adoption of the necessary ordinances to authorize MSD to enter into a construction contract. • Construction. These activities include the construction of the facilities in accordance with the contract documents and changes to the documents necessitated by differing field conditions, and oversight of the construction to ensure that the work conforms to the contract requirements. • Testing/Startup and Commissioning. These activities include testing of the various components of the work to verify that they perform as required, startup of the facilities to verify that components perform properly as systems, and final commissioning and construction contract closeout. 11.4.3 Scheduling Considerations Durations for the various activities included in the development of the implementation schedule were based on available information compiled during the planning process; experience on similar projects; estimated production rates; and mandatory bidding, procurement and land acquisition requirements. The actual times required to implement the LTCP may vary from the estimated times due to the size of the program (the largest public works program ever undertaken in Missouri); changes in laws, regulations and requirements; and unforeseen circumstances, particularly as the work involves a considerable Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-27 February 2011 amount of subsurface construction. Changes to any of the following may support a request for modification to the LTCP and the implementation schedule: • The Clean Water Act including the 1994 CSO Control Policy, • Various EPA guidance for CSO control, • Requirements for control of sanitary sewer overflows or stormwater discharges, • Missouri Clean Water Law, • Missouri Effluent Regulations, 10 CSR 20-7.015, • Missouri Water Quality Standards, 10 CSR 20-7.031, • Development of any Total Maximum Daily Loads for area waterways, • State Operating Permit MO-0025178 for Bissell Point Treatment Plant, • State Operating Permit MO-0025151 for Lemay Treatment Plant, • Future judgments, consent decrees or similar orders, • Financial Capability of MSD to finance the LTCP, • Timely approvals, permit acquisitions and land acquisitions, • Timely voter approval for issuance of bonds, • Additional information developed during preliminary and final design activities, • Estimated project capital costs and cost-escalation rates, • Other technical, legal and institutional conditions that require more time than anticipated or planned. 11.5 Post-Construction Compliance Monitoring Program The purposes of MSD’s post-construction compliance monitoring program (PCMP) are to determine the effectiveness of the CSO Long-Term Control Plan in meeting the performance objectives upon completion of the plan implementation, and to assess and document impacts on receiving waters resulting from implementation of CSO control measures. To further define the scope and conduct of the PCMP, MSD will prepare a Post-Construction Compliance Monitoring Program Plan, including a Water Quality Monitoring Plan. MSD will also develop detailed monitoring plans in advance of achieving full operation at each CSO treatment facility and storage device (in-line storage, tanks, and tunnels), and a stress test protocol to determine maximum treatable wet-weather flow rates for the Lemay Treatment Plant. Documentation of the PCMP will be provided in annual progress reports of LTCP implementation including the status of facilities (planning, design, construction, and in operation), implementation schedule status, and justification of any variance from that schedule, as needed. The annual report will include data and analysis, as available, on: • Final design criteria and sizing of the CSO control program elements, • CSO control measure performance (e.g., CSO activations and flow data), • Rainfall, • Receiving water quality, • Progress in updating and calibrating/validating the hydraulic models, • Status in achieving performance objectives based on continuous simulation of typical year, • Identification of variances from expected results, and • Proposed corrective action of LTCP program element(s), if needed. MSD will adapt the annual progress reports to provide the public with information on CSO program progress and performance and any water quality improvements. The reports are expected to be available on the District’s website, to interested organizations, and in meetings with interested parties. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-28 February 2011 11.5.1 Program Elements MSD’s PCMP consists of two major elements. The first element addresses the monitoring and sampling of CSO control measure performance, comparing of post-construction conditions with baseline conditions, and assessing of compliance with performance objectives. The second element addresses monitoring of improvements in water quality resulting from implementation of the control measures. 11.5.1.1 Performance Monitoring and Assessment The projected LTCP performance for each receiving water segment was based on the currently calibrated combined sewer system (CSS) hydraulic model using continuous simulations based upon the typical year (2000), and is expected to be achieved on a long-term average basis. The annual discharge frequency, or CSO volume reduction, will vary due to fluctuations in annual rainfall. As described above, the projected LTCP performance for each receiving water segment is shown in Table 11-5. Receiving Water Segment Control Alternative Level of Control1 Maline Creek Local treatment (Outfall 051) and local storage (Outfall 052) 4 Gingras Creek Outfall relocation 0 Upper River Des Peres Storage tunnel 4 River Des Peres Tributaries Conveyance/storage tunnel 4 Lower & Middle River Des Peres Storage tunnel, in-sewer storage, local treatment at Outfall 063 4 Mississippi River Controls on tributary streams as noted above and enhanced green infrastructure program Note 2 Notes: 1. Defined as number of overflows in the typical year (year 2000). 2. Control of overflows to the Mississippi River will be achieved through the performance of the controls on the tributary streams noted above, previously-implemented CSO control measures, and the enhanced green infrastructure program implemented in combined sewer areas tributary to the Mississippi River. Table 11-5 Projected LTCP Performance During implementation of the CSO LTCP, MSD will continue to monitor rainfall volume and intensity. This information will be used in conjunction with the CSS hydraulic model to update CSO discharge volume and duration estimates. As facilities and additional monitoring equipment are placed into service during program implementation, localized activation, flow and storage facility volume (discharge and return to treatment) monitoring will be conducted and the CSS hydraulic model will be updated, as needed. The updated CSS hydraulic model may be used in developing final design criteria and sizing of each LTCP element. The rainfall, flow monitoring, and CSO activation data collection will be reviewed and utilized in accordance with the data quality assurance measures outlined in MSD’s Hydraulic Model Development Report, July 11, 2007. In the event that normal, accepted practices related to the proposed data collection have changed (e.g. due to advances in technology) an alternate method will be developed and submitted for approval. During the period that data is being collected, MSD will update the CSS hydraulic model to reflect the LTCP implemented CSO controls and other changes in the collection system that differ from the then existing version of the collection system model. At this juncture, it is assumed that accepted engineering Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 11. SELECTED PLAN Page 11-29 February 2011 practice at the time the PCMP is conducted will still rely on a CSS model similar to those in use today. In the event that accepted practice at the time the PCMP is conducted has changed, MSD will submit an alternate method for approval. Once sufficient data has been gathered and evaluated, the data will be used to calibrate and validate the model as outlined in MSD’s Hydraulic Model Development Report, July 11, 2007, or approved alternate method. The calibration and validation efforts will be submitted as part of the PCMP. In the event that model calibration and validation is not successful, MSD will submit a supplemental program to gather additional data and recalibrate/validate the CSS model. This step will be performed until a calibrated and validated model is achieved. Lastly, using the calibrated CSS model, the typical year (year 2000) precipitation data will be run through the model as a continuous simulation. The results from the continuous simulation will be compared with the level of control proposed for each receiving water segment, as provided in Section 11 of the LTCP. 11.5.1.2 Water Quality Monitoring MSD’s Water Quality Monitoring Plan will define a program that will further characterize baseline water quality, measure changes in water quality during and after the LTCP is implemented, and assess impacts of remaining CSOs following implementation of the plan’s CSO control measures. As a minimum, the water quality monitoring program will employ same monitoring sites that were used to establish baseline conditions during the development of the LTCP. Data from other agencies may be incorporated into the program if the data are considered by MSD to be of acceptable quality. Samples will be taken at defined times and analyzed for E. coli and other filed parameters and pollutants of concern as identified in the Water Quality Monitoring Plan. The data will be collected, reviewed and utilized in accordance with MSD’s data quality assurance measures. 11.5.2 Control Program Performance Measures Performance of MSD’s CSO LTCP was based upon the level of control summarized in Table 11-5 above. Using the approved (calibrated and validated) CSS model, the fully implemented LTCP is projected to result in those levels of control based upon the selected typical year continuous simulation. This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-1 February 2011 12. GREEN INFRASTRUCTURE PROGRAM 12.1 Introduction As described in Sections 8.4.7 and 11.2.7 of this report, MSD’s selected combined sewer overflow (CSO) control alternative involves cost-effective gray infrastructure for urban streams and an enhanced green infrastructure program for CSOs that are directly tributary to the Mississippi River. This section of the Long-Term Control Plan (LTCP) describes the green infrastructure program for reduction of CSOs, particularly for the Mississippi River CSOs where extensive redevelopment is forecasted. Gray infrastructure controls will reduce untreated overflows to Maline Creek and the River Des Peres to an average of four events in a typical year. These controls will also significantly reduce CSO loadings to the Mississippi River. As presented in Section 8, gray infrastructure for Mississippi River CSOs requires a minimum expenditure of $1 billion and perhaps as much as $4.3 billion. Also, as discussed in Section 3, water quality standards are met in the Mississippi River under existing conditions. The selected alternative therefore primarily uses green infrastructure controls for CSOs that discharge to the Mississippi River. Successes with these efforts will also be considered for other locations within MSD’s service area. Green infrastructure refers to constructed projects that re-direct stormwater from reaching sewers by capturing and diverting it to locations where it is detained, infiltrated into the ground, evaporated, taken up by plants, or reused. The use of plant materials to facilitate uptake and improve stormwater quality makes these practices literally green; their ability to provide more sustainable wet weather flow management by reducing energy consumption and carbon footprint makes them figuratively green. MSD’s selected alternative includes $100 million in green infrastructure investments over a period of 23 years to reduce CSOs and improve water quality. This amounts to a green infrastructure investment equivalent to 5.5 percent of MSD’s CSO control investment, which is in the range of green infrastructure investment that other Midwestern utilities are making in their CSO control plans. For example, Sanitation District No. 1 of Northern Kentucky has proposed green infrastructure investment valued at about 3.5 percent of their total program cost and Kansas City, Missouri has proposed green infrastructure investment worth approximately 8 percent of their planned program. The overall objective for MSD’s green infrastructure program is to identify and implement projects and programs that will significantly reduce CSOs and provide additional environmental benefit. A program goal is to reduce CSO overflow volumes to the Mississippi River by 10 percent. This goal will be updated based on the results of projects comprising the pilot phase of the program. A successful model for implementation of a green infrastructure program will incorporate some adaptive management components, whereby data will be used to evaluate performance and these data will inform future decisions about refining the green infrastructure approaches. 12.1.1 Reasons for Incorporating Green Infrastructure in MSD’s LTCP MSD will use green infrastructure as part of the LTCP as an effective component of an overall water quality improvement strategy for the following reasons: EPA promotes the use of green infrastructure in CSO LTCPs; green infrastructure practices can be economical, environmentally-friendly, and sustainable complements to traditional CSO control techniques; and the public supports a measured green infrastructure program. In addition to being a potentially significant element of MSD’s CSO control program, there are a number of additional reasons for incorporating green infrastructure into MSD’s CSO control plan, including those described below. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-2 February 2011 12.1.1.1 US EPA Endorsement of Green Infrastructure The U.S. Environmental Protection Agency (EPA) and other organizations published a Statement of Support for Green Infrastructure in 2007 to bring together organizations that recognize the benefits of the use of green infrastructure to mitigate sewer overflows and reduce stormwater pollution (EPA et al., 2007). EPA encourages implementation of green infrastructure in CSO, SSO, and stormwater programs. EPA’s goals for green infrastructure implementation include: • Development of models to quantify stormwater storage and infiltration potential. • Monitoring to verify CSO, SSO, and stormwater discharge reductions. • Quantification of life-cycle costs. • Increased federal, state, and local funding for green infrastructure initiatives. • Elimination of barriers to the incorporation of green infrastructure in sewer programs. • Preparation of guidance documents to assist in the development of green infrastructure initiatives. • Development of green infrastructure programs to incorporate into CSO and SSO permits, management, operations, maintenance plans, and consent decrees. EPA is promoting the use of green infrastructure particularly in urban environments where the environmental damage associated with traditional development is more extensive (EPA, 2009). The incorporation of green infrastructure into MSD’s LTCP supports EPA’s endorsement of green infrastructure for wet weather planning. 12.1.1.2 Ancillary Benefits of Non-Conventional Solutions to CSO Control Green infrastructure implementation is considered a non-conventional approach to CSO control because it is a fairly recent concept in comparison to traditional gray infrastructure systems. Its implementation as part of major cities’ long-term control plans has occurred only in the past few years. Nonetheless, in addition to reducing wet weather flows, green infrastructure solutions to CSO control can have many ancillary benefits. These benefits can include supplementing redevelopment efforts, helping to alleviate CSO funding constraints, and providing aesthetic, educational, and recreational benefits to communities. As such, the inclusion of green infrastructure as an appropriate element of CSO LTCPs is becoming increasingly common. One aspect of green infrastructure that makes it appropriate for use in CSO long-term control planning is the fact that it can be readily incorporated into urban development and redevelopment. Integration of green infrastructure into these projects is often more economical than retrofitting existing properties and it can offset the increased wet weather loads that conventional development/redevelopment projects create. EPA concluded in a recent study (Field, 2009) that even as stand-alone projects, green solutions can in many cases be implemented less expensively than conventionally engineered drainage systems. Major costs of green infrastructure are acquisition of land and system installation (Field, 2009). Green solutions can provide insulation for buildings and mitigate urban heat island effects, decreasing utility costs. Conventional systems can be less expensive initially, but require more in terms of maintenance. The overall life cycle cost of green technology can therefore be much less. Finally, green infrastructure provides benefits beyond runoff reduction. Green solutions are generally viewed as more aesthetically pleasing than traditional stormwater conveyance systems. Landscape features including shrubs, grass, herbs, and wildflowers can be part of systems that manage runoff. Green infrastructure adds green space to cities, increases recreational opportunities, creates wildlife habitat, increases groundwater recharge, improves air quality, increases property values, enhances urban quality of life, and improves human health (EPA, 2009). Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-3 February 2011 12.1.1.3 Public Support for Green Infrastructure The public engagement and stakeholder involvement process undertaken by MSD as part of the LTCP development indicates that there is widespread public and stakeholder support for green infrastructure. The public engagement process included: 1) key stakeholder interviews, 2) the establishment of a Stakeholder Advisory Committee, 3) stakeholder and community presentations, and 4) public open houses. Overall, the purpose of these activities was to educate the public about existing sewer conditions and the sewer overflow issue; review options for reducing combined sewer overflows; identify the public’s preferred options; and explore opportunities for additional action by MSD and the public. Some details of the public input process related to green infrastructure are discussed below. Stakeholder Advisory Committee During their consideration of CSO control options, the Stakeholder Advisory Committee members voiced support of a general watershed approach to implement green infrastructure as part of the LTCP. They emphasized the need to complete preliminary research and appropriate a portion of the budget for testing the effectiveness of green infrastructure. The Committee also favored minimizing “greenwashing,” a term used to describe the practice of spinning products and policies as environmentally friendly when they are not, a deceptive use of green marketing. The stakeholders were also concerned about the high cost of traditional controls for CSOs discharging to the Mississippi River. The committee instead supported aggressive green infrastructure implementation for these CSOs. However, the committee recognized the need to research information and monitor effectiveness to identify the most effective practices so that money was not wasted on ineffective practices. Public Open Houses MSD has documented the results of their 13 public open house sessions designed to involve the public and gauge their opinions on MSD’s CSO mitigation efforts and LTCP contents. During this process, the public expressed their preference for “Knee-of-Curve on Urban Streams plus Enhanced Green Program on the Mississippi River” as the level of control MSD should implement as part of its LTCP. The following were prioritized as most important: 1) make waterways safer for the people who use or live by them; 2) reduce the frequency of sewer overflows; 3) keep sewer rates as affordable as possible; 4) make waterways healthier for fish/wildlife; and 5) include green infrastructure as part of the project. The public’s comments on actions they would like MSD to take can be broadly categorized into education, working with others, and funding: Education • Provide brochures and educational programs to promote rain barrels, porous pavement, and other green infrastructure practices, as bill inserts. • Educate school children, and increase public service announcements on radio and TV as well as segments on local news. • Provide consistent and continuous communication of MSD’s actions and dangers of inaction. • Document the success or failure of green infrastructure demonstration projects, and make this information available to the public. Working with Others • Work with developers to implement construction practices that decrease runoff. • Work with cities to use rain gardens for street medians. • Work with highway departments to reduce runoff. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-4 February 2011 Funding • Increase sewer bill rates modestly to fund CSO elimination measures. • Seek federal or other matching grants. • Along with green roofs and pervious pavement, issue a credit on stormwater bills for a customer’s rain gardens and rain barrels. • Provide incentives so that the public’s cost of green infrastructure implementation is low. • Charge much higher rates for large volume industrial users. • Some members of the public believe that green infrastructure measures are too costly, and that St. Louis should not try to comply with the EPA’s CSO requests. In general, the Stakeholder Advisory Committee’s and the public’s comments align well. Both emphasize a desire for more green practices, public outreach and education opportunities, and partnerships to alleviate costs. The public is in favor of green infrastructure implementation as part of the LTCP as long as the projects do not put a great deal of a financial burden on the ratepayers. The public would like to become more educated on how they can be involved in the effort to implement green infrastructure into their homes and businesses. Some parties would like green infrastructure expanded to the entire MSD service area, not just the combined sewer service area. 12.1.2 The Role of Green Infrastructure in MSD’s LTCP To reduce CSOs, MSD must establish waterway priorities and identify the option or Level of Control that best carries out these priorities (see Section 8.1). MSD, the Stakeholder Advisory Committee and the public considered five Levels of Control. Two of the scenarios involve the expandability of CSO controls to include green infrastructure. The selected alternative, Scenario 3 (Knee-of-Curve on Urban Streams plus Enhanced Green Program on the Mississippi River), involves some of the funding for gray infrastructure practices being diverted to green infrastructure initiatives. This scenario was developed due to stakeholders’ concern about the high cost of traditional controls for CSOs discharging to the Mississippi River. Significant opportunities for green infrastructure implementation exist in the areas tributary to the Mississippi River, including the Bissell Point and Lemay service areas. Features include large impervious parking areas that could be converted to green parking and significant amounts of vacant or abandoned property that can be retrofitted to reduce stormwater volumes reaching the combined sewer system (CSS). 12.2 Potential Green Infrastructure Opportunities in MSD’s CSS Area MSD commissioned a preliminary study of green infrastructure in the Bissell Point service area to evaluate the potential for green infrastructure to reduce discharges from 11 target CSOs representing approximately 90% of the total average annual CSO volume from the Bissell Point CSS (LimnoTech, 2009). The study was used to identify green infrastructure techniques that may be applicable in the main Bissell Point CSO drainage areas. The study also identified retrofit opportunities and their potential to reduce CSO volumes and peak rates. There are several significant challenges in implementing these green infrastructure measures, chiefly because opportunities for green infrastructure are, for the most part, located on property that is not owned by MSD. The study found that the green infrastructure techniques that are likely to be most applicable in MSD’s CSS areas include green roofs, bioretention, green streets, green parking retrofits, rain barrels, and site- scale and neighborhood-scale stormwater retrofitting. Because of the soil types in the CSS areas, rapid infiltration techniques are not recommended and are therefore not presented as part of the LTCP. Site- scale and neighborhood-scale stormwater retrofitting are particularly attractive techniques in that they Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-5 February 2011 take advantage of redevelopment of vacant and underused properties that are owned by the Land Reutilization Authority (LRA). The LRA is an agency of the City of St. Louis whose mission is to acquire properties that have undergone tax foreclosure and facilitate their transition back to productive use. Three of the eleven target CSO drainage areas studied (037 Palm, 038 Branch, and 047 Harlem) appear to have the greatest potential for green infrastructure to reduce CSO. These drainage areas contain large amounts of LRA lands, with Harlem having the most. Also, CSO drainage area 016, Old Mill Creek, located in downtown St. Louis, is able to yield a significant CSO response due to reductions in imperviousness despite the restriction on the amount of land available for stormwater retrofits. Aerial photography was used to identify the types of opportunities appropriate in each drainage area. GIS was used to quantify areas, distances, and counts of relevant features to allow estimation of green infrastructure benefits in reducing imperviousness. Details will vary block to block in each of these service areas. The 11 CSOs that were studied are estimated to discharge a total of 108 million gallons in a 4 month synoptic storm. If all of the green infrastructure retrofit measures outlined in the report were implemented, this volume could be reduced by approximately 12.5 million gallons (11.6%). In addition, supplemental hydraulic modeling of the Harlem CSO (Outfall 047) drainage area was conducted to evaluate annual CSO volume reduction. This supplemental analysis indicates that reduction of impervious areas through green infrastructure has the potential to significantly reduce CSO volume during a typical year (see Figure 12-1). The example in Figure 12-1 shows that a 20% reduction in imperviousness in the Harlem CSO drainage area could result in an annual CSO volume reduction of 225 million gallons and a peak overflow reduction of 229 million gallons per day. Based on these findings, it can be concluded that green infrastructure has the potential to substantially contribute to CSO control and to potentially reduce the size of traditional control measures. Further work is needed to validate these results, identify specific project opportunities, and develop estimates of project costs, but the preliminary results indicate that green infrastructure can significantly reduce some CSOs. 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 0 200 400 600 800 1000 1200 0% 5% 10% 15% 20% 25% 30% 35% 40% 45%CSO Peak Flow (MGD)CSO Volume (MG)Impervious Reduction Modeled Annual Reductions in the Harlem CSO (047) CSO Volume (MG)CSO Peak Flow (MGD) Figure 12-1 CSO Volume Reduction in the Harlem CSO Drainage Area Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-6 February 2011 12.3 The St. Louis Green Infrastructure Program MSD is planning an ambitious $100 million green infrastructure program over the next 23 years to complement gray infrastructure investment. The planned program is described in this section and consists of: • Leadership • Public education and outreach • Continuation of the rain barrel program • Completion of ongoing projects • A stormwater retrofitting program utilizing green infrastructure 12.3.1 MSD as a Green Infrastructure Leader Leadership is important to promote the acceptance and use of green infrastructure in the St. Louis community. Although the focus of green infrastructure investment as part of the LTCP will naturally be in the combined sewer service area, there is potential for evaluating green infrastructure elsewhere. It is likely that efforts could result in water quality improvements in receiving waters outside of the combined sewer service area, as well. MSD will use resources to evaluate the benefits of green infrastructure throughout its entire service area by implementing projects and programs, monitoring their outcomes, and publicizing the results. Sharing of information about these projects and programs will not only educate others about green infrastructure but will also provide information needed for wider scale implementation of these practices in the St. Louis area. 12.3.2 Public Education and Outreach MSD will involve the public in the process of implementing green infrastructure practices via education and engagement, as public support for these programs and projects has high importance. In addition, monthly stormwater fees are expected to increase from the current $0.14 per 100 square feet of impervious surface1. These fees will continue to fund much-needed wet weather controls throughout MSD’s service area. Public education will be important in explaining the rate increases and will provide a vehicle to show ratepayers how they can reduce their stormwater bill through their own green infrastructure projects. Several public outreach and education programs currently exist that can be leveraged to enhance public outreach, education, and involvement in green infrastructure, including the following: • ShowMe Rain Gardens Partners – MSD is currently partnered with the Soil & Water Conservation District of St. Louis, Missouri Botanical Garden, local governments, conservation agencies, private citizens, and corporations in the ShowMe Rain Gardens Program, a regional water quality initiative focused on promoting rain gardens as a means to water quality improvement and the mitigation of adverse stormwater impacts. MSD intends to continue this partnership and leverage it to promote green infrastructure throughout its service area. • Stream Teams – Three thousand Stream Teams have been established state-wide with an estimated 60,000 members working to improve nearly 15,000 miles of adopted local streams. Past Stream Team projects have been chosen according to each Team’s interests and local needs. Some pick up trash, plant trees, or stencil storm drains, while others monitor water quality or help educate their community. Biologists trained in stream management and water quality are available to provide guidance and answer questions. The program is sponsored by the Missouri Department of Conservation, the Missouri Department of Natural Resources, and the Conservation Federation of Missouri. MSD coordinates 1 A recent challenge and adverse judgment over MSD’s impervious surface stormwater fees have created uncertainty over plans for future stormwater fees. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-7 February 2011 with these agencies and the Stream Teams, and will educate them about the benefits of green infrastructure and encourage the Teams to implement “grass roots” green infrastructure projects. • Clean Rivers Healthy Communities Program – MSD’s Clean Rivers Healthy Communities Program encourages the public to become part of the CSO control solution. The program is a multi- decade, multi-billion dollar initiative designed to improve the quality of the area’s rivers, streams, and creeks. The program offers an info-line at 314-768-CRHC and an informational website at www.cleanriversstl.com. The site gives residents, business owners, and municipalities, ways to implement green infrastructure techniques to become part of the Clean Rivers solution. MSD encourages the public to invite Clean Rivers representatives to present at local neighborhood or organizational meetings; attend public open houses; and participate in a Stream Team or Household Hazardous Waste Collection Events. This program will be used to provide green infrastructure education and to promote green infrastructure projects. • MSD Public Open Houses – As part of the Clean Rivers Healthy Communities Program, MSD conducted 13 open houses designed to educate the public about MSD’s CSO control efforts as well as ascertaining the public’s preferences regarding MSD’s establishment of waterway priorities and selection of wet weather overflow controls. The project team sought to maximize participation in the open houses by organizing meetings across the region – five in St. Louis City and eight in St. Louis County. Members of the public unable to attend one of the 13 open houses could participate virtually through an online forum. This successful format will be continued to provide information and to obtain public feedback on green infrastructure projects. • Landscape Guide for Stormwater Best Management Practices – MSD has developed the Landscape Guide for Stormwater Best Management Practice Design for St. Louis. This guide covers topics such as invasive species, site preparation, planting design, plant selection, installation, management and landscaping criteria, and plant selection for stormwater BMPs including wet ponds, wetlands, infiltration basins, dry swales, surface sand filters, bioretention, and organic filters. The guide will be updated to aid landscapers and developers in implementing green infrastructure practices. • St. Louis County Phase II Stormwater Management Plan – The St. Louis County Phase II Stormwater Management Plan outlines a public education program that involves the distribution of educational materials to the community, outreach activities relating to the impacts of stormwater discharges on water bodies, and steps the public can take to reduce pollutant loadings in stormwater runoff. MSD, the coordinating authority under the permit, has completed the following public outreach initiatives (MSD, 2007): – Distributing brochures on pet waste management, yard waste, impacts from businesses, and more. – Sponsoring a stormwater school article contest. – Developing a stormwater pollution prevention video. – Airing four stormwater infomercials. – Conducting seminars for small businesses. • Other Environmental Groups – In addition to the groups and programs outlined above, MSD plans to communicate with other environmental groups including, but not necessarily limited to, the River Des Peres Watershed Coalition and the Missouri Coalition for the Environment. 12.3.3 Rain Barrel Program As part of the Phase II Stormwater Management Plan involving pollution prevention, MSD has offered its customers the opportunity to reduce stormwater runoff by purchasing 55-gallon rain barrels to collect and store rainwater. The pilot program offered rain barrels for $45, limiting orders to four barrels per customer. Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-8 February 2011 The MSD rain barrel program drew an overwhelming response, with the District selling 1,558 barrels during the spring of 2009. This was more than five times the expected number of sales. MSD again offered rain barrels for sale to the public in 2010 with 1,210 units sold. Because of the overwhelming success of this program, and the potential for rain barrels to reduce residential runoff, MSD plans to extend the program as part of their overall wet weather control planning effort. 12.3.4 Ongoing Projects Several projects are already being conducted by MSD or with MSD’s involvement that incorporate elements of green infrastructure, including those described below. 12.3.4.1 Permeable Pavement Project The City of St. Louis Board of Public Service formed a partnership with MSD, the Missouri Department of Conservation, CH2M Hill, Southern Illinois University (SIUE), and East-West Gateway Council of Governments in mid-2007 to find ways to incorporate low impact development techniques into City of St. Louis projects. The team identified pervious paving as the first best management practice (BMP) to investigate due to the multiple benefits it provides and the ample opportunity to utilize the practice in City-owned projects (Yates, 2009). The City of St. Louis has approximately 485 miles of alleys, and is seeking to develop an alley replacement program to provide for pervious pavements to be constructed in lieu of the more conventional asphalt or concrete pavements. This study aimed to evaluate the effectiveness of porous pavement on flow reduction and water quality improvement in combined sewers. The flows and water quality of samples taken from combined sewers at three alleys in the City of St. Louis are to be compared before and after porous pavements are implemented. The project consists of three phases: Phase I to monitor and characterize the flows and water quality under existing conditions; Phase II to design and construct the porous pavement; and Phase III to monitor and characterize the flows and water quality under improved conditions where low impact development has been implemented. The three pilot alleys were identified and equipment was installed to measure stormwater quantity and quality along with rainfall from May to July 2008. Results are currently being processed by SIUE. Phase II construction began with the permeable asphalt alley, which was completed in October 2008. Funding for the pervious concrete alley is being provided by the Ward 6 Alderwoman, Kacie Starr-Triplett. Funding is still being secured for construction of the permeable paver alley. This pilot study data will be used to support a change in City of St. Louis policy to potentially require pervious paving in its alleys citywide. The data will also be used to promote change in private developments and other City paving projects where appropriate. The results will be used by MSD to determine if permeable pavements can be used as a BMP either in junction with other BMPs or as a stand-alone BMP. 12.3.4.2 Horseshoe Project In 1952, prior to the formation of MSD, the City of St. Louis conducted a study to address flooding issues in the Harlem and Baden watersheds. The study recommended construction of a relief tunnel system that would intercept flow from the four main trunk lines and convey the intercepted flow to the Mississippi River. The City was unable to acquire sufficient funds to construct the relief tunnel. After a similar 2003 study conducted by Black & Veatch, the District requested the firm to develop a master plan to identify less expensive projects that could address local area flooding issues to be incorporated Metropolitan St. Louis Sewer District CSO LTCP Update SECTION 12. GREEN INFRASTRUCTURE PROGRAM Page 12-9 February 2011 into the overall relief plan for the Harlem and Baden watersheds. The Hebert Stormwater Detention Basin and Sewer Separation project was identified as such a project. The Hebert Stormwater Detention Basin and Sewer Separation Project (the Horseshoe Project) offers dual benefits to the community in terms of reduced volume and frequency of CSOs and local flooding. The project involves stormwater detention, which results in stormwater being released slowly into the CSS, as well as some sewer separation. The site is located south of Interstate 70 approximately eight miles northwest of downtown St. Louis, within the Harlem and Baden watersheds. The stormwater detention basin will be located in the City of St. Louis, at the confluence of the 12 foot horseshoe-shaped South Harlem Trunk Sewer (upstream drainage area 841 acres) and an 8 foot diameter tributary combined sewer (upstream drainage area 311 acres). Sewer separation will occur in the catchment area served by the 8 foot diameter tributary sewer. MSD is conducting a study to provide a preliminary design to separate stormwater runoff from the existing combined trunk sewers and detain 20 year stormwater runoff in a new proposed detention basin at the downstream end of the project area. The proposed detention basin will be approximately nine acres and have a capacity of 2,463,500 cubic feet. The basin will detain stormwater runoff from the 311 acre catchment area currently served by an existing 8 foot diameter combined sewer. The project is estimated to cost $26 million. Currently, property acquisition is underway. A church owns several of the properties needed by MSD. These properties have parking lots on them. MSD is planning to buy replacement properties, build pervious parking lots on them, and conduct a property exchange with the church. A preliminary sketch of the proposed parking lot layout has been drafted by MSD. The parking lots are estimated to be built within a year. Preliminary designs of the sewer separation and detention basin have been drafted. MSD anticipates an 18 month final design period followed by construction beginning several years from now. 12.3.5 Stormwater Retrofitting Green Infrastructure Program One of the challenges to implementing green infrastructure that has been identified is that MSD does not own the property where green infrastructure could be implemented. Also, while MSD has qualified legal authority to require detention and control release rates, local municipalities have legal authority for other land use/zoning regulations that influence the generation of stormwater. MSD has been actively working to meet these challenges, and is presently engaged with parties that would allow for a large number of site-scale and neighborhood-scale stormwater retrofitting projects under MSD’s $100 million commitment to green infrastructure. An initial 5-year pilot program commits a minimum of $3 million to perform stormwater retrofitting utilizing green infrastructure on properties currently owned by the Land Reutilization Authority. A diversity of green infrastructure practices will be used to build implementation experience and evaluate the performance of various types of practices. The pilot program will include monitoring of selected projects to evaluate performance of the green infrastructure controls. The pilot program is intended to test and resolve the numerous anticipated regulatory, logistical and financial aspects of the projects among the multiple stakeholders. The pilot program will also provide data to inform development of the full-scale implementation of the green infrastructure program. Appendix Q provides additional details of the program. This page is blank to facilitate double-sided printing. References Page 1 February 2011 Association for the Advancement of Cost Engineering Recommended Practice No. 17R-97. 1997. Cost Estimate Classification System. August 12, 1997. Bicknell et al. 2005. HSPF Version 12.2 User’s Manual. AQUA TERRA Consultants. In Cooperation with Office of Surface Water, Water Resources Discipline, U.S. Geological Survey, Reston, Virginia and the National Exposure Research Laboratory, Office of Research and Development. Boyd, Sarah. 2007. Personal communication with S. Boyd, Plant Manager, Illinois American – East St. Louis. East St. Louis, Missouri. May 7, 2007. Burton, Ken. New Hope for the Pallid Sturgeon. Endangered Species Bulletin. Vol. XXV, No. 1-2, pp. 4-5. http://www.fws.gov/endangered/esb/2000/01-04/04-05.pdf. Accessed May 1, 2007. Chapra, S.C. 1997. Surface Water-Quality Modeling. McGraw Hill. 1997. EPA. 1976. Cost Estimating Manual- Combined Sewer Overflow Storage and Treatment, EPA 600-2- 76-286. December 1976. EPA. 1981. Construction Costs for Municipal Wastewater Conveyance Systems: 1973-1979, EPA 430- 9-81-003. January 1981. EPA. 1989. National Combined Sewer Overflow (CSO) Control Strategy. 54 Federal Register 37370. September 8, 1989. EPA. 1993a. Combined Sewer Overflow Control Manual, EPA 625-R-93-007. September 1993. EPA. 1994. CSO Control Policy. 59 Federal Register 18688. April 19, 1994. EPA. 1995. Combined Sewer Overflows Guidance for Long-Term Control Plan. EPA 832-B-95-002. September 1995. EPA. 1997. Combined Sewer Overflows Guidance for Financial Capability Assessment and Schedule Development. EPA 832-B-97-004. March 1997. EPA. 2001. Guidance: Coordinating CSO Long-Term Planning with Water Quality Standards Reviews. EPA 833-R-01-002. July 2001. EPA. 2004. Report to Congress: Impacts and Control of CSOs and SSOs. August 2004. EPA, NACWA, NRDC, LID, and ASIWPCA. 2007. Green Infrastructure Statement of Intent. April 19, 2007. EPA. 2009. Managing Wet Weather with Green Infrastructure. References Page 2 February 2011 Field, Richard. 2009. Demonstration of Green/Gray Infrastructure for CSO Control. Aging Water Infrastructure (AWI) Research. US EPA. Retrieved July 16, 2009, from http://www.epa.gov/nrmrl/wswrd/awi/projects/demo_csocontrol.html. Fischer, H.B., E.J. List, R.C.Y. Koh, J. Emberger and N.H Brooks. 1979. Mixing in Inland and Coastal Waters. Academic Press, Inc. San Diego, California. Hummel, P., Kettle, J. Jr. and M. Gray. 2001. WDMUtil 2.0, A Tool for Managing Watershed Modeling Time-Series Data User’s Manual. AQUA TERRA Consultants, Decatur, Georgia. EPA Contract No. 68-C-98-010. Work Assignment No. 2-05. Health Protection and Modeling Branch Standards and Health Protection Division, Office of Science and Technology, Office of Water, U. S. Environmental Protection Agency, Washington DC. IEPA. 2001. Source Water Assessment Program Fact Sheet, Illinois American Water Company – East St. Louis, St. Clair County. Prepared in Cooperation with the U.S. Geological Survey. 35 pages. August 6, 2001. Jacobs Civil Inc. 2006. CSO Flow and Pollutant Characterization Report. January 26, 2006. Jacobs. 2007. Draft Hydraulic Model Development Report: Update to December 1996 Characterization, Monitoring, and Modeling Report. July 11, 2007. Kuska, Heidi. 2007. Personal communication with H. Kuska, USFWS, Columbia, Missouri. April 17, 2007. Limno-Tech. 2006. Final Water Quality Study Report: CSO Long-Term Control Plan Update. August 30, 2006. Limno-Tech. 2006. Receiving Water Model Development: CSO Long-Term Control Plan Update. September 27, 2006. Limno-Tech. 2009. Evaluation of Potential Effectiveness and Feasibility of Green Infrastructure for Combined Sewer Overflow Control in the Bissell Point Service Area, St. Louis, MO. Macy, William. 2009. Personal communication with B. Macy, MDNR Water Protection Program, Jefferson City, Missouri. June 17, 2009. Metropolitan St. Louis Sewer District. 2007. St. Louis County Phase II Storm Water Management Plan: Second Permit Term 2008 – 2013. Prepared for St. Louis County Municipalities by the St. Louis Municipalities Phase II Storm Water Planning Committee. Retrieved June 17, 2009, from http://mkasmtp1.stlmsd.com/portal/page/portal/MSD/PgmsProjs/PhaseII/PHASE_II_MASTER_0.pdf Missouri Department of Conservation (MDC). 2007. Heritage Review Report. Prepared by Shannon Cave. March 20, 2007. References Page 3 February 2011 MDC. 2000a. Best Management Practices Peregrine Falcon (Falco peregrinus). http://www.mdc.mo.gov/documents/nathis/endangered/p_sturgeon.pdf. September 2000. MDC. 2000b. Best Management Practices Pallid Sturgeon (Scaphirhynchus albus). http://www.mdc.mo.gov/documents/nathis/endangered/p_sturgeon.pdf. April 2000. Missouri Department of Natural Resources (MDNR). 2000. Missouri Drinking Water Source Water Assessment Plan. http://drinkingwater.missouri.edu/swap/#section%20III. Accessed March 23, 2007. MDNR. 2004. Recreational Use Attainability Analysis Protocol. Missouri Department of Natural Resources. Water Protection Program. November 3, 2004. MDNR. 2008. Title 10 of the Missouri Code of State Regulations. Division 20, Chapter 7.031. Water Quality Standards. July 31, 2008, and revisions approved by the Missouri Clean Water Commission on July 1, 2009. MDNR. 2009. Methodology for the Development of the 2010 Section 303(d) List in Missouri. Prepared by the Division of Environmental Quality, Water Protection Program. Approved by the Missouri Clean Water Commission. May 6, 2009. MEC Water Resources. 2005. Maline Creek Whole Body Contact Recreation Use Attainability Analysis. Report prepared for MSD. July 2005. MEC Water Resources. 2005. Mississippi River Whole Body Contact Recreation Use Attainability Analysis. Report prepared for MSD. July 2005. MEC Water Resources. 2005. River Des Peres Whole Body Contact Recreation Use Attainability Analysis. Report prepared for MSD. July 2005. MEC Water Resources. 2007. Mississippi River Whole Body Contact Recreation Use Attainability Analysis. Report prepared for MSD. October 11, 2007. National Oceanic and Atmospheric Administration (NOAA). 2007. http://sanctuaries.noaa.gov/welcome.html. Accessed April 2, 2007. Pallid Sturgeon Recovery Team. 1993. Recovery Plan for the Pallid Sturgeon (Scaphirhynchus albus). Principal Authors: M.P. Dryer and A.J. Sandvol. Prepared for the USFWS Region 6. Denver, Colorado. http://fwp.mt.gov/fwppaperapps/wildthings/plsRecoveryPlan.pdf. Accessed April 2, 2007. References Page 4 February 2011 Quist, M. C., A. M. Boelter, J. M. Lovato, N. M. Korfanta, J. L. Bergman, D. C. Latka, C. Korschgen, D. L. Galat, S. Krentz, M. Oetker, M. Olson, C. M. Scott, and J. Berkely. 2004. Research and Assessment Needs for Palled Sturgeon Recovery in the Missouri River. Final report to the U.S. Geological Survey, U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, and U.S. Environmental Protection Agency. William D. Ruckelshaus Institute of Environment and Natural Resources, University of Wyoming, Laramie. Sanks, Robert L. 1989. Pumping Station Design. Butterworth Publishers, Stoneham, MA. Sverdrup Civil, Inc. 1996. Combined Sewer Overflow Management Plan: Characterization, Monitoring, and Modeling Program. December 1996. Sverdrup. 1999. Metropolitan St. Louis Sewer District Combined Sewer Overflow Long Term Control Plan. June 1999. Wilkison, D. H., and Davis, J. V. 2010. Occurrence and Sources of Escherichia Coli in Metropolitan St. Louis Streams, October 2004 through September 2007. USGS Scientific Investigations Report 2010-5150. Yates, Dave and Marjorie Melton. 2009. City of St. Louis Permeable Pavement Alley Pilot Study. World Environmental and Water Resources Congress 2009:Great Rivers. ASCE. Acronyms Page 1 February 2011 BOD5 Five Day Biochemical Oxygen Demand CBOD Carbonaceous Biochemical Oxygen Demand COD Chemical Oxygen Demand CSO Combined Sewer Overflow CWA Clean Water Act DARF Depth Area Reduction Factor DO Dissolved Oxygen EHRC Enhanced High Rate Clarification EMC Event Mean Concentration ENR Engineering News Record EPA or USEPA United States Environmental Protection Agency GARR Gage Adjusted Radar Rainfall gpm Gallons per Minute I/I Inflow and Infiltration IAWC Illinois American Water Company IEPA Illinois Environmental Protection Agency LRDP Lower River Des Peres LTCP Long-Term Control Plan MCWC Missouri Clean Water Commission MDC Missouri Department of Conservation MDNR Missouri Department of Natural Resources MG Million Gallons MGD Million Gallons Per Day MRDP Middle River Des Peres MSD or District Metropolitan St. Louis Sewer District NFR Non-Filterable Residue NMS National Marine Sanctuary NPDES National Pollutant Discharge Elimination System NWS National Weather Service O&M Operation and Maintenance ONRW Outstanding National Resource Waters ORS Overflow Regulation System POTW Publicly Owned Treatment Works PR Photosynthesis and Respiration RDP River Des Peres SCR Secondary Contact Recreation SOD Sediment Oxygen Demand SS Settleable Solids SSES Sanitary Sewer Evaluation Survey SSO Sanitary Sewer Overflow SWMM Storm Water Management Model TKN Total Kjeldahl Nitrogen TS Total Solids TSS Total Suspended Solids UAA Use Attainability Analysis URDP Upper River Des Peres Acronyms Page 2 February 2011 USFWS United States Fish and Wildlife Service USGS United States Geological Survey VSS Volatile Suspended Solids WBC-A Whole Body Contact – Class A WBC-B Whole Body Contact – Class B WBCR Whole Body Contact Recreation WQS Water Quality Standards WWTP Wastewater Treatment Plant Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX A Combined Sewer System Schematics This page is blank to facilitate double-sided printing. This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX B Hydraulic Model Results for Typical Year This page is blank to facilitate double-sided printing. Annual Total 002 41.0 0.00 to 6.0 53 59.0 003 205.3 0.01 to 24.1 62 218.4 004 304.6 0.02 to 44.5 52 275.5 005 58.4 0.00 to 7.3 64 69.5 006 41.5 0.02 to 8.0 26 105.8 007 31.2 0.01 to 5.5 30 63.2 008 35.7 0.00 to 7.0 32 99.9 009 18.4 0.00 to 3.6 34 36.4 010 54.7 0.00 to 9.4 31 59.0 011 8.4 0.00 to 1.7 33 23.6 012 14.0 0.00 to 3.7 17 52.0 013 1.0 0.00 to 0.4 14 11.0 014 842.3 0.00 to 149.3 42 842.8 015 1,000.1 0.36 to 117.2 46 513.8 016 1,006.6 0.54 to 197.2 31 1,502.2 017 4.7 0.00 to 1.0 31 9.1 018 1.3 0.00 to 0.4 12 7.7 019 17.3 0.03 to 2.9 27 18.9 020 3.2 0.00 to 0.7 15 15.5 021 0.1 0.00 to 0.1 3 1.6 022 0.1 0.00 to 0.1 4 2.1 023 0.0 0.00 to 0.0 0 0.0 024 0.3 0.00 to 0.1 21 1.5 025 2.1 0.00 to 0.4 34 5.1 026 0.4 0.00 to 0.1 28 0.7 027 3.0 0.01 to 1.4 9 38.6 028 1.6 0.00 to 0.3 20 6.2 029 0.1 0.00 to 0.0 16 0.8 030 1.9 0.00 to 0.4 24 2.9 031 0.3 0.00 to 0.1 10 3.3 032 1.6 0.00 to 0.3 21 7.6 033 0.0 0.00 to 0.0 0 0.0 034 12.0 0.00 to 2.0 39 26.8 035 10.5 0.00 to 1.7 43 22.1 036 20.7 0.00 to 4.0 29 52.2 037 352.4 0.00 to 78.9 51 634.7 038 184.6 0.00 to 48.7 27 488.1 041 19.7 0.00 to 3.4 46 44.8 042 0.5 0.00 to 0.1 14 3.3 043 16.5 0.01 to 4.3 20 85.7 044 49.5 0.00 to 6.6 60 64.9 045 1.0 0.01 to 0.5 9 13.1 046 39.7 0.01 to 7.5 33 87.0 047 972.3 0.08 to 238.5 36 1,513.1 BISSELL POINT SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range Page B-1 Annual Total BISSELL POINT SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range 048 30.2 0.01 to 4.7 45 48.9 049 806.9 0.00 to 205.7 40 1,023.2 050 57.6 0.00 to 11.7 35 53.1 051 129.9 0.02 to 30.5 29 179.3 052 16.7 0.10 to 9.5 5 51.7 053 0.0 0.00 to 0.0 2 0.4 055 0.8 0.00 to 0.2 15 3.1 057 13.2 0.00 to 1.4 65 13.1 059* 22.3 0.00 to 6.3 33 31.6 060 4.7 0.00 to 2.0 12 5.8 061 82.0 0.00 to 13.6 53 155.6 TOTAL** 6,522 Notes: * Volume for Outfall 059 is also included in Outfall 049 volume. ** Volume adjusted so as not to double count volume from Outfall 059. Page B-2 Annual Total 064 5.3 0.00 to 1.0 36 9.8 065 2.3 0.33 to 0.3 11 6.8 066 13.4 0.00 to 1.7 61 15.1 067 34.9 0.01 to 3.8 54 15.6 068 5.9 0.00 to 1.2 31 11.3 069 0.9 0.00 to 0.2 24 3.8 070 1.7 0.00 to 0.3 28 4.8 071 10.7 0.00 to 2.3 43 17.7 072 0.2 0.00 to 0.1 7 4.9 073 5.8 0.00 to 0.2 40 5.2 074 0.1 0.00 to 0.0 3 1.0 075 1.4 0.00 to 0.3 24 3.9 076 0.5 0.00 to 0.1 16 2.5 077 1.1 0.00 to 0.3 15 5.2 078 2.3 0.00 to 0.5 24 7.0 079 6.4 0.00 to 1.3 25 18.2 080 24.8 0.01 to 3.0 62 26.1 081 22.4 0.01 to 4.8 26 61.6 082 0.1 0.00 to 0.1 3 2.9 083 11.1 0.00 to 2.4 29 31.3 084 21.4 0.00 to 4.0 36 48.8 085 29.7 0.00 to 4.7 46 48.5 086 118.9 0.01 to 15.0 60 132.8 087 0.0 0.01 to 0.0 2 0.5 088 0.3 0.00 to 0.1 14 1.7 089 0.0 0.00 to 0.0 0 0.0 090 2.9 0.00 to 0.5 29 6.8 091 39.7 0.01 to 5.4 53 46.7 092 109.4 0.00 to 14.7 54 132.3 093 3.1 0.00 0.0 0.4 63 3.2 094 2.1 0.00 to 0.4 25 5.6 095 4.4 0.00 to 1.0 21 15.1 096 9.7 0.04 to 0.4 57 1.0 099 3.3 0.00 to 0.6 27 8.5 100 6.5 0.00 to 1.3 38 11.4 101 0.7 0.00 to 0.3 9 8.1 102 14.0 0.00 to 2.2 40 22.4 167 0.3 0.33 to 0.3 1 6.8 178 8.6 0.03 to 1.5 25 16.4 180 0.7 0.00 to 0.2 24 2.6 SUBTOTAL* 527 Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range LEMAY SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) CSOs Tributary to River Des Peres above Outfall 063* Page B-3 Annual Total Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range LEMAY SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) 008 0.9 0.13 to 0.8 2 14.6 009 0.0 0.01 to 0.0 2 1.8 010 313.7 0.16 to 67.8 28 580.4 011 0.6 0.62 to 0.6 1 12.8 012 1.1 0.37 to 0.7 2 11.0 013 39.2 0.16 to 5.8 26 47.0 014 2.9 0.12 to 0.9 6 12.8 015 976.6 0.62 to 109.1 55 928.7 016 0.3 0.27 to 0.3 1 4.8 017 5.7 0.20 to 1.4 10 16.5 018 0.5 0.16 to 0.3 2 5.0 019 0.2 0.01 to 0.1 5 4.1 020 5.1 0.48 to 1.5 5 21.5 021 15.7 0.38 to 3.2 15 32.7 022 8.6 0.30 to 2.2 10 23.9 023 388.9 1.75 to 68.8 23 565.4 024 0.0 0.02 to 0.0 1 0.6 025 4.7 0.18 to 1.2 9 17.4 026 28.9 0.38 to 4.4 20 126.7 027 6.2 0.37 to 2.0 6 25.5 028 1.2 0.43 to 0.8 2 12.1 029 25.3 0.58 to 5.0 14 57.5 030 0.2 0.00 to 0.1 3 3.9 031 6.3 0.09 to 1.0 20 11.3 032 0.0 0.00 to 0.0 0 0.0 036 0.4 0.38 to 0.4 1 5.3 037 21.9 0.11 to 3.3 22 34.4 039 16.2 0.14 to 3.7 13 39.3 041 1.2 0.00 to 0.9 4 7.2 042 30.8 0.82 to 6.1 14 66.4 043 42.9 0.58 to 7.4 21 72.4 044 0.0 0.00 to 0.0 0 0.0 046 0.2 0.00 to 0.1 13 1.5 048 1.5 0.00 to 0.5 10 12.5 049 0.3 0.00 to 0.1 14 1.7 050 93.2 0.16 to 13.5 32 121.1 052 31.1 0.63 to 6.4 13 75.4 053 17.9 0.00 to 4.4 21 64.3 054 6.5 0.00 to 2.0 16 30.0 057 49.7 0.30 to 9.4 20 82.4 058 24.1 0.01 to 6.1 19 82.4 060 0.0 0.00 to 0.0 0 0.0 061 0.7 0.24 to 0.4 2 7.2 All Other River Des Peres Service Area CSOs Page B-4 Annual Total Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range LEMAY SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) 062 0.4 0.00 to 0.1 13 2.7 063 3,507.7 0.70 to 526.2 43 4,027.7 103 31.2 0.04 to 8.0 25 61.7 104 53.9 0.02 to 9.0 39 45.6 105 16.5 0.00 to 3.0 34 89.3 106 77.4 0.01 to 10.5 53 91.0 107 17.8 0.02 to 1.3 52 2.5 108 13.0 0.00 to 1.5 57 13.7 110 0.5 0.00 to 0.1 14 2.8 111 17.6 0.00 to 4.9 19 49.3 112 1.7 0.00 to 0.6 19 15.1 113 0.1 0.00 to 0.0 13 0.7 114 0.3 0.00 to 0.1 14 1.8 115 0.0 0.01 to 0.0 1 0.3 116 0.5 0.00 to 0.1 13 3.1 117 2.4 0.02 to 0.9 9 21.8 118 0.0 0.00 to 0.0 0 0.0 119 22.5 0.00 to 2.0 60 10.0 120 4.6 0.00 to 0.7 29 4.4 121 17.2 0.00 to 3.7 26 47.5 122 4.0 0.01 to 0.9 21 8.7 123 3.4 0.00 to 0.7 22 6.5 124 13.3 0.00 to 3.4 21 47.3 125 1.2 0.00 to 0.3 20 5.9 126 0.0 0.00 to 0.0 0 0.0 127 0.0 0.00 to 0.0 0 0.0 128 15.7 0.00 to 2.7 38 28.5 130 2.7 0.00 to 0.4 40 4.8 131 0.3 0.00 to 0.1 12 2.8 134 0.0 0.00 to 0.0 0 0.0 135 1.3 0.00 to 0.3 25 3.4 136 6.2 0.00 to 1.5 20 20.9 137 10.8 0.00 to 1.1 53 5.8 138 10.5 0.00 to 0.9 54 3.7 139 0.0 0.00 to 0.0 0 0.0 140 3.4 0.00 to 0.8 28 5.0 141 0.5 0.00 to 0.3 4 3.8 142 50.4 0.00 to 8.0 41 81.6 143 27.4 0.00 to 4.2 48 44.8 144 27.0 0.00 to 4.5 44 37.5 147 432.4 0.01 to 71.9 30 173.2 149 0.0 0.00 to 0.0 0 0.0 151 11.2 0.00 to 2.1 31 23.8 152 12.1 0.00 to 2.2 35 17.1 Page B-5 Annual Total Outfall No. Volume (million gallons)Events per Year Peak Flow (MGD)Event Range LEMAY SERVICE AREA ESTIMATED OVERFLOW QUANTITIES AVERAGE YEAR PRECIPITATION (Year 2000) 153 15.6 0.00 to 2.6 38 28.4 154 6.1 0.00 to 0.9 57 7.4 157 0.0 0.00 to 0.0 0 0.0 160 1.9 0.04 to 0.4 14 4.8 161 34.5 0.01 to 6.1 33 65.1 163 13.4 0.00 to 1.7 60 15.2 164 3.3 0.00 to 0.3 52 1.1 165 3.1 0.00 to 0.3 51 1.2 166 11.5 0.00 to 2.0 37 17.9 168 0.0 0.00 to 0.0 0 0.0 170 1.0 0.01 to 0.7 3 14.7 171 0.0 0.00 to 0.0 0 0.0 172 0.0 0.00 to 0.0 0 0.0 173 0.0 0.00 to 0.0 0 0.0 174 0.0 0.00 to 0.0 0 0.0 175 15.1 0.00 to 3.0 29 38.5 176 35.2 0.00 to 4.0 54 15.7 177 0.0 0.00 to 0.0 2 0.1 179 0.0 0.00 to 0.0 0 0.0 181 0.0 0.00 to 0.00 0 0.0 TOTAL** 6,731 Notes: * Volumes for outfalls above Outfall 063 are also included in Outfall 063 volume. ** Volume adjusted so as not to double count volumes from CSOs located above Outfall 063. Page B-6 Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX C Updated Comparisons of Data to Water Quality Criteria This page is blank to facilitate double-sided printing. Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 05587455 10/23/1996 13:40 W S No 9.9 5 198% Mississippi 05587455 11/27/1996 14:20 W S No 13.7 5 274% Mississippi 05587455 12/3/1996 10:15 D B No 13.6 5 272% Mississippi 05587455 1/7/1997 10:40 D B No 14 5 280% Mississippi 05587455 2/26/1997 12:55 W S No 12.1 5 242% Mississippi 05587455 3/11/1997 11:05 W S No 9.2 5 184% Mississippi 05587455 4/3/1997 13:30 D B No 12.4 5 248% Mississippi 05587455 4/23/1997 14:10 D B No 10.8 5 216% Mississippi 05587455 5/6/1997 10:40 D B No 9.3 5 186% Mississippi 05587455 6/2/1997 14:55 D B No 8.7 5 174% Mississippi 05587455 6/27/1997 12:45 D B No 7.4 5 148% Mississippi 05587455 7/8/1997 11:00 D S No 7.3 5 146% Mississippi 05587455 8/5/1997 11:15 D B No 10.8 5 216% Mississippi 05587455 9/11/1997 11:35 D B No 7.3 5 146% Mississippi 05587455 10/16/1997 11:25 D B No 9.2 5 184% Mississippi 05587455 11/12/1997 13:35 D B No 12.3 5 246% Mississippi 05587455 12/4/1997 10:45 W S No 9.2 5 184% Mississippi 05587455 1/22/1998 10:20 W B No 14 5 280% Mississippi 05587455 2/17/1998 12:25 W S No 13.7 5 274% Mississippi 05587455 3/17/1998 10:15 W S No 13 5 260% Mississippi 05587455 3/23/1998 13:15 D B No 13.3 5 266% Mississippi 05587455 4/14/1998 11:10 W S No 10.4 5 208% Mississippi 05587455 5/5/1998 10:10 D B No 9.7 5 194% Mississippi 05587455 5/19/1998 9:35 D B No 7.4 5 148% Mississippi 05587455 6/2/1998 9:45 D B No 7.3 5 146% Mississippi 05587455 6/15/1998 12:50 W S No 6.9 5 138% Mississippi 05587455 7/6/1998 13:40 W S No 5.7 5 114% Mississippi 05587455 8/12/1998 10:55 D S No 7.4 5 148% Mississippi 05587455 9/1/1998 10:45 W S No 6.7 5 134% Mississippi 05587455 10/14/1998 12:15 D B No 9.1 5 182% Mississippi 05587455 11/23/1998 13:05 D B No 12.7 5 254% Mississippi 05587455 12/8/1998 10:35 W S No 13.3 5 266% Mississippi 05587455 2/2/1999 10:30 W S No 15.2 5 304% Mississippi 05587455 2/25/1999 13:05 D B No 14.3 5 286% Mississippi 05587455 3/17/1999 13:35 D B No 7.1 5 142% Mississippi 05587455 4/12/1999 13:20 D B No 9.1 5 182% Mississippi 05587455 4/20/1999 10:45 D B No 10 5 200% Mississippi 05587455 5/10/1999 13:50 D B No 9.3 5 186% Mississippi 05587455 5/24/1999 13:55 D B No 8.1 5 162% Mississippi 05587455 6/7/1999 14:10 D B No 9 5 180% Mississippi 05587455 6/21/1999 14:05 W B No 9.7 5 194% Mississippi 05587455 7/24/1999 14:20 D B No 7.9 5 158% Mississippi 05587455 8/9/1999 13:40 W S No 7.7 5 154% Mississippi 05587455 9/13/1999 13:30 W S No 8.8 5 176% Mississippi 05587455 10/19/1999 15:05 D B No 11.2 5 224% Mississippi 05587455 11/22/1999 13:15 D B No 11.8 5 236% Mississippi 05587455 12/7/1999 13:35 W B No 12.5 5 250% Mississippi 05587455 1/19/2000 12:25 W S No 15.7 5 314% Mississippi 05587455 2/14/2000 13:55 D B No 16.9 5 338% Mississippi 05587455 3/13/2000 13:05 W S No 10.8 5 216% Mississippi 05587455 4/3/2000 14:00 D B No 12.3 5 246% Mississippi 05587455 5/4/2000 10:35 D B No 7.6 5 152% Mississippi 05587455 6/9/2000 19:05 D B No 7.8 5 156% Mississippi 05587455 6/26/2000 14:10 W S No 6.6 5 132% Mississippi 05587455 7/10/2000 13:50 D B No 5.8 5 116% Mississippi 05587455 8/11/2000 19:25 D S No 15.1 5 302% Mississippi 05587455 9/11/2000 13:55 W S No 8.2 5 164% Mississippi 05587455 10/2/2000 14:10 D B No 8.1 5 162% Mississippi 05587455 11/7/2000 10:50 W S No 7.5 5 150% Mississippi 05587455 2/6/2001 11:05 D B No 14.7 5 294% Mississippi 05587455 2/21/2001 13:15 W B No 13.4 5 268% Mississippi 05587455 3/1/2001 11:25 W S No 13.6 5 272% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 05587455 3/7/2001 13:10 D B No 12.6 5 252% Mississippi 05587455 3/21/2001 12:40 D B No 13.2 5 264% Mississippi 05587455 4/2/2001 13:45 W B No 14.2 5 284% Mississippi 05587455 4/16/2001 14:35 W S No 8.7 5 174% Mississippi 05587455 4/30/2001 14:10 W B No 9 5 180% Mississippi 05587455 5/14/2001 14:45 D B No 7.8 5 156% Mississippi 05587455 6/6/2001 13:30 W S No 7.4 5 148% Mississippi 05587455 6/11/2001 13:25 D B No 6.8 5 136% Mississippi 05587455 7/16/2001 14:20 D B No 8.8 5 176% Mississippi 05587455 8/6/2001 14:25 D B No 9.6 5 192% Mississippi 05587455 9/12/2001 12:45 D B No 11.2 5 224% Mississippi 05587455 10/15/2001 14:20 W S No 10.7 5 214% Mississippi 05587455 11/19/2001 13:25 W S No 12.8 5 256% Mississippi 05587455 12/3/2001 13:25 D B No 11.1 5 222% Mississippi 05587455 1/16/2002 13:10 D B No 18.5 5 370% Mississippi 05587455 2/11/2002 14:15 D B No 15.9 5 318% Mississippi 05587455 3/12/2002 13:45 D B No 13.7 5 274% Mississippi 05587455 4/1/2002 14:05 D B No 14.4 5 288% Mississippi 05587455 5/6/2002 14:05 W S No 9 5 180% Mississippi 05587455 6/3/2002 13:55 D B No 8.1 5 162% Mississippi 05587455 7/8/2002 14:10 D B No 5.9 5 118% Mississippi 05587455 8/12/2002 14:25 D B No 9.6 5 192% Mississippi 05587455 9/9/2002 14:15 D B No 9.1 5 182% Mississippi 05587455 10/21/2002 13:20 D S No 9.7 5 194% Mississippi 05587455 11/6/2002 14:00 W S No 11.5 5 230% Mississippi 05587455 12/2/2002 13:45 D B No 14.2 5 284% Mississippi 05587455 2/19/2003 12:55 W S No 16.6 5 332% Mississippi 05587455 3/4/2003 10:25 D B No 20.1 5 402% Mississippi 05587455 3/18/2003 10:45 W B No 16.6 5 332% Mississippi 05587455 4/21/2003 14:05 W S No 8.6 5 172% Mississippi 05587455 5/5/2003 13:45 W S No 9.8 5 196% Mississippi 05587455 6/2/2003 13:00 W S No 7.1 5 142% Mississippi 05587455 7/7/2003 13:35 D B No 10.2 5 204% Mississippi 05587455 8/4/2003 13:45 W S No 11.2 5 224% Mississippi 05587455 9/8/2003 14:05 D B No 7.9 5 158% Mississippi 05587455 10/22/2003 13:10 D B No 10.6 5 212% Mississippi 05587455 11/12/2003 12:25 D B No 11.8 5 236% Mississippi 05587455 12/1/2003 13:45 D B No 11.1 5 222% Mississippi 05587455 1/12/2004 14:45 D B No 15.4 5 308% Mississippi 05587455 2/23/2004 13:40 W B No 18.1 5 362% Mississippi 05587455 3/8/2004 14:45 D B No 9.7 5 194% Mississippi 05587455 4/14/2004 13:00 D B No 9.2 5 184% Mississippi 05587455 5/10/2004 13:10 W B No 9.9 5 198% Mississippi 05587455 6/14/2004 13:15 D B No 6.7 5 134% Mississippi 05587455 7/12/2004 13:25 D B No 7 5 140% Mississippi 05587455 8/9/2004 13:15 D B No 6.8 5 136% Mississippi 05587455 9/20/2004 13:45 D B No 8.3 5 166% Mississippi 05587455 10/25/2004 12:30 D B No 11.2 5 224% Mississippi 05587455 11/8/2004 13:00 D B No 11.1 5 222% Mississippi 05587455 12/6/2004 13:35 W S No 11.3 5 226% Mississippi 05587455 1/10/2005 13:30 D B No 8.1 5 162% Mississippi 05587455 2/8/2005 13:15 W S No 14 5 280% Mississippi 05587455 3/7/2005 13:35 W S No 15.4 5 308% Mississippi 05587455 4/12/2005 9:45 W S No 8.8 5 176% Mississippi 05587455 4/21/2005 15:15 W S No 8.3 5 166% Mississippi 05587455 5/9/2005 12:40 W B No 10.9 5 218% Mississippi 05587455 6/10/2005 11:55 W S No 7.8 5 156% Mississippi 05587455 6/20/2005 14:00 D B No 7.8 5 156% Mississippi 05587455 7/11/2005 12:15 W S No 6.4 5 128% Mississippi 05587455 7/20/2005 12:30 W B No 9.6 5 192% Mississippi 05587455 8/8/2005 12:50 D B No 9.9 5 198% Mississippi 05587455 9/12/2005 12:40 D B No 9.1 5 182% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 05587455 10/3/2005 14:10 D B No 10 5 200% Mississippi 05587455 11/7/2005 13:30 W S No 10.1 5 202% Mississippi 05587455 12/12/2005 12:45 D B No 16.2 5 324% Mississippi 05587455 1/9/2006 13:55 W B No 13.4 5 268% Mississippi 05587455 2/8/2006 13:15 W S No 16.6 5 332% Mississippi 05587455 3/13/2006 13:20 W S No 14.4 5 288% Mississippi 05587455 4/11/2006 10:35 D B No 14.7 5 294% Mississippi 05587455 5/2/2006 16:10 W S No 8.4 5 168% Mississippi 05587455 6/2/2006 18:15 W S No 7.1 5 142% Mississippi 05587455 6/12/2006 15:45 W S No 7.2 5 144% Mississippi 05587455 7/25/2006 10:30 D B No 9.8 5 196% Mississippi 05587455 8/23/2006 10:25 W S No 8.2 5 164% Mississippi 05587455 9/20/2006 12:00 D B No 6.7 5 134% Mississippi 05587455 10/18/2006 10:25 W S No 12.3 5 246% Mississippi 05587455 10/24/2006 9:00 D B No 7.7 5 154% Mississippi 05587455 11/27/2006 14:25 D B No 16.4 5 328% Mississippi 05587455 12/11/2006 15:15 D S No 14.4 5 288% Mississippi 05587455 1/10/2007 13:05 D B No 13.8 5 276% Mississippi 05587455 2/28/2007 14:05 W S No 12.4 5 248% Mississippi 05587455 3/26/2007 13:20 D B No 10.3 5 206% Mississippi 05587455 4/12/2007 9:45 W S No 11.8 5 236% Mississippi 05587455 4/24/2007 9:40 W S No 10.4 5 208% Mississippi 05587455 5/30/2007 8:53 W B No 8.3 5 166% Mississippi 05587455 6/26/2007 10:10 D S No 5.5 5 110% Mississippi 05587455 7/17/2007 9:50 W B No 9.8 5 196% Mississippi 05587455 8/22/2007 10:35 D B No 5.4 5 108% Mississippi 05587455 9/7/2007 10:15 W S No 6 5 120% Mississippi 05587455 10/22/2007 12:35 W No 8.8 5 176% Mississippi 05587455 11/28/2007 13:00 W No 12.7 5 254% Mississippi 05587455 12/19/2007 13:05 D B No 17 5 340% Mississippi 05587455 1/9/2008 13:25 W No 12.8 5 256% Mississippi 05587455 5/20/2008 15:10 D No 8.56 5 171% Mississippi 05587455 5/28/2008 12:35 W No 8.43 5 169% Mississippi 05587455 7/15/2008 12:10 D No 5.51 5 110% Mississippi 05587455 7/29/2008 16:20 W No 6.08 5 122% Mississippi 05587455 9/11/2008 11:32 W No 7.46 5 149% Mississippi 05587455 9/24/2008 12:35 D No 4.46 5 89% Mississippi 05587455 10/1/2008 11:40 W No 5.87 5 117% Mississippi 05587455 10/8/2008 11:44 D No 7.16 5 143% Mississippi 05587455 10/16/2008 11:23 W No 8 5 160% Mississippi 05587455 10/21/2008 10:55 D No 8.79 5 176% Mississippi 05587455 10/28/2008 11:37 D No 10.08 5 202% Mississippi 07005500 10/26/2004 10:10 W S No 11.1 5 222% Mississippi 07005500 4/12/2005 14:25 W S No 9 5 180% Mississippi 07005500 4/22/2005 9:50 W S No 8.1 5 162% Mississippi 07005500 5/10/2005 9:30 D B No 10.2 5 204% Mississippi 07005500 6/10/2005 15:25 W S No 5.4 5 108% Mississippi 07005500 6/21/2005 10:05 D B No 6.5 5 130% Mississippi 07005500 7/12/2005 9:50 W S No 6.7 5 134% Mississippi 07005500 7/20/2005 15:40 W B No 9.6 5 192% Mississippi 07005500 8/9/2005 10:15 D B No 7.3 5 146% Mississippi 07005500 10/4/2005 10:10 D B No 9 5 180% Mississippi 07005500 4/10/2006 12:35 D B No 12.3 5 246% Mississippi 07005500 5/1/2006 13:10 W S No 9.2 5 184% Mississippi 07005500 5/2/2006 9:50 W S No 8.1 5 162% Mississippi 07005500 6/2/2006 11:40 W S No 7.9 5 158% Mississippi 07005500 6/5/2006 12:40 D B No 7.4 5 148% Mississippi 07005500 6/12/2006 9:50 W S No 6.7 5 134% Mississippi 07005500 7/24/2006 13:15 D B No 8.9 5 178% Mississippi 07005500 8/22/2006 12:20 W B No 7 5 140% Mississippi 07005500 10/17/2006 10:50 W S No 10.2 5 204% Mississippi 07005500 4/11/2007 11:40 W S No 11.1 5 222% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 07005500 4/23/2007 14:10 D B No 9.1 5 182% Mississippi 07005500 5/29/2007 14:15 W S No 6.2 5 124% Mississippi 07005500 6/25/2007 15:05 W S No 7.4 5 148% Mississippi 07005500 7/16/2007 14:25 D B No 8.6 5 172% Mississippi 07005500 8/21/2007 13:40 W B No 6.5 5 130% Mississippi 07005500 9/7/2007 16:10 W S No 6.3 5 126% Mississippi 07005500 5/21/2008 10:05 D No 7.79 5 156% Mississippi 07005500 5/28/2008 14:45 W No 7.28 5 146% Mississippi 07005500 7/15/2008 19:15 D No 6.38 5 128% Mississippi 07005500 7/31/2008 8:30 W No 5.08 5 102% Mississippi 07005500 9/11/2008 16:38 W No 7.78 5 156% Mississippi 07005500 9/24/2008 9:30 D No 4.89 5 98% Mississippi 07005500 10/1/2008 9:53 W No 7.69 5 154% Mississippi 07005500 10/8/2008 9:16 D No 8.43 5 169% Mississippi 07005500 10/16/2008 9:03 W No 8.31 5 166% Mississippi 07005500 10/21/2008 8:42 D No 8.74 5 175% Mississippi 07005500 10/28/2008 9:31 D No 9.18 5 184% Mississippi 07010000 10/26/2004 9:15 W S No 10.8 5 216% Mississippi 07010000 4/12/2005 13:35 W S No 11.3 5 226% Mississippi 07010000 4/22/2005 9:10 W S No 8.1 5 162% Mississippi 07010000 5/10/2005 8:55 D B No 10.1 5 202% Mississippi 07010000 6/10/2005 14:40 W S No 6.1 5 122% Mississippi 07010000 6/21/2005 9:20 D B No 6.4 5 128% Mississippi 07010000 7/12/2005 9:10 W S No 6.6 5 132% Mississippi 07010000 7/20/2005 15:10 W B No 9.4 5 188% Mississippi 07010000 8/9/2005 9:30 D B No 7 5 140% Mississippi 07010000 8/9/2005 9:31 D B No 7 5 140% Mississippi 07010000 10/4/2005 9:20 D B No 8.7 5 174% Mississippi 07010000 4/10/2006 11:55 D B No 12.8 5 256% Mississippi 07010000 5/1/2006 11:35 W S No 9.5 5 190% Mississippi 07010000 5/2/2006 9:10 W S No 8.2 5 164% Mississippi 07010000 6/2/2006 11:10 W S No 7.6 5 152% Mississippi 07010000 6/5/2006 12:00 D B No 7.4 5 148% Mississippi 07010000 6/12/2006 9:10 W S No 6.7 5 134% Mississippi 07010000 7/24/2006 13:58 D B No 8.9 5 178% Mississippi 07010000 8/22/2006 13:05 W B No 7 5 140% Mississippi 07010000 10/17/2006 11:50 W S No 10.1 5 202% Mississippi 07010000 10/23/2006 13:55 D B No 9.6 5 192% Mississippi 07010000 4/11/2007 11:00 W S No 11.2 5 224% Mississippi 07010000 4/23/2007 13:30 D B No 9.1 5 182% Mississippi 07010000 5/29/2007 13:37 W S No 6.8 5 136% Mississippi 07010000 6/25/2007 13:25 W S No 7.4 5 148% Mississippi 07010000 7/16/2007 13:50 D B No 8.2 5 164% Mississippi 07010000 8/21/2007 13:00 W B No 6.4 5 128% Mississippi 07010000 9/7/2007 13:25 W S No 6.3 5 126% Mississippi 07010000 5/21/2008 11:00 D No 8.04 5 161% Mississippi 07010000 5/28/2008 15:55 W No 7.3 5 146% Mississippi 07010000 7/15/2008 19:40 D No 6.12 5 122% Mississippi 07010000 7/31/2008 10:00 W No 5.56 5 111% Mississippi 07010000 9/11/2008 17:16 W No 7.74 5 155% Mississippi 07010000 9/24/2008 10:00 D No 4.83 5 97% Mississippi 07010000 10/1/2008 9:22 W No 7.52 5 150% Mississippi 07010000 10/8/2008 9:38 D No 8.08 5 162% Mississippi 07010000 10/16/2008 9:23 W No 8.48 5 170% Mississippi 07010000 10/21/2008 9:09 D No 8.52 5 170% Mississippi 07010000 10/28/2008 9:51 D No 8.9 5 178% Mississippi 07010220 10/26/2004 12:30 W S No 10.9 5 218% Mississippi 07010220 4/12/2005 16:20 W S No 8.7 5 174% Mississippi 07010220 4/22/2005 11:05 W S No 7.8 5 156% Mississippi 07010220 5/10/2005 10:50 D B No 9.6 5 192% Mississippi 07010220 6/10/2005 16:30 W S No 5.1 5 102% Mississippi 07010220 6/21/2005 11:15 D B No 6.3 5 126% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 07010220 7/12/2005 11:00 W S No 6.3 5 126% Mississippi 07010220 7/20/2005 16:50 W B No 8.9 5 178% Mississippi 07010220 8/9/2005 11:25 D B No 6.8 5 136% Mississippi 07010220 10/4/2005 11:35 D B No 8.6 5 172% Mississippi 07010220 4/10/2006 13:50 D B No 11.7 5 234% Mississippi 07010220 5/1/2006 14:10 W S No 8.9 5 178% Mississippi 07010220 5/2/2006 11:05 W S No 8.2 5 164% Mississippi 07010220 6/2/2006 13:00 W S No 7.6 5 152% Mississippi 07010220 6/5/2006 13:50 D B No 7.4 5 148% Mississippi 07010220 6/12/2006 11:05 W S No 6.5 5 130% Mississippi 07010220 7/24/2006 15:00 D B No 8.9 5 178% Mississippi 07010220 8/22/2006 14:08 W B No 6.5 5 130% Mississippi 07010220 10/17/2006 12:50 W S No 9.9 5 198% Mississippi 07010220 10/23/2006 15:05 D B No 9.5 5 190% Mississippi 07010220 4/11/2007 13:05 W S No 9.9 5 198% Mississippi 07010220 4/23/2007 12:35 D B No 10.4 5 208% Mississippi 07010220 5/29/2007 11:57 W S No 6.7 5 134% Mississippi 07010220 6/25/2007 12:35 W S No 7.4 5 148% Mississippi 07010220 7/16/2007 12:05 D B No 7.7 5 154% Mississippi 07010220 8/21/2007 11:30 W B No 6.2 5 124% Mississippi 07010220 9/7/2007 14:10 W S No 6.3 5 126% Mississippi 07010220 5/21/2008 12:25 D No 7.84 5 157% Mississippi 07010220 5/28/2008 17:00 W No 7.58 5 152% Mississippi 07010220 7/15/2008 18:00 D No 6.03 5 121% Mississippi 07010220 7/31/2008 12:00 W No 5.4 5 108% Mississippi 07010220 9/11/2008 15:35 W No 7.67 5 153% Mississippi 07010220 9/24/2008 8:30 D No 4.96 5 99% Mississippi 07010220 10/1/2008 8:20 W No 7.22 5 144% Mississippi 07010220 10/8/2008 8:17 D No 8.04 5 161% Mississippi 07010220 10/16/2008 8:09 W No 8.11 5 162% Mississippi 07010220 10/21/2008 7:48 D No 8.39 5 168% Mississippi 07010220 10/28/2008 8:14 D No 8.82 5 176% Mississippi 07019370 10/26/2004 11:50 W S No 10.7 5 214% Mississippi 07019370 4/12/2005 15:50 W S No 8.9 5 178% Mississippi 07019370 4/22/2005 11:45 W S No 7.7 5 154% Mississippi 07019370 5/10/2005 11:15 D B No 9.7 5 194% Mississippi 07019370 6/10/2005 17:00 W S No 5.4 5 108% Mississippi 07019370 6/21/2005 12:00 D B No 6.4 5 128% Mississippi 07019370 7/12/2005 11:30 W S No 6.3 5 126% Mississippi 07019370 7/20/2005 17:10 W B No 8.9 5 178% Mississippi 07019370 8/9/2005 11:50 D B No 6.8 5 136% Mississippi 07019370 10/4/2005 12:15 D B No 8.6 5 172% Mississippi 07019370 4/10/2006 14:20 D B No 12.6 5 252% Mississippi 07019370 5/1/2006 14:45 W S No 9.1 5 182% Mississippi 07019370 5/2/2006 11:35 W S No 8 5 160% Mississippi 07019370 6/2/2006 13:35 W S No 7.7 5 154% Mississippi 07019370 6/5/2006 14:15 D B No 7.4 5 148% Mississippi 07019370 6/12/2006 11:25 W S No 6.6 5 132% Mississippi 07019370 7/24/2006 15:32 D B No 8.7 5 174% Mississippi 07019370 8/22/2006 14:35 W B No 6.5 5 130% Mississippi 07019370 10/17/2006 13:13 W S No 9.7 5 194% Mississippi 07019370 10/23/2006 15:45 D B No 9.4 5 188% Mississippi 07019370 4/11/2007 13:35 W S No 11.2 5 224% Mississippi 07019370 4/23/2007 11:55 D B No 10.3 5 206% Mississippi 07019370 5/29/2007 12:28 W S No 6.8 5 136% Mississippi 07019370 6/25/2007 12:10 W S No 7.5 5 150% Mississippi 07019370 7/16/2007 12:30 D B No 7.8 5 156% Mississippi 07019370 8/21/2007 12:00 W B No 6.1 5 122% Mississippi 07019370 9/7/2007 14:35 W S No 6.3 5 126% Mississippi 07019370 5/21/2008 13:15 D No 7.95 5 159% Mississippi 07019370 5/28/2008 18:45 W No 7.36 5 147% Mississippi 07019370 7/15/2008 17:15 D No 5.88 5 118% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Mississippi 07019370 7/31/2008 13:50 W No 5.4 5 108% Mississippi 07019370 9/11/2008 15:03 W No 7.57 5 151% Mississippi 07019370 9/24/2008 7:50 D No 5.45 5 109% Mississippi 07019370 10/1/2008 7:44 W No 7.11 5 142% Mississippi 07019370 10/8/2008 7:41 D No 7.96 5 159% Mississippi 07019370 10/16/2008 7:28 W No 8.22 5 164% Mississippi 07019370 10/21/2008 7:17 D No 8.42 5 168% Mississippi 07019370 10/28/2008 7:40 D No 9.15 5 183% Maline Ck 07005000 8/1/1996 9:45 D B No 6.5 5 130% Maline Ck 07005000 9/23/1996 15:30 W S No 4.9 5 98% Maline Ck 07005000 12/11/1996 11:30 D B No 10 5 200% Maline Ck 07005000 3/5/1997 13:15 D B No 11 5 220% Maline Ck 07005000 5/25/1997 23:50 W S No 4 5 80% Maline Ck 07005000 6/10/1997 9:15 D B No 6.9 5 138% Maline Ck 07005000 8/26/1997 8:30 W B No 6.2 5 124% Maline Ck 07005000 9/2/1997 16:34 W S No 6.4 5 128% Maline Ck 07005000 12/15/1997 14:50 D B No 12.7 5 254% Maline Ck 07005000 2/24/1998 10:45 D B No 14.4 5 288% Maline Ck 07005000 4/15/1998 6:55 W S Yes 6.5 5 130% Maline Ck 07005000 6/23/1998 8:15 W S Yes 4.3 5 86% Maline Ck 07005000 12/1/1998 10:35 D S No 8.4 5 168% Maline Ck 07005000 2/10/1999 13:55 D B No 9.6 5 192% Maline Ck 07005000 2/11/1999 16:30 W S No 9.9 5 198% Maline Ck 07005000 5/4/1999 23:22 W S Yes 6.1 5 122% Maline Ck 07005000 6/17/1999 12:35 D B No 4.9 5 98% Maline Ck 07005000 8/3/1999 9:40 D B No 5.6 5 112% Maline Ck 07005000 12/9/1999 15:43 W S No 8.5 5 170% Maline Ck 07005000 1/6/2000 10:05 D B No 12.7 5 254% Maline Ck 07005000 2/29/2000 9:58 D B No 8.5 5 170% Maline Ck 07005000 4/7/2000 3:38 W S No 9.3 5 186% Maline Ck 07005000 6/15/2000 10:15 D B No 4.8 5 96% Maline Ck 07005000 8/1/2000 12:00 D S No 6.1 5 122% Maline Ck 07005000 12/18/2000 17:10 W B No 11.2 5 224% Maline Ck 07005000 2/9/2001 10:54 W S No 8.8 5 176% Maline Ck 07005000 2/27/2001 15:55 W S No 10.7 5 214% Maline Ck 07005000 4/10/2001 23:31 W S No 5 5 100% Maline Ck 07005000 5/29/2001 15:40 W B No 14.4 5 288% Maline Ck 07005000 8/27/2001 13:45 D B No 4.6 5 92% Maline Ck 07005000 10/24/2001 0:45 W S No 6 5 120% Maline Ck 07005000 12/10/2001 17:00 D B No 6.9 5 138% Maline Ck 07005000 2/5/2002 9:00 D B No 11.2 5 224% Maline Ck 07005000 3/9/2002 3:32 W S No 10.3 5 206% Maline Ck 07005000 5/30/2002 8:15 W S No 5.8 5 116% Maline Ck 07005000 8/8/2002 11:30 W S No 2.9 5 58% Maline Ck 07005000 10/29/2002 5:16 W S No 8.6 5 172% Maline Ck 07005000 12/17/2002 9:35 W B No 7 5 140% Maline Ck 07005000 2/4/2003 10:15 D B No 11 5 220% Maline Ck 07005000 4/16/2003 21:09 W S No 8.3 5 166% Maline Ck 07005000 6/9/2003 14:25 D B No 10.5 5 210% Maline Ck 07005000 8/12/2003 9:40 D B No 5.8 5 116% Maline Ck 07005000 10/9/2003 14:42 W S No 7.2 5 144% Maline Ck 07005000 12/4/2003 9:30 W S No 10.6 5 212% Maline Ck 07005000 2/9/2004 14:30 D S No 15.5 5 310% Maline Ck 07005000 3/4/2004 12:38 W S No 14.6 5 292% Maline Ck 07005000 5/17/2004 14:15 D B No 6.7 5 134% Maline Ck 07005000 8/4/2004 10:00 W S No 6.1 5 122% Maline Ck 07005000 10/5/2004 12:00 D B No 3.1 5 62% Maline Ck 07005000 10/26/2004 17:00 W S No 7.8 5 156% Maline Ck 07005000 3/22/2005 13:22 W S No 12.1 5 242% Maline Ck 07005000 4/25/2005 14:30 W S No 7 5 140% Maline Ck 07005000 6/20/2005 13:50 D B No 10.2 5 204% Maline Ck 07005000 8/8/2005 12:13 D B No 7 5 140% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Maline Ck 07005000 10/3/2005 13:30 D B No 6.4 5 128% Maline Ck 07005000 10/31/2005 16:03 W S No 8.4 5 168% Maline Ck 07005000 4/4/2006 10:15 W S No 10.3 5 206% Maline Ck 07005000 5/1/2006 22:18 W S No 6.8 5 136% Maline Ck 07005000 6/6/2006 10:58 W B No 4.8 5 96% Maline Ck 07005000 8/21/2006 16:15 D B No 8.6 5 172% Maline Ck 07005000 10/2/2006 12:45 D B No 7.8 5 156% Maline Ck 07005000 10/16/2006 15:27 W S No 8.5 5 170% Maline Ck 07005000 1/16/2007 14:10 W S No 14.3 5 286% Maline Ck 07005000 2/5/2007 13:55 W S No 14.5 5 290% Maline Ck 07005000 3/19/2007 14:25 D B No 15.9 5 318% Maline Ck 07005000 4/3/2007 13:37 W S No 9.1 5 182% Maline Ck 07005000 4/10/2007 10:50 W S No 13.2 5 264% Maline Ck 07005000 5/21/2007 10:45 D B No 6.2 5 124% Maline Ck 07005000 6/18/2007 10:08 W S No 2.6 5 52% Maline Ck 07005000 7/23/2007 15:30 D B No 6.7 5 134% Maline Ck 07005000 8/8/2007 16:45 D B No 5 5 100% Maline Ck 07005000 9/12/2007 15:25 D B No 5.2 5 104% Maline Ck 07005000 1/29/2008 11:55 D No 11.31 5 226% Maline Ck 07005000 2/27/2008 7:01 D No 9.76 5 195% Maline Ck 07005000 3/11/2008 7:19 D No 9.45 5 189% Maline Ck 07005000 4/8/2008 7:05 W No 10.42 5 208% Maline Ck 07005000 5/19/2008 6:55 D No 10.17 5 203% Maline Ck 07005000 6/3/2008 12:00 W No 7.5 5 150% Maline Ck 07005000 7/15/2008 6:55 D No 6.28 5 126% Maline Ck 07005000 8/14/2008 7:00 D No 6.43 5 129% Maline Ck 07005000 8/28/2008 6:50 W No 5.9 5 118% Maline Ck 07005000 9/4/2008 6:07 W No 7.18 5 144% Maline Ck 07005000 9/25/2008 7:36 D No 5.61 5 112% Maline Ck 07005000 10/14/2008 7:13 D No 4.75 5 95% Maline Ck 07005000 10/22/2008 7:30 D No 7.21 5 144% Maline Ck Maline_1 4/19/2002 23:59 W S No 5.5 5 110% Maline Ck Maline_1 2/26/2003 23:59 D B No 9 5 180% Maline Ck Maline_1 9/3/2003 23:59 W S No 5.4 5 108% Maline Ck Maline_1 6/22/2004 23:59 W S Yes 4.3 5 86% Maline Ck Maline_1 11/8/2004 23:59 D B No 7.4 5 148% Maline Ck Maline_1 12/15/2004 23:59 D B No 13.8 5 276% Maline Ck Maline_1 1/18/2005 8:54 D B No 10.8 5 216% Maline Ck Maline_1 2/23/2005 9:46 W B No 8.5 5 170% Maline Ck Maline_1 3/22/2005 9:46 W S No 4.1 5 82% Maline Ck Maline_1 4/26/2005 8:32 W S No 7.9 5 158% Maline Ck Maline_1 9/21/2005 23:59 W S No 6.4 5 128% Maline Ck Maline_1 10/12/2005 23:59 D B No 6.3 5 126% Maline Ck Maline_1 11/28/2005 23:59 W S No 8.3 5 166% Maline Ck Maline_1 12/20/2005 23:59 D B No 12.7 5 254% Maline Ck Maline_1 2/8/2006 0:00 W S No 11 5 220% Maline Ck Maline_1 3/21/2006 0:00 W S No 8.9 5 178% Maline Ck Maline_1 7/31/2006 0:00 W S No 5.5 5 110% Maline Ck Maline_1 10/23/2006 0:00 D S No 7.2 5 144% Maline Ck Maline_1 11/6/2006 0:00 D B No 8.5 5 170% Maline Ck Maline_1 11/14/2006 0:00 D S No 5.1 5 102% Maline Ck Maline_1 1/29/2007 0:00 D B No 14.9 5 298% Maline Ck Maline_1 2/20/2007 0:00 D S No 13.4 5 268% Maline Ck Maline_1 3/6/2007 0:00 D B No 11.2 5 224% Maline Ck Maline_1 3/14/2007 0:00 W S No 10.7 5 214% Maline Ck Maline_1 3/26/2007 0:00 D B No 8.4 5 168% Maline Ck Maline_1 5/16/2007 0:00 W S Yes 9.2 5 184% Maline Ck Maline_1 8/28/2007 0:00 D B No 6.1 5 122% Maline Ck Maline_1 9/12/2007 0:00 D B No 5.5 5 110% Maline Ck Maline_1 9/25/2007 0:00 D B No 5.9 5 118% Maline Ck Maline_1 10/9/2007 0:00 D B No 6.6 5 132% Maline Ck Maline_1 10/24/2007 0:00 D S No 7.4 5 148% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Maline Ck Maline_1 11/15/2007 0:00 D B No 6.4 5 128% Maline Ck Maline_1 12/27/2007 0:00 W S No 12 5 240% Maline Ck Maline_1 1/3/2008 23:59 D No 14 5 280% Maline Ck Maline_1 2/7/2008 23:59 W No 15 5 300% Maline Ck Maline_1 3/13/2008 23:59 W No 9 5 180% Maline Ck Maline_1 4/16/2008 23:59 D Yes 11.5 5 230% Maline Ck Maline_1 5/8/2008 23:59 W Yes 8.2 5 164% Maline Ck Maline_1 7/30/2008 23:59 W Yes 5.8 5 116% Maline Ck Maline_1 9/3/2008 23:59 W No 5.7 5 114% Maline Ck Maline_1 10/8/2008 23:59 D No 6.6 5 132% Maline Ck Maline_1 11/12/2008 23:59 W No 8.5 5 170% Maline Ck Maline_1 12/9/2008 23:59 W No 10 5 200% Maline Ck Maline_2 9/19/2002 23:59 W S No 3.9 5 78% Maline Ck Maline_2 10/10/2003 23:59 W S No 5.8 5 116% Maline Ck Maline_2 11/18/2003 23:59 W S No 5.3 5 106% Maline Ck Maline_2 5/14/2004 23:59 W S No 6.7 5 134% Lower RDP 07010097 10/29/2002 3:00 W S No 8.8 5 176% Lower RDP 07010097 12/17/2002 11:00 W B No 12.7 5 254% Lower RDP 07010097 2/3/2003 10:45 W B No 11.5 5 230% Lower RDP 07010097 3/19/2003 11:09 W S No 8.1 5 162% Lower RDP 07010097 8/11/2003 13:15 D B No 13.4 5 268% Lower RDP 07010097 10/9/2003 14:55 W S No 4.1 5 82% Lower RDP 07010097 12/4/2003 10:20 W S No 13.3 5 266% Lower RDP 07010097 2/18/2004 8:50 D S No 15.4 5 308% Lower RDP 07010097 3/4/2004 11:00 W S No 11 5 220% Lower RDP 07010097 5/17/2004 12:00 D B No 15.1 5 302% Lower RDP 07010097 8/3/2004 15:45 W B No 18.9 5 378% Lower RDP 07010097 10/4/2004 12:55 D B No 16.3 5 326% Lower RDP 07010097 10/12/2004 17:30 W S No 6.24 5 125% Lower RDP 07010097 3/22/2005 9:55 W S No 10.6 5 212% Lower RDP 07010097 4/25/2005 11:40 W S No 12.7 5 254% Lower RDP 07010097 6/21/2005 15:05 D B No 15.2 5 304% Lower RDP 07010097 8/10/2005 8:30 D B No 5.1 5 102% Lower RDP 07010097 10/4/2005 15:45 D B No 15.4 5 308% Lower RDP 07010097 10/31/2005 15:52 W S No 8.1 5 162% Lower RDP 07010097 4/4/2006 15:00 W S No 13.9 5 278% Lower RDP 07010097 4/6/2006 16:37 W S No 6.6 5 132% Lower RDP 07010097 6/6/2006 9:40 W B No 9.8 5 196% Lower RDP 07010097 8/22/2006 14:40 W B No 18 5 360% Lower RDP 07010097 10/3/2006 13:30 D B No 15.1 5 302% Lower RDP 07010097 10/16/2006 12:58 W S No 8.7 5 174% Lower RDP 07010097 1/16/2007 11:50 W S No 14.5 5 290% Lower RDP 07010097 2/5/2007 10:30 W B No 10.1 5 202% Lower RDP 07010097 3/19/2007 11:35 D B No 11.8 5 236% Lower RDP 07010097 4/23/2007 9:50 D B Yes 4.2 5 84% Lower RDP 07010097 4/24/2007 22:46 W S No 2.9 5 58% Lower RDP 07010097 5/22/2007 13:00 D B No 1.6 5 32% Lower RDP 07010097 6/19/2007 14:45 D S No 12.3 5 246% Lower RDP 07010097 7/23/2007 10:30 D B No 9.4 5 188% Lower RDP 07010097 8/8/2007 10:10 D B No 8.9 5 178% Lower RDP 07010097 9/12/2007 12:55 D B No 10.3 5 206% Lower RDP 07010097 1/29/2008 10:00 D No 9.02 5 180% Lower RDP 07010097 2/27/2008 12:20 D No 12.98 5 260% Lower RDP 07010097 3/11/2008 11:15 D No 9.47 5 189% Lower RDP 07010097 4/8/2008 11:07 W Yes 9.34 5 187% Lower RDP 07010097 5/19/2008 11:38 D Yes 3.81 5 76% Lower RDP 07010097 7/17/2008 22:55 D Yes 10.47 5 209% Lower RDP 07010097 8/14/2008 11:09 D No 6.5 5 130% Lower RDP 07010097 8/28/2008 10:28 W No 5.53 5 111% Lower RDP 07010097 9/4/2008 5:45 W No 7.88 5 158% Lower RDP 07010097 9/25/2008 11:34 D No 7.44 5 149% Lower RDP 07010097 10/14/2008 10:37 D No 6.33 5 127% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Lower RDP 07010097 10/22/2008 11:02 D No 9.13 5 183% Lower RDP RDP-4 5/14/2004 23:59 W S No 5.3 5 106% Lower RDP SITE 1 5/8/2002 23:59 W S Yes 5.4 5 108% Lower RDP SITE 1 10/29/2002 23:59 W S No 7.5 5 150% Lower RDP SITE 1 3/12/2003 23:59 W S No 9 5 180% Lower RDP SITE 1 4/24/2003 23:59 W S No 7 5 140% Lower RDP SITE 1 6/25/2003 23:59 W S No 7.6 5 152% Lower RDP SITE 1 6/26/2003 23:59 W S No 4.7 5 94% Lower RDP SITE 1 9/2/2003 23:59 W S No 6.3 5 126% Lower RDP SITE 1 3/4/2004 23:59 W S No 8.4 5 168% Lower RDP SITE 1 5/19/2004 23:59 W S No 5.5 5 110% Lower RDP SITE 1 7/8/2004 23:59 D B Yes 4.6 5 92% Lower RDP SITE 1 8/17/2004 23:59 D B No 6.6 5 132% Lower RDP SITE 1 10/12/2004 23:59 W S No 5 5 100% Lower RDP SITE 1 12/7/2004 23:59 W S Yes 7.5 5 150% Lower RDP SITE 1 1/4/2005 9:19 W S Yes 9 5 180% Lower RDP SITE 1 6/9/2005 9:07 W S Yes 5.4 5 108% Lower RDP SITE 1 7/12/2005 23:59 W S No 7.8 5 156% Lower RDP SITE 1 11/15/2005 23:59 W S No 6 5 120% Lower RDP SITE 1 5/2/2006 0:00 W S Yes 4.7 5 94% Lower RDP SITE 1 10/17/2006 0:00 W S No 7 5 140% Lower RDP SITE 1 10/3/2007 0:00 W S No 6 5 120% Lower RDP SITE 1 12/10/2007 0:00 W S No 9.7 5 194% Lower RDP SITE 1 2/5/2008 23:59 W No 10 5 200% Lower RDP SITE 1 3/3/2008 23:59 W Yes 10 5 200% Lower RDP SITE 3 10/29/2002 23:59 W S No 7.1 5 142% Lower RDP SITE 3 4/24/2003 23:59 W S No 6.9 5 138% Lower RDP SITE 3 6/26/2003 23:59 W S No 4.3 5 86% Lower RDP SITE 3 9/2/2003 23:59 W S No 6.5 5 130% Lower RDP SITE 3 3/4/2004 23:59 W S No 8 5 160% Lower RDP SITE 3 5/19/2004 23:59 W S No 6.5 5 130% Lower RDP SITE 3 10/12/2004 23:59 W S No 3.4 5 68% Lower RDP SITE 3 12/7/2004 23:59 W S No 7.3 5 146% Lower RDP SITE 3 1/4/2005 9:57 W S No 9 5 180% Lower RDP SITE 3 6/9/2005 11:52 W S No 5.3 5 106% Lower RDP SITE 3 7/12/2005 23:59 W S No 7.4 5 148% Lower RDP SITE 3 11/15/2005 23:59 W S No 6.6 5 132% Lower RDP SITE 3 5/2/2006 0:00 W S No 5.2 5 104% Lower RDP SITE 3 10/17/2006 0:00 W S No 7.1 5 142% Lower RDP SITE 3 10/3/2007 0:00 W S No 5.6 5 112% Lower RDP SITE 3 12/10/2007 0:00 W S No 10.2 5 204% Lower RDP SITE 3 2/5/2008 23:59 W No 10.4 5 208% Lower RDP SITE 3 3/3/2008 23:59 W No 9.3 5 186% Lower RDP SITE 4 10/29/2002 23:59 W S No 7.3 5 146% Lower RDP SITE 4 4/24/2003 23:59 W S No 7.8 5 156% Lower RDP SITE 4 6/26/2003 23:59 W S No 4.6 5 92% Lower RDP SITE 4 9/2/2003 23:59 W S No 5 5 100% Lower RDP SITE 4 3/4/2004 23:59 W S No 8.5 5 170% Lower RDP SITE 4 5/19/2004 23:59 W S No 6.1 5 122% Lower RDP SITE 4 10/12/2004 23:59 W S No 4.3 5 86% Lower RDP SITE 4 12/7/2004 23:59 W S No 7.3 5 146% Lower RDP SITE 4 1/4/2005 10:14 W S No 7.9 5 158% Lower RDP SITE 4 6/9/2005 9:54 W S No 5.6 5 112% Lower RDP SITE 4 7/12/2005 23:59 W S No 6.8 5 136% Lower RDP SITE 4 11/15/2005 23:59 W S No 6.6 5 132% Lower RDP SITE 4 5/2/2006 0:00 W S No 6 5 120% Lower RDP SITE 4 10/17/2006 0:00 W S No 7.3 5 146% Lower RDP SITE 4 4/11/2007 0:00 W S No 7.7 5 154% Lower RDP SITE 4 5/2/2007 0:00 W S No 6.4 5 128% Lower RDP SITE 4 10/3/2007 0:00 W S No 6.5 5 130% Lower RDP SITE 4 12/10/2007 0:00 W S No 10 5 200% Lower RDP SITE 4 2/5/2008 23:59 W No 9.9 5 198% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Lower RDP SITE 4 3/3/2008 23:59 W No 10.3 5 206% Gravois Ck SITE 2 5/8/2002 23:59 W S Yes 6.6 5 132% Gravois Ck SITE 2 10/29/2002 23:59 W S No 7.9 5 158% Gravois Ck SITE 2 3/19/2003 23:59 W S No 7.4 5 148% Gravois Ck SITE 2 4/24/2003 23:59 W S No 7.1 5 142% Gravois Ck SITE 2 6/25/2003 23:59 W S No 6.6 5 132% Gravois Ck SITE 2 6/26/2003 23:59 W S No 5.5 5 110% Gravois Ck SITE 2 9/2/2003 23:59 W S No 6.5 5 130% Gravois Ck SITE 2 3/4/2004 23:59 W S No 8.2 5 164% Gravois Ck SITE 2 5/19/2004 23:59 W S No 6.2 5 124% Gravois Ck SITE 2 7/8/2004 23:59 D B No 5.4 5 108% Gravois Ck SITE 2 8/17/2004 23:59 D B No 7.9 5 158% Gravois Ck SITE 2 10/12/2004 23:59 W S No 4.9 5 98% Gravois Ck SITE 2 12/7/2004 23:59 W S No 7.4 5 148% Gravois Ck SITE 2 1/4/2005 9:37 W S No 8.5 5 170% Gravois Ck SITE 2 6/9/2005 9:26 W S No 5.9 5 118% Gravois Ck SITE 2 7/12/2005 23:59 W S No 7.4 5 148% Gravois Ck SITE 2 11/15/2005 23:59 W S No 7.1 5 142% Gravois Ck SITE 2 5/2/2006 0:00 W S No 5.3 5 106% Gravois Ck SITE 2 10/17/2006 0:00 W S No 7 5 140% Gravois Ck SITE 2 4/11/2007 0:00 W S Yes 9.3 5 186% Gravois Ck SITE 2 5/2/2007 0:00 W S Yes 7 5 140% Gravois Ck SITE 2 10/3/2007 0:00 W S No 6.4 5 128% Gravois Ck SITE 2 12/10/2007 0:00 W S No 11.4 5 228% Gravois Ck SITE 2 2/5/2008 23:59 W No 10.6 5 212% Gravois Ck SITE 2 3/3/2008 23:59 W No 10.9 5 218% Deer Ck Deer_1 2/12/2003 23:59 D B No 10 5 200% Deer Ck Deer_1 7/16/2003 23:59 D B No 5.8 5 116% Deer Ck Deer_1 5/24/2004 23:59 W B No 2.8 5 56% Deer Ck Deer_1 9/27/2004 23:59 D B No 4.6 5 92% Deer Ck Deer_1 10/12/2004 23:59 W S No 4.7 5 94% Deer Ck Deer_1 10/20/2004 23:59 W S No 4.8 5 96% Deer Ck Deer_1 2/9/2005 10:26 W S No 11 5 220% Deer Ck Deer_1 3/2/2005 10:32 D B No 10.9 5 218% Deer Ck Deer_1 3/9/2005 10:37 D B No 9.7 5 194% Deer Ck Deer_1 8/2/2005 23:59 D B No 5.9 5 118% Deer Ck Deer_1 9/28/2005 23:59 W S No 6 5 120% Deer Ck Deer_1 11/30/2005 23:59 W S No 8.2 5 164% Deer Ck Deer_1 2/15/2006 0:00 W B No 7.5 5 150% Deer Ck Deer_1 3/21/2006 0:00 W S No 10.4 5 208% Deer Ck Deer_1 8/8/2006 0:00 D B No 6.4 5 128% Deer Ck Deer_1 9/25/2006 0:00 D B No 5.6 5 112% Deer Ck Deer_1 10/31/2006 0:00 D B No 6.1 5 122% Deer Ck Deer_1 11/28/2006 0:00 D B No 6.8 5 136% Deer Ck Deer_1 12/18/2006 0:00 D B No 10 5 200% Deer Ck Deer_1 1/22/2007 0:00 D S No 11.5 5 230% Deer Ck Deer_1 2/13/2007 0:00 W S No 11 5 220% Deer Ck Deer_1 2/27/2007 0:00 D S No 11.8 5 236% Deer Ck Deer_1 3/12/2007 0:00 D B No 13.6 5 272% Deer Ck Deer_1 3/19/2007 0:00 D B No 13 5 260% Deer Ck Deer_1 4/3/2007 0:00 W S No 7.5 5 150% Deer Ck Deer_1 8/1/2007 0:00 D B No 10.2 5 204% Deer Ck Deer_1 9/5/2007 0:00 W S No 7.1 5 142% Deer Ck Deer_1 10/2/2007 0:00 W B No 5.9 5 118% Deer Ck Deer_1 10/17/2007 0:00 W S No 7.8 5 156% Deer Ck Deer_1 11/7/2007 0:00 D B No 8.4 5 168% Deer Ck Deer_1 12/18/2007 0:00 D B No 11.9 5 238% Deer Ck Deer_1 1/16/2008 23:59 D No 12 5 240% Deer Ck Deer_1 1/31/2008 23:59 W No 13.5 5 270% Deer Ck Deer_1 3/27/2008 23:59 W No 8.8 5 176% Deer Ck Deer_1 4/3/2008 23:59 W No 10.2 5 204% Deer Ck Deer_1 4/30/2008 23:59 D No 7.3 5 146% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Deer Ck Deer_1 5/28/2008 23:59 W No 7.7 5 154% Deer Ck Deer_1 9/10/2008 23:59 D No 7.3 5 146% Deer Ck Deer_1 10/29/2008 23:59 D No 7.8 5 156% Deer Ck Deer_1 12/3/2008 23:59 W No 10 5 200% Deer Ck SITE 5 10/29/2002 23:59 W S No 6.3 5 126% Deer Ck SITE 5 4/24/2003 23:59 W S No 8.5 5 170% Deer Ck SITE 5 6/26/2003 23:59 W S No 6 5 120% Deer Ck SITE 5 9/2/2003 23:59 W S No 5.5 5 110% Deer Ck SITE 5 3/4/2004 23:59 W S No 8.5 5 170% Deer Ck SITE 5 5/19/2004 23:59 W S No 6.9 5 138% Deer Ck SITE 5 10/12/2004 23:59 W S No 4.5 5 90% Deer Ck SITE 5 12/7/2004 23:59 W S No 7.2 5 144% Deer Ck SITE 5 1/4/2005 10:39 W S No 8 5 160% Deer Ck SITE 5 6/9/2005 10:18 W S No 5.2 5 104% Deer Ck SITE 5 7/12/2005 23:59 W S No 7.1 5 142% Deer Ck SITE 5 11/15/2005 23:59 W S No 7.2 5 144% Deer Ck SITE 5 5/2/2006 0:00 W S No 5.3 5 106% Deer Ck SITE 5 10/17/2006 0:00 W S No 6.4 5 128% Deer Ck SITE 5 4/11/2007 0:00 W S No 7.5 5 150% Deer Ck SITE 5 5/2/2007 0:00 W S No 6.2 5 124% Deer Ck SITE 5 10/3/2007 0:00 W S No 5.7 5 114% Deer Ck SITE 5 12/10/2007 0:00 W S No 9.7 5 194% Deer Ck SITE 5 2/5/2008 23:59 W No 7.8 5 156% Deer Ck SITE 5 3/3/2008 23:59 W No 11 5 220% Black Ck Black_1 2/19/2003 23:59 W S No 11 5 220% Black Ck Black_1 7/23/2003 23:59 D B No 3.2 5 64% Black Ck Black_1 5/24/2004 23:59 W B No 3.2 5 64% Black Ck Black_1 9/27/2004 23:59 D B No 5.7 5 114% Black Ck Black_1 10/12/2004 23:59 W S No 5.1 5 102% Black Ck Black_1 10/20/2004 23:59 W S No 4.7 5 94% Black Ck Black_1 2/9/2005 10:06 W S No 9.5 5 190% Black Ck Black_1 3/9/2005 10:02 D B No 9 5 180% Black Ck Black_1 4/13/2005 11:40 W S No 6.9 5 138% Black Ck Black_1 8/2/2005 23:59 D B No 5.9 5 118% Black Ck Black_1 9/28/2005 23:59 W S No 6.2 5 124% Black Ck Black_1 11/30/2005 23:59 W S No 8 5 160% Black Ck Black_1 2/15/2006 0:00 W B No 5.6 5 112% Black Ck Black_1 3/21/2006 0:00 W S No 8.6 5 172% Black Ck Black_1 8/8/2006 0:00 D B No 5.5 5 110% Black Ck Black_1 9/25/2006 0:00 D B No 5.6 5 112% Black Ck Black_1 10/31/2006 0:00 D B No 5.7 5 114% Black Ck Black_1 11/28/2006 0:00 D B No 5.6 5 112% Black Ck Black_1 12/18/2006 0:00 D B No 8 5 160% Black Ck Black_1 1/22/2007 0:00 D S No 11.5 5 230% Black Ck Black_1 2/13/2007 0:00 W S No 9.8 5 196% Black Ck Black_1 2/27/2007 0:00 D S No 10.9 5 218% Black Ck Black_1 3/12/2007 0:00 D B No 6.8 5 136% Black Ck Black_1 3/19/2007 0:00 D B No 10.1 5 202% Black Ck Black_1 4/3/2007 0:00 W S No 6.5 5 130% Black Ck Black_1 8/1/2007 0:00 D B No 6 5 120% Black Ck Black_1 9/5/2007 0:00 W S No 5.5 5 110% Black Ck Black_1 10/2/2007 0:00 W B No 6.6 5 132% Black Ck Black_1 10/17/2007 0:00 W S No 6.5 5 130% Black Ck Black_1 11/7/2007 0:00 D B No 7.9 5 158% Black Ck Black_1 12/18/2007 0:00 D B No 12 5 240% Black Ck Black_1 1/16/2008 23:59 D No 12 5 240% Black Ck Black_1 1/31/2008 23:59 W No 12.8 5 256% Black Ck Black_1 3/27/2008 23:59 W No 10.1 5 202% Black Ck Black_1 4/3/2008 23:59 W No 10.2 5 204% Black Ck Black_1 4/30/2008 23:59 D No 8.9 5 178% Black Ck Black_1 5/28/2008 23:59 W No 7 5 140% Black Ck Black_1 9/10/2008 23:59 D No 6.5 5 130% Table C-1: Comparison of Dissolved Oxygen Concentrations to Daily Average Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Black Ck Black_1 10/29/2008 23:59 D No 6.7 5 134% Black Ck Black_1 12/3/2008 23:59 W No 6.5 5 130% Table C-2: Comparison of Dissolved Oxygen Concentrations to Daily Average Criterion for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Deer Ck Deer_3 2/12/2003 23:59 D B No 10 5 200% Deer Ck Deer_3 7/16/2003 23:59 D B No 4.6 5 92% Deer Ck Deer_3 5/24/2004 23:59 W B No 3 5 60% Deer Ck Deer_3 9/27/2004 23:59 D B No 3.3 5 66% Deer Ck Deer_3 10/12/2004 23:59 W S No 5.2 5 104% Deer Ck Deer_3 10/20/2004 23:59 W S No 4.5 5 90% Deer Ck Deer_3 2/9/2005 9:53 W S No 10.4 5 208% Deer Ck Deer_3 3/2/2005 10:16 D B No 11 5 220% Deer Ck Deer_3 3/9/2005 10:15 D B No 10 5 200% Deer Ck Deer_3 8/2/2005 23:59 D B No 5.6 5 112% Deer Ck Deer_3 9/28/2005 23:59 W S No 5.8 5 116% Deer Ck Deer_3 11/30/2005 23:59 W S No 7.1 5 142% Deer Ck Deer_3 2/15/2006 0:00 W B No 6.9 5 138% Deer Ck Deer_3 3/21/2006 0:00 W S No 8.9 5 178% Deer Ck Deer_3 8/8/2006 0:00 D B No 5.8 5 116% Deer Ck Deer_3 9/25/2006 0:00 D B No 5.5 5 110% Deer Ck Deer_3 10/31/2006 0:00 D B No 5.5 5 110% Deer Ck Deer_3 11/28/2006 0:00 D B No 6.8 5 136% Deer Ck Deer_3 12/18/2006 0:00 D B No 8.2 5 164% Deer Ck Deer_3 1/22/2007 0:00 D S No 12.6 5 252% Deer Ck Deer_3 2/13/2007 0:00 W S No 10.2 5 204% Deer Ck Deer_3 2/27/2007 0:00 D S No 11.7 5 234% Deer Ck Deer_3 3/12/2007 0:00 D B No 10.8 5 216% Deer Ck Deer_3 3/19/2007 0:00 D B No 10.6 5 212% Deer Ck Deer_3 4/3/2007 0:00 W S No 7.5 5 150% Deer Ck Deer_3 8/1/2007 0:00 D B No 8.4 5 168% Deer Ck Deer_3 9/5/2007 0:00 W S No 5.6 5 112% Deer Ck Deer_3 10/2/2007 0:00 W B No 6.1 5 122% Deer Ck Deer_3 10/17/2007 0:00 W S No 6 5 120% Deer Ck Deer_3 11/7/2007 0:00 D B No 6.6 5 132% Deer Ck Deer_3 12/18/2007 0:00 D B No 10.9 5 218% Deer Ck Deer_3 1/16/2008 23:59 D No 10.5 5 210% Deer Ck Deer_3 1/31/2008 23:59 W No 13 5 260% Deer Ck Deer_3 3/27/2008 23:59 W No 10.8 5 216% Deer Ck Deer_3 4/3/2008 23:59 W No 10.4 5 208% Deer Ck Deer_3 4/30/2008 23:59 D No 7 5 140% Deer Ck Deer_3 5/28/2008 23:59 W No 8 5 160% Deer Ck Deer_3 9/10/2008 23:59 D No 6.1 5 122% Deer Ck Deer_3 10/29/2008 23:59 D No 6.6 5 132% Deer Ck Deer_3 12/3/2008 23:59 W No 7.8 5 156% Engelholm Engel_1 10/20/2004 23:59 W S No 5.3 5 106% Engelholm Engel_1 12/15/2004 23:59 D B No 10 5 200% Engelholm Engel_1 2/9/2005 11:34 W S No 10.7 5 214% Engelholm Engel_1 2/23/2005 12:01 W B No 10 5 200% Engelholm Engel_1 3/9/2005 9:30 D B No 9.9 5 198% Engelholm Engel_1 3/22/2005 12:05 W S No 4 5 80% Engelholm Engel_1 8/2/2005 23:59 D B No 4.2 5 84% Engelholm Engel_1 9/28/2005 23:59 W S No 5.5 5 110% Engelholm Engel_1 11/30/2005 23:59 W S No 8.9 5 178% Engelholm Engel_1 2/15/2006 0:00 W B No 7.2 5 144% Engelholm Engel_1 3/21/2006 0:00 W S No 9.9 5 198% Engelholm Engel_1 8/8/2006 0:00 D B No 6 5 120% Engelholm Engel_1 9/25/2006 0:00 D B No 5.7 5 114% Engelholm Engel_1 10/31/2006 0:00 D B No 6.4 5 128% Engelholm Engel_1 11/28/2006 0:00 D B No 6.1 5 122% Engelholm Engel_1 12/18/2006 0:00 D B No 10.6 5 212% Engelholm Engel_1 1/22/2007 0:00 D S No 11.9 5 238% Engelholm Engel_1 2/27/2007 0:00 D S No 11.5 5 230% Engelholm Engel_1 3/12/2007 0:00 D B No 9 5 180% Engelholm Engel_1 3/19/2007 0:00 D B No 10.8 5 216% Engelholm Engel_1 4/3/2007 0:00 W S No 8.7 5 174% Engelholm Engel_1 4/25/2007 0:00 W S No 8.3 5 166% Table C-2: Comparison of Dissolved Oxygen Concentrations to Daily Average Criterion for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Engelholm Engel_1 5/16/2007 0:00 W S No 9.9 5 198% Engelholm Engel_1 8/1/2007 0:00 D B No 6.9 5 138% Engelholm Engel_1 9/5/2007 0:00 W S No 5.5 5 110% Engelholm Engel_1 10/2/2007 0:00 W S No 5.8 5 116% Engelholm Engel_1 10/17/2007 0:00 W S No 5.9 5 118% Engelholm Engel_1 11/7/2007 0:00 D B No 6.8 5 136% Engelholm Engel_1 12/18/2007 0:00 D B No 10.8 5 216% Engelholm Engel_1 1/16/2008 23:59 D No 11.4 5 228% Engelholm Engel_1 1/31/2008 23:59 W No 11.9 5 238% Engelholm Engel_1 3/27/2008 23:59 W No 8 5 160% Engelholm Engel_1 4/3/2008 23:59 W No 7.7 5 154% Engelholm Engel_1 4/30/2008 23:59 D No 7.4 5 148% Engelholm Engel_1 5/28/2008 23:59 W No 10 5 200% Engelholm Engel_1 9/10/2008 23:59 D No 7.3 5 146% Engelholm Engel_1 10/29/2008 23:59 D No 6.1 5 122% Engelholm Engel_1 12/3/2008 23:59 W No 8 5 160% Middle RDP SITE 6 10/29/2002 23:59 W S No 6.2 5 124% Middle RDP SITE 6 4/24/2003 23:59 W S No 8 5 160% Middle RDP SITE 6 6/26/2003 23:59 W S No 4.8 5 96% Middle RDP SITE 6 9/2/2003 23:59 W S No 5.2 5 104% Middle RDP SITE 6 3/4/2004 23:59 W S No 8.5 5 170% Middle RDP SITE 6 5/19/2004 23:59 W S No 5.5 5 110% Middle RDP SITE 6 10/12/2004 23:59 W S No 5.7 5 114% Middle RDP SITE 6 12/7/2004 23:59 W S No 6.7 5 134% Middle RDP SITE 6 1/4/2005 11:22 W S No 8.6 5 172% Middle RDP SITE 6 6/9/2005 10:45 W S No 5.7 5 114% Middle RDP SITE 6 7/12/2005 23:59 W S No 6.7 5 134% Middle RDP SITE 6 11/15/2005 23:59 W S No 7.3 5 146% Middle RDP SITE 6 5/2/2006 0:00 W S No 5 5 100% Middle RDP SITE 6 10/17/2006 0:00 W S No 6.8 5 136% Middle RDP SITE 6 4/11/2007 0:00 W S No 9 5 180% Middle RDP SITE 6 5/2/2007 0:00 W S No 8.1 5 162% Middle RDP SITE 6 10/3/2007 0:00 W S No 6.6 5 132% Middle RDP SITE 6 12/10/2007 0:00 W S No 10.4 5 208% Middle RDP SITE 6 2/5/2008 23:59 W No 10.2 5 204% Middle RDP SITE 6 3/3/2008 23:59 W No 10.6 5 212% Middle RDP SITE 7 10/29/2002 23:59 W S No 5.2 5 104% Middle RDP SITE 7 4/24/2003 23:59 W S No 7.7 5 154% Middle RDP SITE 7 6/26/2003 23:59 W S No 5.4 5 108% Middle RDP SITE 7 9/2/2003 23:59 W S No 5.3 5 106% Middle RDP SITE 7 3/4/2004 23:59 W S No 8.5 5 170% Middle RDP SITE 7 5/19/2004 23:59 W S No 6.1 5 122% Middle RDP SITE 7 12/7/2004 23:59 W S No 6.8 5 136% Middle RDP SITE 7 1/4/2005 11:44 W S No 9 5 180% Middle RDP SITE 7 6/9/2005 11:16 W S No 6.4 5 128% Middle RDP SITE 7 7/12/2005 23:59 W S No 6.9 5 138% Middle RDP SITE 7 11/15/2005 23:59 W S No 8 5 160% Middle RDP SITE 7 5/2/2006 0:00 W S No 6.3 5 126% Middle RDP SITE 7 10/17/2006 0:00 W S No 7.4 5 148% Middle RDP SITE 7 4/11/2007 0:00 W S No 7.4 5 148% Middle RDP SITE 7 5/2/2007 0:00 W S No 10 5 200% Middle RDP SITE 7 10/3/2007 0:00 W S No 5.7 5 114% Middle RDP SITE 7 12/10/2007 0:00 W S No 7.8 5 156% Middle RDP SITE 7 2/5/2008 23:59 W No 10.1 5 202% Middle RDP SITE 7 3/3/2008 23:59 W No 9 5 180% Upper RDP 07010022 8/19/1997 13:48 W S No 8.6 5 172% Upper RDP 07010022 8/26/1997 15:35 W B No 0.4 5 8% Upper RDP 07010022 12/16/1997 8:35 D B No 5.9 5 118% Upper RDP 07010022 2/24/1998 14:30 D B No 19.6 5 392% Upper RDP 07010022 4/3/1998 9:08 W S No 10.3 5 206% Upper RDP 07010022 6/22/1998 14:45 W S No 10.4 5 208% Upper RDP 07010022 12/1/1998 8:35 D B No 5.6 5 112% Table C-2: Comparison of Dissolved Oxygen Concentrations to Daily Average Criterion for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Upper RDP 07010022 2/11/1999 10:10 W S No 7.1 5 142% Upper RDP 07010022 2/11/1999 15:16 W S No 9.1 5 182% Upper RDP 07010022 5/12/1999 16:09 W S No 5.1 5 102% Upper RDP 07010022 6/17/1999 8:50 D B No 4.8 5 96% Upper RDP 07010022 8/3/1999 8:28 D B No 3.7 5 74% Upper RDP 07010022 1/6/2000 7:40 D B No 12.2 5 244% Upper RDP 07010022 2/18/2000 1:33 W S No 13 5 260% Upper RDP 07010022 2/29/2000 7:56 D B No 9 5 180% Upper RDP 07010022 5/7/2000 1:21 W S No 7.8 5 156% Upper RDP 07010022 6/15/2000 8:15 D B No 3.7 5 74% Upper RDP 07010022 8/1/2000 10:15 D B No 4.5 5 90% Upper RDP 07010022 12/19/2000 9:20 D B No 9.9 5 198% Upper RDP 07010022 2/27/2001 8:20 W S No 11.2 5 224% Upper RDP 07010022 3/15/2001 20:02 W S No 9.3 5 186% Upper RDP 07010022 4/9/2001 23:32 W S No 8.1 5 162% Upper RDP 07010022 5/29/2001 13:10 W S No 6.1 5 122% Upper RDP 07010022 8/27/2001 11:30 D B No 5.7 5 114% Upper RDP 07010022 10/24/2001 13:22 W S No 8.9 5 178% Upper RDP 07010022 12/11/2001 13:50 D B No 4.2 5 84% Upper RDP 07010022 2/4/2002 10:48 D B No 12.1 5 242% Upper RDP 07010022 3/9/2002 2:17 W S No 7.7 5 154% Upper RDP 07010022 3/25/2002 3:00 W S No 12.2 5 244% Upper RDP 07010022 5/30/2002 9:55 W S No 6.6 5 132% Upper RDP 07010022 8/8/2002 14:40 W S No 8.8 5 176% Upper RDP 07010022 10/29/2002 1:56 W S No 7 5 140% Upper RDP 07010022 12/17/2002 14:10 W B No 8.8 5 176% Upper RDP 07010022 2/4/2003 15:00 D B No 7.5 5 150% Upper RDP 07010022 3/19/2003 8:52 W S No 9.4 5 188% Upper RDP 07010022 6/9/2003 11:30 D B No 6.5 5 130% Upper RDP 07010022 8/12/2003 12:45 D B No 1 5 20% Upper RDP 07010022 10/9/2003 13:37 W S No 8.6 5 172% Upper RDP 07010022 12/17/2003 8:35 D B No 12 5 240% Upper RDP 07010022 2/18/2004 8:45 D S No 7.6 5 152% Upper RDP 07010022 3/3/2004 20:21 W S No 9.2 5 184% Upper RDP 07010022 5/18/2004 9:30 W S No 7 5 140% Upper RDP 07010022 8/3/2004 10:15 W B No 4 5 80% Upper RDP 07010022 10/5/2004 13:45 D B No 11.7 5 234% Upper RDP 07010022 10/12/2004 16:14 W S No 7 5 140% Upper RDP 07010022 3/22/2005 9:49 W S No 12.3 5 246% Upper RDP 07010022 4/25/2005 13:00 W S No 9.5 5 190% Upper RDP 07010022 6/22/2005 11:00 D B No 4.4 5 88% Upper RDP 07010022 8/8/2005 13:30 D B No 2.2 5 44% Upper RDP 07010022 10/3/2005 15:30 D B No 12.6 5 252% Upper RDP 07010022 10/20/2005 18:45 W S No 6.3 5 126% Upper RDP 07010022 10/31/2005 20:00 W S No 8.2 5 164% Upper RDP 07010022 4/2/2006 18:00 W S No 6.8 5 136% Upper RDP 07010022 4/3/2006 14:45 W S No 16.8 5 336% Upper RDP 07010022 6/6/2006 8:08 W B No 6.1 5 122% Upper RDP 07010022 8/22/2006 8:00 W B No 2.8 5 56% Upper RDP 07010022 10/2/2006 14:00 D B No 4.6 5 92% Upper RDP 07010022 10/16/2006 13:00 W S No 8.7 5 174% Upper RDP 07010022 1/16/2007 13:00 W S No 15.8 5 316% Upper RDP 07010022 2/5/2007 12:25 W B No 15.9 5 318% Upper RDP 07010022 3/19/2007 13:05 D B No 17.9 5 358% Upper RDP 07010022 4/3/2007 12:27 W S No 9.1 5 182% Upper RDP 07010022 4/10/2007 13:25 W S No 15.7 5 314% Upper RDP 07010022 5/21/2007 14:15 D B No 14.3 5 286% Upper RDP 07010022 6/18/2007 12:23 W S No 10.7 5 214% Upper RDP 07010022 7/23/2007 11:45 D B No 5.7 5 114% Upper RDP 07010022 8/8/2007 11:45 D B No 5.8 5 116% Upper RDP 07010022 9/12/2007 14:00 D B No 4.5 5 90% Upper RDP 07010022 1/29/2008 11:05 D No 7.94 5 159% Table C-2: Comparison of Dissolved Oxygen Concentrations to Daily Average Criterion for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW DO (mg/L) RemarkID Daily Average Criterion DO / Criterion Upper RDP 07010022 2/27/2008 13:24 D No 12.18 5 244% Upper RDP 07010022 3/11/2008 12:12 D No 13.43 5 269% Upper RDP 07010022 4/8/2008 12:33 W No 16.36 5 327% Upper RDP 07010022 5/19/2008 12:36 D No 17.76 5 355% Upper RDP 07010022 6/3/2008 15:27 W No 9.45 5 189% Upper RDP 07010022 7/17/2008 12:00 D No 3.94 5 79% Upper RDP 07010022 8/14/2008 12:06 D No 9.61 5 192% Upper RDP 07010022 8/28/2008 11:18 W No 7.36 5 147% Upper RDP 07010022 9/4/2008 6:16 W No 7.56 5 151% Upper RDP 07010022 9/25/2008 12:25 D No 19.99 5 400% Upper RDP 07010022 10/14/2008 11:37 D No 7.66 5 153% Upper RDP 07010022 10/22/2008 11:53 D No 11.09 5 222% Upper RDP SITE 8 5/8/2002 23:59 W S No 4.7 5 94% Upper RDP SITE 8 10/29/2002 23:59 W S No 6 5 120% Upper RDP SITE 8 4/24/2003 23:59 W S No 8.1 5 162% Upper RDP SITE 8 6/26/2003 23:59 W S No 5.6 5 112% Upper RDP SITE 8 9/2/2003 23:59 W S No 6 5 120% Upper RDP SITE 8 3/4/2004 23:59 W S No 9 5 180% Upper RDP SITE 8 5/19/2004 23:59 W S No 5.5 5 110% Upper RDP SITE 8 10/12/2004 23:59 W S No 5 5 100% Upper RDP SITE 8 12/7/2004 23:59 W S No 6.8 5 136% Upper RDP SITE 8 1/4/2005 12:14 W S No 8 5 160% Upper RDP SITE 8 6/9/2005 12:41 W S No 6 5 120% Upper RDP SITE 8 7/12/2005 23:59 W S No 7.3 5 146% Upper RDP SITE 8 11/15/2005 23:59 W S No 7 5 140% Upper RDP SITE 8 5/2/2006 0:00 W S No 5.2 5 104% Upper RDP SITE 8 10/17/2006 0:00 W S No 6 5 120% Upper RDP SITE 8 4/11/2007 0:00 W S No 8.7 5 174% Upper RDP SITE 8 5/2/2007 0:00 W S No 6.6 5 132% Upper RDP SITE 8 10/3/2007 0:00 W S No 6.2 5 124% Upper RDP SITE 8 12/10/2007 0:00 W S No 9.3 5 186% Upper RDP SITE 8 2/5/2008 23:59 W No 11.9 5 238% Upper RDP SITE 8 3/3/2008 23:59 W No 10.1 5 202% Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Mississippi 05587455 10/16/1997 11:25 D B No 6 E Mississippi 05587455 11/12/1997 13:35 D B No 52 Mississippi 05587455 12/4/1997 10:45 W S No 130 Mississippi 05587455 1/22/1998 10:20 W B No 54 Mississippi 05587455 2/17/1998 12:25 W S No 100 Mississippi 05587455 3/17/1998 10:15 W S No 28 E Mississippi 05587455 3/23/1998 13:15 D B No 180 Mississippi 05587455 4/14/1998 11:10 W S No 120 Mississippi 05587455 5/5/1998 10:10 D B No 150 Mississippi 05587455 5/19/1998 9:35 D B No 68 Mississippi 05587455 6/2/1998 9:45 D B No 58 Mississippi 05587455 6/15/1998 12:50 W S No 1,600 Mississippi 05587455 7/6/1998 13:40 W S No 540 Mississippi 05587455 9/1/1998 10:45 W S No 24 E Mississippi 05587455 10/14/1998 12:15 D B No 86 Mississippi 05587455 11/23/1998 13:05 D B No 120 Mississippi 05587455 12/8/1998 10:35 W S No 42 E Mississippi 05587455 2/2/1999 10:30 W S No 260 Mississippi 05587455 2/25/1999 13:05 D B No 8 E Mississippi 05587455 3/17/1999 13:35 D B No 10 E Mississippi 05587455 4/12/1999 13:20 D B No 270 Mississippi 05587455 4/20/1999 10:45 D B No 1,200 Mississippi 05587455 5/10/1999 13:50 D B No 78 Mississippi 05587455 5/24/1999 13:55 D B No 170 Mississippi 05587455 6/7/1999 14:10 D B No 240 Mississippi 05587455 6/21/1999 14:05 W B No 220 Mississippi 05587455 7/24/1999 14:20 D B No 6 E Mississippi 05587455 8/9/1999 13:40 W S No 18 E Mississippi 05587455 9/13/1999 13:30 W S No 12 E Mississippi 05587455 10/19/1999 15:05 D B No 27 E Mississippi 05587455 11/22/1999 13:15 D B No 11 E Mississippi 05587455 12/7/1999 13:35 W B No 220 Mississippi 05587455 1/19/2000 12:25 W S No 160 E Mississippi 05587455 2/14/2000 13:55 D B No 8 E Mississippi 05587455 3/13/2000 13:05 W S No 150 E Y N N N N N 137 78 Mississippi 05587455 3/13/2000 13:05 W S No 150 E Mississippi 05587455 4/3/2000 14:00 D B No 32 E Mississippi 05587455 5/4/2000 10:35 D B No 68 Mississippi 05587455 6/9/2000 19:05 D B No 22 E Mississippi 05587455 6/26/2000 14:10 W S No 320 E Mississippi 05587455 7/10/2000 13:50 D B No 260 Mississippi 05587455 8/11/2000 19:25 D S No 28 Mississippi 05587455 9/11/2000 13:55 W S No 10 E Mississippi 05587455 10/2/2000 14:10 D B No 4 E Mississippi 05587455 11/7/2000 10:50 W S No 58 Mississippi 05587455 2/6/2001 11:05 D B No 64 Mississippi 05587455 2/21/2001 13:15 W B No 8 E Mississippi 05587455 3/1/2001 11:25 W S No 160 Mississippi 05587455 3/7/2001 13:10 D B No 2 E Mississippi 05587455 3/21/2001 12:40 D B No 140 Mississippi 05587455 4/2/2001 13:45 W B No 29 Mississippi 05587455 4/16/2001 14:35 W S No 140 Mississippi 05587455 4/30/2001 14:10 W B No 65 E Mississippi 05587455 5/14/2001 14:45 D B No 120 Mississippi 05587455 6/6/2001 13:30 W S No 940 Mississippi 05587455 6/11/2001 13:25 D B No 200 Mississippi 05587455 7/16/2001 14:20 D B No 12 E Mississippi 05587455 8/6/2001 14:25 D B No 2 E Mississippi 05587455 9/12/2001 12:45 D B No 2 Mississippi 05587455 10/15/2001 14:20 W S No 87 E Mississippi 05587455 11/19/2001 13:25 W S No 7 E Mississippi 05587455 12/3/2001 13:25 D B No 92 E Mississippi 05587455 1/16/2002 13:10 D B No 1 E Mississippi 05587455 2/11/2002 14:15 D B No 4 < N N N N N N 38 44 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Mississippi 05587455 3/12/2002 13:45 D B No 35 E Mississippi 05587455 4/1/2002 14:05 D B No 11 E Mississippi 05587455 5/6/2002 14:05 W S No 30 E Mississippi 05587455 6/3/2002 13:55 D B No 8 E Mississippi 05587455 7/8/2002 14:10 D B No 4 E Mississippi 05587455 8/12/2002 14:25 D B No 3 E Mississippi 05587455 9/9/2002 14:15 D B No 1 E Mississippi 05587455 10/21/2002 13:20 D S No 110 E Mississippi 05587455 11/6/2002 14:00 W S No 32 Mississippi 05587455 12/2/2002 13:45 D B No 8 E Mississippi 05587455 2/19/2003 12:55 W S No 28 Mississippi 05587455 3/4/2003 10:25 D B No 24 Mississippi 05587455 3/18/2003 10:45 W B No 56 Mississippi 05587455 4/21/2003 14:05 W S No 6 E Mississippi 05587455 5/5/2003 13:45 W S No 110 Mississippi 05587455 6/2/2003 13:00 W S No 7 E Mississippi 05587455 7/7/2003 13:35 D B No 8 E Mississippi 05587455 8/4/2003 13:45 W S No 55 Mississippi 05587455 9/8/2003 14:05 D B No 27 Mississippi 05587455 10/22/2003 13:10 D B No 1 E Mississippi 05587455 11/12/2003 12:25 D B No 27 Mississippi 05587455 12/1/2003 13:45 D B No 34 Mississippi 05587455 1/12/2004 14:45 D B No 11 E Mississippi 05587455 2/23/2004 13:40 W B No 13 E Mississippi 05587455 3/8/2004 14:45 D B No 60 E Mississippi 05587455 4/14/2004 13:00 D B No 21 Mississippi 05587455 5/10/2004 13:10 W B No 22 Mississippi 05587455 6/14/2004 13:15 D B No 200 E Mississippi 05587455 7/12/2004 13:25 D B No 49 Mississippi 05587455 8/9/2004 13:15 D B No 120 Mississippi 05587455 9/20/2004 13:45 D B No 23 Mississippi 05587455 10/25/2004 12:30 D B No 17 E Mississippi 05587455 11/8/2004 13:00 D B No 120 Mississippi 05587455 12/6/2004 13:35 W S No 65 Mississippi 05587455 1/10/2005 13:30 D B No 130 N N N N N N NNN 9 13 42 Mississippi 05587455 1/10/2005 13:30 D B No 130 Mississippi 05587455 2/8/2005 13:15 W S No 20 Mississippi 05587455 3/7/2005 13:35 W S No 4 E Mississippi 05587455 4/12/2005 9:45 W S No 27 E Mississippi 05587455 4/21/2005 15:15 W S No 20 E Mississippi 05587455 5/9/2005 12:40 W B No 1 E Mississippi 05587455 6/10/2005 11:55 W S No 6 E Mississippi 05587455 6/20/2005 14:00 D B No 110 Mississippi 05587455 7/11/2005 12:15 W S No 18 k Mississippi 05587455 7/20/2005 12:30 W B No 25 k Mississippi 05587455 8/8/2005 12:50 D B No 5 k Mississippi 05587455 9/12/2005 12:40 D B No 8 k Mississippi 05587455 10/3/2005 14:10 D B No 5 E Mississippi 05587455 11/7/2005 13:30 W S No 40 Mississippi 05587455 12/12/2005 12:45 D B No 8 E Mississippi 05587455 1/9/2006 13:55 W B No 13 E Mississippi 05587455 2/8/2006 13:15 W S No 13 E Mississippi 05587455 3/13/2006 13:20 W S No 32 E Mississippi 05587455 4/11/2006 10:35 D B No 33 E Mississippi 05587455 5/2/2006 16:10 W S No 42 E Mississippi 05587455 6/2/2006 18:15 W S No 17 E Mississippi 05587455 6/12/2006 15:45 W S No 260 Mississippi 05587455 7/25/2006 10:30 D B No 6 E Mississippi 05587455 8/23/2006 10:25 W S No 1 E Mississippi 05587455 9/20/2006 12:00 D B No 20 Mississippi 05587455 10/18/2006 10:25 W S No 30 E Mississippi 05587455 10/24/2006 9:00 D B No 25 E Mississippi 05587455 11/27/2006 14:25 D B No 10 E Mississippi 05587455 12/11/2006 15:15 D S No 44 N N N N N N 11 20 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Mississippi 05587455 1/10/2007 13:05 D B No 27 E Mississippi 05587455 2/28/2007 14:05 W S No 80 Mississippi 05587455 3/26/2007 13:20 D B No 33 E Mississippi 05587455 4/12/2007 9:45 W S No 42 E Mississippi 05587455 4/24/2007 9:40 W S No 12 E Mississippi 05587455 5/30/2007 8:53 W B No 4 E Mississippi 05587455 6/26/2007 10:10 D S No 20 Mississippi 05587455 7/17/2007 9:50 W B No 2 E Mississippi 05587455 8/22/2007 10:35 D B No 4 E Mississippi 05587455 9/7/2007 10:15 W S No 10 E Mississippi 05587455 10/22/2007 12:35 W No 970 E Mississippi 05587455 11/28/2007 13:00 W No 4 E Mississippi 05587455 12/19/2007 13:05 D B No 54 Mississippi 05587455 1/9/2008 13:25 W No 1,100 Mississippi 05587455 7/15/2008 12:10 D No 170 Mississippi 05587455 7/29/2008 16:20 W No 600 Mississippi 05587455 9/11/2008 11:32 W No 200 Mississippi 05587455 9/24/2008 12:35 D No 110 Mississippi 05587455 10/1/2008 11:40 W No 20 Mississippi 05587455 10/8/2008 11:44 D No 50 Mississippi 05587455 10/16/2008 11:23 W No 20 Mississippi 05587455 10/21/2008 10:55 D No 40 Mississippi 05587455 10/28/2008 11:37 D No 60 Mississippi 07005500 10/26/2004 10:10 W S No 20 E Mississippi 07005500 4/12/2005 14:25 W S No 12 E Mississippi 07005500 4/22/2005 9:50 W S No 10 E Mississippi 07005500 5/10/2005 9:30 D B No 22 Mississippi 07005500 6/10/2005 15:25 W S No 230 Mississippi 07005500 6/21/2005 10:05 D B No 280 Mississippi 07005500 7/12/2005 9:50 W S No 28 k Mississippi 07005500 7/20/2005 15:40 W B No 21 Mississippi 07005500 8/9/2005 10:15 D B No 13 k Mississippi 07005500 10/4/2005 10:10 D B No 41 Mississippi 07005500 4/10/2006 12:35 D B No 30 E Mississippi 07005500 5/1/2006 13:10 W S No 28 E N N N N N N N N N 15 78 34 Mississippi 07005500 5/1/2006 13:10 W S No 28 E Mississippi 07005500 5/2/2006 9:50 W S No 180 E Mississippi 07005500 6/2/2006 11:40 W S No 12 E Mississippi 07005500 6/5/2006 12:40 D B No 54 Mississippi 07005500 6/12/2006 9:50 W S No 1,100 Mississippi 07005500 7/24/2006 13:15 D B No 44 Mississippi 07005500 8/22/2006 12:20 W B No 200 Mississippi 07005500 10/17/2006 10:50 W S No 110 Mississippi 07005500 10/23/2006 13:25 D B No 55 E Mississippi 07005500 4/11/2007 11:40 W S No 120 E Mississippi 07005500 4/23/2007 14:10 D B No 20 E Mississippi 07005500 5/29/2007 14:15 W S No 40 E Mississippi 07005500 6/25/2007 15:05 W S No 46 Mississippi 07005500 7/16/2007 14:25 D B No 4 < Mississippi 07005500 8/21/2007 13:40 W B No 32 E Mississippi 07005500 9/7/2007 16:10 W S No 30 E Mississippi 07005500 7/15/2008 19:15 D No 120 Mississippi 07005500 7/31/2008 8:30 W No 650 Mississippi 07005500 9/11/2008 16:38 W No 70 Mississippi 07005500 9/24/2008 9:30 D No 160 Mississippi 07005500 10/1/2008 9:53 W No 170 Mississippi 07005500 10/8/2008 9:16 D No 330 Mississippi 07005500 10/16/2008 9:03 W No 180 Mississippi 07005500 10/21/2008 8:42 D No 130 Mississippi 07005500 10/28/2008 9:31 D No 840 X Mississippi 07010000 10/26/2004 9:15 W S No 42 Mississippi 07010000 4/12/2005 13:35 W S No 18 E Mississippi 07010000 4/22/2005 9:10 W S No 33 E Mississippi 07010000 5/10/2005 8:55 D B No 12 E Y N N N N N N N Y 75 29 215 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Mississippi 07010000 6/10/2005 14:40 W S No 190 Mississippi 07010000 6/21/2005 9:20 D B No 620 Mississippi 07010000 7/12/2005 9:10 W S No 44 Mississippi 07010000 7/20/2005 15:10 W B No 40 Mississippi 07010000 8/9/2005 9:30 D B No 13 Ek Mississippi 07010000 8/9/2005 9:31 D B No 15 Ek Mississippi 07010000 10/4/2005 9:20 D B No 89 Mississippi 07010000 4/10/2006 11:55 D B No 50 E Mississippi 07010000 5/1/2006 11:35 W S No 16 E Mississippi 07010000 5/2/2006 9:10 W S No 140 E Mississippi 07010000 6/2/2006 11:10 W S No 55 E Mississippi 07010000 6/5/2006 12:00 D B No 66 Mississippi 07010000 6/12/2006 9:10 W S No 370 E Mississippi 07010000 7/24/2006 13:58 D B No 350 Mississippi 07010000 8/22/2006 13:05 W B No 120 Mississippi 07010000 10/17/2006 11:50 W S No 240 Mississippi 07010000 10/23/2006 13:55 D B No 80 E Mississippi 07010000 4/11/2007 11:00 W S No 160 E Mississippi 07010000 4/23/2007 13:30 D B No 15 E Mississippi 07010000 5/29/2007 13:37 W S No 60 E Mississippi 07010000 6/25/2007 13:25 W S No 37 E Mississippi 07010000 7/16/2007 13:50 D B No 16 E Mississippi 07010000 8/21/2007 13:00 W B No 100 Mississippi 07010000 9/7/2007 13:25 W S No 170 Mississippi 07010000 7/15/2008 19:40 D No 240 Mississippi 07010000 7/31/2008 10:00 W No 750 Mississippi 07010000 9/11/2008 17:16 W No 150 Mississippi 07010000 9/24/2008 10:00 D No 320 Mississippi 07010000 10/1/2008 9:22 W No 220 Mississippi 07010000 10/8/2008 9:38 D No 560 Mississippi 07010000 10/16/2008 9:23 W No 290 Mississippi 07010000 10/21/2008 9:09 D No 460 Mississippi 07010000 10/28/2008 9:51 D No 880 X Mississippi 07010220 10/26/2004 12:30 W S No 64 Mississippi 07010220 4/12/2005 16:20 W S No 24 E N N N N N Y Y N N N N N 44 102 55 368 Mississippi 07010220 4/12/2005 16:20 W S No 24 E Mississippi 07010220 4/22/2005 11:05 W S No 1,600 Mississippi 07010220 5/10/2005 10:50 D B No 240 Mississippi 07010220 6/10/2005 16:30 W S No 330 Mississippi 07010220 6/21/2005 11:15 D B No 940 Mississippi 07010220 7/12/2005 11:00 W S No 1,200 Mississippi 07010220 7/20/2005 16:50 W B No 400 k Mississippi 07010220 8/9/2005 11:25 D B No 250 Mississippi 07010220 10/4/2005 11:35 D B No 370 Mississippi 07010220 4/10/2006 13:50 D B No 180 E Mississippi 07010220 5/1/2006 14:10 W S No 10 E Mississippi 07010220 5/2/2006 11:05 W S No 270 E Mississippi 07010220 6/2/2006 13:00 W S No 20 E Mississippi 07010220 6/5/2006 13:50 D B No 25 E Mississippi 07010220 6/12/2006 11:05 W S No 600 Mississippi 07010220 7/24/2006 15:00 D B No 760 Mississippi 07010220 8/22/2006 14:08 W B No 30 E Mississippi 07010220 10/17/2006 12:50 W S No 460 Mississippi 07010220 10/23/2006 15:05 D B No 20 E Mississippi 07010220 4/11/2007 13:05 W S No 1,300 Mississippi 07010220 4/23/2007 12:35 D B No 50 E Mississippi 07010220 5/29/2007 11:57 W S No 83 E Mississippi 07010220 6/25/2007 12:35 W S No 77 E Mississippi 07010220 7/16/2007 12:05 D B No 120 Mississippi 07010220 8/21/2007 11:30 W B No 230 Mississippi 07010220 9/7/2007 14:10 W S No 480 Mississippi 07010220 7/15/2008 18:00 D No 230 Mississippi 07010220 7/31/2008 12:00 W No 880 E Mississippi 07010220 9/11/2008 15:35 W No 130 Y Y N N N N Y N N 369 89 177 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Mississippi 07010220 9/24/2008 8:30 D No 530 Mississippi 07010220 10/1/2008 8:20 W No 190 Mississippi 07010220 10/8/2008 8:17 D No 440 Mississippi 07010220 10/16/2008 8:09 W No 600 Mississippi 07010220 10/21/2008 7:48 D No 420 Mississippi 07010220 10/28/2008 8:14 D No 920 X Mississippi 07019370 10/26/2004 11:50 W S No 580 Mississippi 07019370 4/12/2005 15:50 W S No 74 Mississippi 07019370 4/22/2005 11:45 W S No 150 Mississippi 07019370 5/10/2005 11:15 D B No 58 Mississippi 07019370 6/10/2005 17:00 W S No 280 Mississippi 07019370 6/21/2005 12:00 D B No 400 Mississippi 07019370 7/12/2005 11:30 W S No 700 Mississippi 07019370 7/20/2005 17:10 W B No 410 k Mississippi 07019370 8/9/2005 11:50 D B No 270 Mississippi 07019370 10/4/2005 12:15 D B No 110 Mississippi 07019370 4/10/2006 14:20 D B No 20 < Mississippi 07019370 5/1/2006 14:45 W S No 30 E Mississippi 07019370 5/2/2006 11:35 W S No 1,100 Mississippi 07019370 6/2/2006 13:35 W S No 130 E Mississippi 07019370 6/5/2006 14:15 D B No 35 E Mississippi 07019370 6/12/2006 11:25 W S No 680 Mississippi 07019370 7/24/2006 15:32 D B No 390 Mississippi 07019370 8/22/2006 14:35 W B No 52 Mississippi 07019370 10/17/2006 13:13 W S No 480 Mississippi 07019370 10/23/2006 15:45 D B No 56 E Mississippi 07019370 4/11/2007 13:35 W S No 100 E Mississippi 07019370 4/23/2007 11:55 D B No 70 E Mississippi 07019370 5/29/2007 12:28 W S No 100 E Mississippi 07019370 6/25/2007 12:10 W S No 120 Mississippi 07019370 7/16/2007 12:30 D B No 92 Mississippi 07019370 8/21/2007 12:00 W B No 300 Mississippi 07019370 9/7/2007 14:35 W S No 170 E Mississippi 07019370 7/15/2008 17:15 D No 330 Mississippi 07019370 7/31/2008 13:50 W No 960 E Y Y N N N N Y N N NNY 401 204 127 122 Mississippi 07019370 7/31/2008 13:50 W No 960 E Mississippi 07019370 9/11/2008 15:03 W No 130 Mississippi 07019370 9/24/2008 7:50 D No 400 Mississippi 07019370 10/1/2008 7:44 W No 240 Mississippi 07019370 10/8/2008 7:41 D No 340 Mississippi 07019370 10/16/2008 7:28 W No 880 Mississippi 07019370 10/21/2008 7:17 D No 390 Mississippi 07019370 10/28/2008 7:40 D No 880 X Maline Ck 07005000 8/1/1996 9:45 D B No 2,900 Maline Ck 07005000 9/23/1996 15:30 W S No 54,000 Maline Ck 07005000 12/11/1996 11:30 D B No 184 Maline Ck 07005000 3/5/1997 13:15 D B No 350 E Maline Ck 07005000 5/25/1997 23:50 W S No 60,000 E Maline Ck 07005000 6/10/1997 9:15 D B No 910 E Maline Ck 07005000 8/26/1997 8:30 W B No 4,300 Maline Ck 07005000 9/2/1997 16:34 W S No 1,000 E Maline Ck 07005000 12/15/1997 14:50 D B No 500 Maline Ck 07005000 2/24/1998 10:45 D B No 100 Maline Ck 07005000 4/15/1998 6:55 W S Yes 40,000 Maline Ck 07005000 6/23/1998 8:15 W S Yes 1,700 Maline Ck 07005000 12/1/1998 10:35 D S No 1,100 Maline Ck 07005000 2/10/1999 13:55 D B No 1,100 Maline Ck 07005000 2/11/1999 16:30 W S No 24,000 Maline Ck 07005000 5/4/1999 23:22 W S Yes 23,000 Maline Ck 07005000 6/17/1999 12:35 D B No 540 Maline Ck 07005000 8/3/1999 9:40 D B No 800 E Maline Ck 07005000 12/9/1999 15:43 W S No 10,000 Maline Ck 07005000 1/6/2000 10:05 D B No 2,400 Maline Ck 07005000 2/29/2000 9:58 D B No 240 E Y Y N420 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Maline Ck 07005000 4/7/2000 3:38 W S No 5,800 Maline Ck 07005000 6/15/2000 10:15 D B No 400 Maline Ck 07005000 8/1/2000 12:00 D S No 1,600 Maline Ck 07005000 12/18/2000 17:10 W B No 1,300 E Maline Ck 07005000 2/9/2001 10:54 W S No 1,200 E Maline Ck 07005000 2/27/2001 15:55 W S No 210 E Maline Ck 07005000 4/10/2001 23:31 W S No 280,000 Maline Ck 07005000 5/29/2001 15:40 W B No 3,000 Maline Ck 07005000 8/27/2001 13:45 D B No 760 Maline Ck 07005000 10/24/2001 0:45 W S No 7,000 Maline Ck 07005000 12/10/2001 17:00 D B No 42 E Maline Ck 07005000 2/5/2002 9:00 D B No 120 Maline Ck 07005000 3/9/2002 3:32 W S No 800 E Maline Ck 07005000 5/30/2002 8:15 W S No 2,500 Maline Ck 07005000 8/8/2002 11:30 W S No 730 Maline Ck 07005000 10/29/2002 5:16 W S No 16,000 Maline Ck 07005000 12/17/2002 9:35 W B No 1,600 E Maline Ck 07005000 2/4/2003 10:15 D B No 140 E Maline Ck 07005000 4/16/2003 21:09 W S No 12,000 Maline Ck 07005000 6/9/2003 14:25 D B No 640 Maline Ck 07005000 8/12/2003 9:40 D B No 480 Maline Ck 07005000 10/9/2003 14:42 W S No 21,000 Maline Ck 07005000 12/4/2003 9:30 W S No 290 Maline Ck 07005000 2/9/2004 14:30 D S No 10 E Maline Ck 07005000 3/4/2004 12:38 W S No 4,800 Maline Ck 07005000 5/17/2004 14:15 D B No 150 E Maline Ck 07005000 8/4/2004 10:00 W S No 9,400 E Maline Ck 07005000 10/5/2004 12:00 D B No 670 Maline Ck 07005000 10/26/2004 17:00 W S No 2,800 Maline Ck 07005000 3/22/2005 13:22 W S No 10,000 Maline Ck 07005000 4/25/2005 14:30 W S No 2,100 Maline Ck 07005000 6/20/2005 13:50 D B No 2,100 Maline Ck 07005000 8/8/2005 12:13 D B No 5,200 k Maline Ck 07005000 10/3/2005 13:30 D B No 8,200 Maline Ck 07005000 10/31/2005 16:03 W S No 5,000 Y Y Y3,932 Maline Ck 07005000 10/31/2005 16:03 W S No 5,000 Maline Ck 07005000 4/4/2006 10:15 W S No 600 E Maline Ck 07005000 5/1/2006 22:18 W S No 14,000 Maline Ck 07005000 6/6/2006 10:58 W B No 860 Maline Ck 07005000 8/21/2006 16:15 D B No 2,400 Maline Ck 07005000 10/2/2006 12:45 D B No 50 E Maline Ck 07005000 10/16/2006 15:27 W S No 930 E Maline Ck 07005000 1/16/2007 14:10 W S No 2,400 Maline Ck 07005000 2/5/2007 13:55 W S No 20 E Maline Ck 07005000 3/19/2007 14:25 D B No 230 Maline Ck 07005000 4/3/2007 13:37 W S No 13,000 Maline Ck 07005000 4/10/2007 10:50 W S No 400 E Maline Ck 07005000 5/21/2007 10:45 D B No 180 Maline Ck 07005000 6/18/2007 10:08 W S No 160 Maline Ck 07005000 7/23/2007 15:30 D B No 340 Maline Ck 07005000 8/8/2007 16:45 D B No 20 E Maline Ck 07005000 9/12/2007 15:25 D B No 580 Maline Ck 07005000 1/29/2008 11:55 D No 10 U Maline Ck 07005000 2/27/2008 7:01 D No 370 Maline Ck 07005000 3/11/2008 7:19 D No 455 Maline Ck 07005000 4/8/2008 7:05 W No 108 Maline Ck 07005000 6/3/2008 12:00 W No 3,400 Maline Ck 07005000 7/15/2008 6:55 D No 520 Maline Ck 07005000 8/14/2008 7:00 D No 4,200 Maline Ck 07005000 8/28/2008 6:50 W No 1,600 Maline Ck 07005000 9/4/2008 6:07 W No 53,000 Maline Ck 07005000 9/25/2008 7:36 D No 20,000 Maline Ck 07005000 10/14/2008 7:13 D No 200 Maline Ck 07005000 10/22/2008 7:30 D No 880 X Y Y N Y Y N Y Y Y 965 346 1,838 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Maline Ck Maline_1 11/8/2004 23:59 D B No 100 Maline Ck Maline_1 12/15/2004 23:59 D B No 100 < Maline Ck Maline_1 1/18/2005 8:54 D B No 23,000 Maline Ck Maline_1 2/23/2005 9:46 W B No 37,000 Maline Ck Maline_1 3/22/2005 9:46 W S No 4,400 Maline Ck Maline_1 4/26/2005 8:32 W S No 360 Maline Ck Maline_1 9/21/2005 23:59 W S No 200 Maline Ck Maline_1 10/12/2005 23:59 D B No 100 < Maline Ck Maline_1 11/28/2005 23:59 W S No 910 Maline Ck Maline_1 12/20/2005 23:59 D B No 100 < Maline Ck Maline_1 2/8/2006 0:00 W S No 100 < Maline Ck Maline_1 3/21/2006 0:00 W S No 100 < Maline Ck Maline_1 7/31/2006 0:00 W S No 100 < Maline Ck Maline_1 10/23/2006 0:00 D S No 100 Maline Ck Maline_1 11/6/2006 0:00 D B No 100 Maline Ck Maline_1 11/14/2006 0:00 D S No 100 < Maline Ck Maline_1 5/16/2007 0:00 W S Yes 2,000 Maline Ck Maline_1 8/28/2007 0:00 D B No 210 Maline Ck Maline_1 9/12/2007 0:00 D B No 30 Maline Ck Maline_1 9/25/2007 0:00 D B No 500 Maline Ck Maline_1 10/9/2007 0:00 D B No 160 Maline Ck Maline_1 10/24/2007 0:00 D S No 200 Maline Ck Maline_1 4/16/2008 23:59 D Yes 54 Maline Ck Maline_1 5/8/2008 23:59 W Yes 13,000 Maline Ck Maline_1 7/30/2008 23:59 W Yes 680 Maline Ck Maline_1 9/3/2008 23:59 W No 680 Maline Ck Maline_1 10/8/2008 23:59 D No 1,200 Lower RDP 07010097 10/29/2002 3:00 W S No 39,000 E Lower RDP 07010097 12/17/2002 11:00 W B No 4 E Lower RDP 07010097 2/3/2003 10:45 W B No 23 E Lower RDP 07010097 3/19/2003 11:09 W S No 25,000 Lower RDP 07010097 6/9/2003 15:50 D B No 240 Lower RDP 07010097 8/11/2003 13:15 D B No 270 Lower RDP 07010097 10/9/2003 14:55 W S No 63,000 Lower RDP 07010097 12/4/2003 10:20 W S No 830 E Y Y N Y Y N 242 828 Lower RDP 07010097 12/4/2003 10:20 W S No 830 E Lower RDP 07010097 2/18/2004 8:50 D S No 52 E Lower RDP 07010097 3/4/2004 11:00 W S No 29,000 Lower RDP 07010097 5/17/2004 12:00 D B No 42 Lower RDP 07010097 8/3/2004 15:45 W B No 88 Lower RDP 07010097 10/4/2004 12:55 D B No 20 E Lower RDP 07010097 10/12/2004 17:30 W S No 3,700 Lower RDP 07010097 10/12/2004 17:31 W S No 2,800 Lower RDP 07010097 3/22/2005 9:55 W S No 41,000 Lower RDP 07010097 4/25/2005 11:40 W S No 750 E Lower RDP 07010097 6/21/2005 15:05 D B No 40 k Lower RDP 07010097 8/10/2005 8:30 D B No 150 Lower RDP 07010097 10/4/2005 15:45 D B No 20 E Lower RDP 07010097 10/31/2005 15:52 W S No 72,000 Lower RDP 07010097 4/4/2006 15:00 W S No 650 E Lower RDP 07010097 4/6/2006 16:37 W S No 2,000 E Lower RDP 07010097 6/6/2006 9:40 W B No 330 E Lower RDP 07010097 8/22/2006 14:40 W B No 600 E Lower RDP 07010097 10/3/2006 13:30 D B No 140 Lower RDP 07010097 10/16/2006 12:58 W S No 94,000 Lower RDP 07010097 1/16/2007 11:50 W S No 1,000 Lower RDP 07010097 2/5/2007 10:30 W B No 10 < Lower RDP 07010097 3/19/2007 11:35 D B No 4,300 E Lower RDP 07010097 4/23/2007 9:50 D B Yes 650 Lower RDP 07010097 4/24/2007 22:46 W S No 39,000 Lower RDP 07010097 5/22/2007 13:00 D B No 1,200 E Lower RDP 07010097 6/19/2007 14:45 D S No 4,600 E Lower RDP 07010097 7/23/2007 10:30 D B No 590 Lower RDP 07010097 8/8/2007 10:10 D B No 460 Y Y N Y Y Y Y Y N Y Y Y 238 365 1,225 1,256 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Lower RDP 07010097 9/12/2007 12:55 D B No 130 E Lower RDP 07010097 1/29/2008 10:00 D No 10 U Lower RDP 07010097 2/27/2008 12:20 D No 10 U Lower RDP 07010097 3/11/2008 11:15 D No 10 U Lower RDP 07010097 4/8/2008 11:07 W Yes 99 Lower RDP 07010097 7/17/2008 22:55 D Yes 290 Lower RDP 07010097 8/14/2008 11:09 D No 470 Lower RDP 07010097 8/28/2008 10:28 W No 620 Lower RDP 07010097 9/4/2008 5:45 W No 82,000 Lower RDP 07010097 9/25/2008 11:34 D No 4,600 Lower RDP 07010097 10/14/2008 10:37 D No 220 Lower RDP 07010097 10/22/2008 11:02 D No 10 Lower RDP SITE 1 8/17/2004 23:59 D B No 100 < Lower RDP SITE 1 10/12/2004 23:59 W S No 900 Lower RDP SITE 1 12/7/2004 23:59 W S Yes 3,900 Lower RDP SITE 1 1/4/2005 9:19 W S Yes 5,600 Lower RDP SITE 1 6/9/2005 9:07 W S Yes 15,000 Lower RDP SITE 1 7/12/2005 23:59 W S No 8,200 Lower RDP SITE 1 11/15/2005 23:59 W S No 5,900 Lower RDP SITE 1 5/2/2006 0:00 W S Yes 8,000 Lower RDP SITE 1 10/17/2006 0:00 W S No 100 < Lower RDP SITE 1 10/3/2007 0:00 W S No 15,000 Lower RDP SITE 1 12/10/2007 0:00 W S No 680 Lower RDP SITE 1 2/5/2008 23:59 W No 1,980 Lower RDP SITE 1 3/3/2008 23:59 W Yes 10,000 Lower RDP SITE 4 10/12/2004 23:59 W S No 28,000 Lower RDP SITE 4 12/7/2004 23:59 W S No 4,500 Lower RDP SITE 4 1/4/2005 10:14 W S No 7,100 Lower RDP SITE 4 6/9/2005 9:54 W S No 2,000 Lower RDP SITE 4 7/12/2005 23:59 W S No 4,900 Lower RDP SITE 4 11/15/2005 23:59 W S No 4,000 Lower RDP SITE 4 5/2/2006 0:00 W S No 5,600 Lower RDP SITE 4 10/17/2006 0:00 W S No 100 < Lower RDP SITE 4 4/11/2007 0:00 W S No 2,600 Lower RDP SITE 4 5/2/2007 0:00 W S No 3,100 Y Y N537 Lower RDP SITE 4 5/2/2007 0:00 W S No 3,100 Lower RDP SITE 4 10/3/2007 0:00 W S No 10 < Lower RDP SITE 4 12/10/2007 0:00 W S No 45 Lower RDP SITE 4 2/5/2008 23:59 W No 3,000 Lower RDP SITE 4 3/3/2008 23:59 W No 5,600 Gravois Ck SITE 2 8/17/2004 23:59 D B No 100 < Gravois Ck SITE 2 10/12/2004 23:59 W S No 0 Rejected Gravois Ck SITE 2 12/7/2004 23:59 W S No 1,900 Gravois Ck SITE 2 1/4/2005 9:37 W S No 2,400 Gravois Ck SITE 2 6/9/2005 9:26 W S No 2,100 Gravois Ck SITE 2 7/12/2005 23:59 W S No 2,600 Gravois Ck SITE 2 11/15/2005 23:59 W S No 2,400 Gravois Ck SITE 2 5/2/2006 0:00 W S No 6,800 Gravois Ck SITE 2 10/17/2006 0:00 W S No 100 < Gravois Ck SITE 2 4/11/2007 0:00 W S Yes 2,000 Gravois Ck SITE 2 5/2/2007 0:00 W S Yes 2,700 Gravois Ck SITE 2 10/3/2007 0:00 W S No 3,000 Gravois Ck SITE 2 12/10/2007 0:00 W S No 1,100 Gravois Ck SITE 2 2/5/2008 23:59 W No 590 Gravois Ck SITE 2 3/3/2008 23:59 W No 6,400 Deer Ck Deer_1 9/27/2004 23:59 D B No 100 < Deer Ck Deer_1 10/12/2004 23:59 W S No 6,400 Deer Ck Deer_1 10/20/2004 23:59 W S No 300 Deer Ck Deer_1 2/9/2005 10:26 W S No 1,300 Deer Ck Deer_1 3/2/2005 10:32 D B No 100 < Deer Ck Deer_1 3/9/2005 10:37 D B No 100 < Deer Ck Deer_1 8/2/2005 23:59 D B No 100 < Deer Ck Deer_1 9/28/2005 23:59 W S No 100 < Deer Ck Deer_1 11/30/2005 23:59 W S No 4,600 Table C-3: Comparison of E. Coli Levels to Geometric Mean Criteria for Classified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) Class A > 126 Class B > 206 SCR > 1,134 Deer Ck Deer_1 2/15/2006 0:00 W B No 100 < Deer Ck Deer_1 3/21/2006 0:00 W S No 300 Deer Ck Deer_1 8/8/2006 0:00 D B No 100 < Deer Ck Deer_1 9/25/2006 0:00 D B No 100 < Deer Ck Deer_1 10/31/2006 0:00 D B No 100 < Deer Ck Deer_1 11/28/2006 0:00 D B No 100 < Deer Ck Deer_1 4/3/2007 0:00 W S No 64 Deer Ck Deer_1 8/1/2007 0:00 D B No 560 Deer Ck Deer_1 9/5/2007 0:00 W S No 10 < Deer Ck Deer_1 10/2/2007 0:00 W B No 10 < Deer Ck Deer_1 10/17/2007 0:00 W S No 27 Deer Ck Deer_1 4/3/2008 23:59 W No 4,400 Deer Ck Deer_1 4/30/2008 23:59 D No 36 Deer Ck Deer_1 5/28/2008 23:59 W No 1,500 Deer Ck Deer_1 7/16/2008 23:59 D No 120 Deer Ck Deer_1 9/10/2008 23:59 D No 170 Deer Ck Deer_1 10/29/2008 23:59 D No 27 Deer Ck SITE 5 10/12/2004 23:59 W S No 8,200 Deer Ck SITE 5 12/7/2004 23:59 W S No 2,900 Deer Ck SITE 5 1/4/2005 10:39 W S No 7,400 Deer Ck SITE 5 6/9/2005 10:18 W S No 640 Deer Ck SITE 5 7/12/2005 23:59 W S No 3,100 Deer Ck SITE 5 11/15/2005 23:59 W S No 3,000 Deer Ck SITE 5 5/2/2006 0:00 W S No 8,100 Deer Ck SITE 5 10/17/2006 0:00 W S No 100 < Deer Ck SITE 5 4/11/2007 0:00 W S No 3,600 Deer Ck SITE 5 5/2/2007 0:00 W S No 680 Deer Ck SITE 5 10/3/2007 0:00 W S No 4,600 Deer Ck SITE 5 12/10/2007 0:00 W S No 800 Deer Ck SITE 5 2/5/2008 23:59 W No 1,190 Deer Ck SITE 5 3/3/2008 23:59 W No 6,400 Black Ck Black_1 9/27/2004 23:59 D B No 100 Black Ck Black_1 10/12/2004 23:59 W S No 10,000 Black Ck Black_1 10/20/2004 23:59 W S No 2,000 Black Ck Black_1 2/9/2005 10:06 W S No 200 N N N NYY 40 225 Black Ck Black_1 2/9/2005 10:06 W S No 200 Black Ck Black_1 3/9/2005 10:02 D B No 300 Black Ck Black_1 4/13/2005 11:40 W S No 1,100 Black Ck Black_1 8/2/2005 23:59 D B No 100 < Black Ck Black_1 9/28/2005 23:59 W S No 100 Black Ck Black_1 11/30/2005 23:59 W S No 1,800 Black Ck Black_1 2/15/2006 0:00 W B No 100 < Black Ck Black_1 3/21/2006 0:00 W S No 100 Black Ck Black_1 8/8/2006 0:00 D B No 100 Black Ck Black_1 9/25/2006 0:00 D B No 1,000 Black Ck Black_1 10/31/2006 0:00 D B No 300 Black Ck Black_1 11/28/2006 0:00 D B No 100 Black Ck Black_1 4/3/2007 0:00 W S No 18 Black Ck Black_1 8/1/2007 0:00 D B No 170 Black Ck Black_1 9/5/2007 0:00 W S No 55 Black Ck Black_1 10/2/2007 0:00 W B No 18 Black Ck Black_1 10/17/2007 0:00 W S No 150 Black Ck Black_1 4/3/2008 23:59 W No 2,800 Black Ck Black_1 4/30/2008 23:59 D No 220 Black Ck Black_1 5/28/2008 23:59 W No 600 Black Ck Black_1 7/16/2008 23:59 D No 230 Black Ck Black_1 9/10/2008 23:59 D No 280 Black Ck Black_1 10/29/2008 23:59 D No 73 * Bold text indicates concentrations used in calculation of geometric mean ** Geometric mean concentrations calculated from April 1 to October 31, for seasons with 5 or more data points N N N Y Y N 54 347 This page is blank to facilitate double-sided printing. Table C-4: Comparison of E. Coli Levels to Criteria for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) SCR > 1,134 Deer Ck Deer_3 9/27/2004 23:59 D B No 100 < Deer Ck Deer_3 10/12/2004 23:59 W S No 8000 Deer Ck Deer_3 10/20/2004 23:59 W S No 300 Deer Ck Deer_3 2/9/2005 9:53 W S No 2500 Deer Ck Deer_3 3/2/2005 10:16 D B No 100 < Deer Ck Deer_3 3/9/2005 10:15 D B No 100 < Deer Ck Deer_3 8/2/2005 23:59 D B No 100 < Deer Ck Deer_3 9/28/2005 23:59 W S No 100 < Deer Ck Deer_3 11/30/2005 23:59 W S No 3900 Deer Ck Deer_3 2/15/2006 0:00 W B No 100 < Deer Ck Deer_3 3/21/2006 0:00 W S No 500 Deer Ck Deer_3 8/8/2006 0:00 D B No 100 < Deer Ck Deer_3 9/25/2006 0:00 D B No 100 < Deer Ck Deer_3 10/31/2006 0:00 D B No 100 Deer Ck Deer_3 11/28/2006 0:00 D B No 100 < Deer Ck Deer_3 4/3/2007 0:00 W S No 64 Deer Ck Deer_3 8/1/2007 0:00 D B No 190 Deer Ck Deer_3 9/5/2007 0:00 W S No 10 Deer Ck Deer_3 10/2/2007 0:00 W B No 10 < Deer Ck Deer_3 10/17/2007 0:00 W S No 9 Deer Ck Deer_3 4/3/2008 23:59 W No 2800 Deer Ck Deer_3 4/30/2008 23:59 D No 73 Deer Ck Deer_3 5/28/2008 23:59 W No 2100 Deer Ck Deer_3 7/16/2008 23:59 D No 230 Deer Ck Deer_3 9/10/2008 23:59 D No 190 Deer Ck Deer_3 10/29/2008 23:59 D No 36 Engelholm Engel_1 10/20/2004 23:59 W S No 300 Engelholm Engel_1 12/15/2004 23:59 D B No 100 < Engelholm Engel_1 2/9/2005 11:34 W S No 300 Engelholm Engel_1 2/23/2005 12:01 W B No 100 Engelholm Engel_1 3/9/2005 9:30 D B No 100 < Engelholm Engel_1 3/22/2005 12:05 W S No 1200 Engelholm Engel_1 8/2/2005 23:59 D B No 100 < Engelholm Engel_1 9/28/2005 23:59 W S No 100 Engelholm Engel_1 11/30/2005 23:59 W S No 1000 N N 26 296 Engelholm Engel_1 11/30/2005 23:59 W S No 1000 Engelholm Engel_1 2/15/2006 0:00 W B No 100 < Engelholm Engel_1 3/21/2006 0:00 W S No 100 Engelholm Engel_1 8/8/2006 0:00 D B No 300 Engelholm Engel_1 9/25/2006 0:00 D B No 100 < Engelholm Engel_1 10/31/2006 0:00 D B No 100 < Engelholm Engel_1 11/28/2006 0:00 D B No 100 < Engelholm Engel_1 4/3/2007 0:00 W S No 250 Engelholm Engel_1 4/25/2007 0:00 W S No 470 Engelholm Engel_1 8/1/2007 0:00 D B No 720 Engelholm Engel_1 9/5/2007 0:00 W S No 73 Engelholm Engel_1 10/2/2007 0:00 W S No 110 Engelholm Engel_1 10/17/2007 0:00 W S No 130 Engelholm Engel_1 4/3/2008 23:59 W No 1400 Engelholm Engel_1 4/30/2008 23:59 D No 27 Engelholm Engel_1 5/28/2008 23:59 W No 440 Engelholm Engel_1 7/16/2008 23:59 D No 270 Engelholm Engel_1 9/10/2008 23:59 D No 73 Engelholm Engel_1 10/29/2008 23:59 D No 27 Middle RDP SITE 6 10/12/2004 23:59 W S No 120000 Middle RDP SITE 6 12/7/2004 23:59 W S No 20000 Middle RDP SITE 6 1/4/2005 11:22 W S No 42000 Middle RDP SITE 6 6/9/2005 10:45 W S No 1100 Middle RDP SITE 6 7/12/2005 23:59 W S No 18000 Middle RDP SITE 6 11/15/2005 23:59 W S No 4400 Middle RDP SITE 6 5/2/2006 0:00 W S No 4800 Middle RDP SITE 6 10/17/2006 0:00 W S No 200 Middle RDP SITE 6 4/11/2007 0:00 W S No 4000 Middle RDP SITE 6 5/2/2007 0:00 W S No 54 N N 211 144 Table C-4: Comparison of E. Coli Levels to Criteria for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) SCR > 1,134 Middle RDP SITE 6 10/3/2007 0:00 W S No 13000 Middle RDP SITE 6 12/10/2007 0:00 W S No 200 Middle RDP SITE 6 2/5/2008 23:59 W No 2700 Middle RDP SITE 6 3/3/2008 23:59 W No 14000 Middle RDP SITE 7 12/7/2004 23:59 W S No 40000 Middle RDP SITE 7 1/4/2005 11:44 W S No 100000 Middle RDP SITE 7 6/9/2005 11:16 W S No 1200 Middle RDP SITE 7 7/12/2005 23:59 W S No 27000 Middle RDP SITE 7 11/15/2005 23:59 W S No 5000 Middle RDP SITE 7 5/2/2006 0:00 W S No 9600 Middle RDP SITE 7 10/17/2006 0:00 W S No 300 Middle RDP SITE 7 4/11/2007 0:00 W S No 9500 Middle RDP SITE 7 5/2/2007 0:00 W S No 7200 Middle RDP SITE 7 10/3/2007 0:00 W S No 30000 Middle RDP SITE 7 12/10/2007 0:00 W S No 3400 Middle RDP SITE 7 2/5/2008 23:59 W No 1880 Middle RDP SITE 7 3/3/2008 23:59 W No 13000 Upper RDP 07010022 8/19/1997 13:48 W S No 100000 E Upper RDP 07010022 8/26/1997 15:35 W B No 100000 E Upper RDP 07010022 12/16/1997 8:35 D B No 21000 E Upper RDP 07010022 2/24/1998 14:30 D B No 150 E Upper RDP 07010022 4/3/1998 9:08 W S No 60000 Upper RDP 07010022 6/22/1998 14:45 W S No 1700 Upper RDP 07010022 12/1/1998 8:35 D B No 8000 Upper RDP 07010022 2/11/1999 10:10 W S No 2400 Upper RDP 07010022 2/11/1999 15:16 W S No 36000 Upper RDP 07010022 5/12/1999 16:09 W S No 510000 Upper RDP 07010022 6/17/1999 8:50 D B No 1400 Upper RDP 07010022 8/3/1999 8:28 D B No 2000 Upper RDP 07010022 1/6/2000 7:40 D B No 350 E Upper RDP 07010022 2/18/2000 1:33 W S No 28000 Upper RDP 07010022 2/29/2000 7:56 D B No 180 E Upper RDP 07010022 5/7/2000 1:21 W S No 36000 Upper RDP 07010022 6/15/2000 8:15 D B No 1800 Upper RDP 07010022 8/1/2000 10:15 D B No 3200Upper RDP 07010022 8/1/2000 10:15 D B No 3200 Upper RDP 07010022 12/19/2000 9:20 D B No 1900 Upper RDP 07010022 2/27/2001 8:20 W S No 1700 E Upper RDP 07010022 3/15/2001 20:02 W S No 3500 Upper RDP 07010022 4/9/2001 23:32 W S No 78000 Upper RDP 07010022 5/29/2001 13:10 W S No 1200 Upper RDP 07010022 10/24/2001 13:22 W S No 200000 E Upper RDP 07010022 12/11/2001 13:50 D B No 47 E Upper RDP 07010022 2/4/2002 10:48 D B No 1600 Upper RDP 07010022 3/9/2002 2:17 W S No 9500 E Upper RDP 07010022 5/30/2002 9:55 W S No 7000 Upper RDP 07010022 8/8/2002 14:40 W S No 120 Upper RDP 07010022 10/29/2002 1:56 W S No 39000 Upper RDP 07010022 12/17/2002 14:10 W B No 4 E Upper RDP 07010022 2/4/2003 15:00 D B No 220 Upper RDP 07010022 3/19/2003 8:52 W S No 16000 Upper RDP 07010022 6/9/2003 11:30 D B No 440 Upper RDP 07010022 8/12/2003 12:45 D B No 520 Upper RDP 07010022 10/9/2003 13:37 W S No 2000 E Upper RDP 07010022 12/17/2003 8:35 D B No 2400 E Upper RDP 07010022 2/18/2004 8:45 D S No 1600 > Upper RDP 07010022 3/3/2004 20:21 W S No 41000 E Upper RDP 07010022 5/18/2004 9:30 W S No 6200 Upper RDP 07010022 8/3/2004 10:15 W B No 4000 Upper RDP 07010022 10/5/2004 13:45 D B No 220 Upper RDP 07010022 10/12/2004 16:14 W S No 110000 Upper RDP 07010022 3/22/2005 9:49 W S No 7800 Upper RDP 07010022 4/25/2005 13:00 W S No 9800 Upper RDP 07010022 6/22/2005 11:00 D B No 4200 Table C-4: Comparison of E. Coli Levels to Criteria for Unclassified Water Bodies Water Body StationID DateTime Wet or Dry Storm or Base BW E. coli* (#/100 mL) RemarkID Geomean** (#/100 mL) SCR > 1,134 Upper RDP 07010022 8/8/2005 13:30 D B No 11000 Upper RDP 07010022 10/3/2005 15:30 D B No 480 Upper RDP 07010022 10/20/2005 18:45 W S No 74000 Upper RDP 07010022 10/31/2005 20:00 W S No 15000 Upper RDP 07010022 4/2/2006 18:00 W S No 2400 Upper RDP 07010022 4/3/2006 14:45 W S No 1300 Upper RDP 07010022 6/6/2006 8:08 W B No 5500 Upper RDP 07010022 8/22/2006 8:00 W B No 560 Upper RDP 07010022 10/2/2006 14:00 D B No 550 Upper RDP 07010022 10/16/2006 13:00 W S No 16000 Upper RDP 07010022 1/16/2007 13:00 W S No 2200 Upper RDP 07010022 2/5/2007 12:25 W B No 8400 E Upper RDP 07010022 3/19/2007 13:05 D B No 7800 E Upper RDP 07010022 4/3/2007 12:27 W S No 28000 Upper RDP 07010022 4/10/2007 13:25 W S No 160 E Upper RDP 07010022 5/21/2007 14:15 D B No 810 E Upper RDP 07010022 6/18/2007 12:23 W S No 3700 Upper RDP 07010022 7/23/2007 11:45 D B No 5200 Upper RDP 07010022 8/8/2007 11:45 D B No 1000 Upper RDP 07010022 9/12/2007 14:00 D B No 270 E Upper RDP 07010022 1/29/2008 11:05 D No 900 Upper RDP 07010022 2/27/2008 13:24 D No 10 U Upper RDP 07010022 3/11/2008 12:12 D No 10 U Upper RDP 07010022 4/8/2008 12:33 W No 72 Upper RDP 07010022 6/3/2008 15:27 W No 7270 Upper RDP 07010022 7/17/2008 12:00 D No 190 Upper RDP 07010022 8/14/2008 12:06 D No 120 Upper RDP 07010022 8/28/2008 11:18 W No 580 Upper RDP 07010022 9/4/2008 6:16 W No 23000 Upper RDP 07010022 9/25/2008 12:25 D No 1080 X Upper RDP 07010022 10/14/2008 11:37 D No 108000 X Upper RDP 07010022 10/22/2008 11:53 D No 2500 Upper RDP SITE 8 10/12/2004 23:59 W S No 2000 Upper RDP SITE 8 12/7/2004 23:59 W S No 3300 Upper RDP SITE 8 1/4/2005 12:14 W S No 21000 1,521 1,532 Y Y Y Y 7,890 2,095 Upper RDP SITE 8 1/4/2005 12:14 W S No 21000 Upper RDP SITE 8 6/9/2005 12:41 W S No 820 Upper RDP SITE 8 7/12/2005 23:59 W S No 2100 Upper RDP SITE 8 11/15/2005 23:59 W S No 5200 Upper RDP SITE 8 5/2/2006 0:00 W S No 3200 Upper RDP SITE 8 10/17/2006 0:00 W S No 200 Upper RDP SITE 8 4/11/2007 0:00 W S No 1400 Upper RDP SITE 8 5/2/2007 0:00 W S No 2100 Upper RDP SITE 8 10/3/2007 0:00 W S No 5800 Upper RDP SITE 8 12/10/2007 0:00 W S No 9100 Upper RDP SITE 8 2/5/2008 23:59 W No 690 Upper RDP SITE 8 3/3/2008 23:59 W No 1100 * Bold text indicates concentrations used in calculation of geometric mean ** Geometric mean concentrations calculated from April 1 to October 31, for seasons with 5 or more data points This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX D Wet Weather Survey Sampling Results This page is blank to facilitate double-sided printing. D-1 Table D-1 October 2007 Field and Laboratory Monitoring Results Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (°F) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Collectors Sample Desc. Temp. (°C) Specific Cond. (µS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Comments and Visual Observations 60 LRdP-6 10/3/07 2:45 0-6 62 Heavy Light Y RM/JF 22.3 277 6.3 6.5 Brown None N Y None Riffles in river 58 LRdP-4 10/3/07 3:40 0-6 61 Heavy Light Y RM/JF 21.5 221 4.2 6.6 Brown Y N None Trash, Trees 59 LRdP-5 10/3/07 3:20 0-6 63 Heavy Light Y RM/JF 21.7 276 5.9 6.6 Brown None N N None 57 LRdP-3 10/3/07 4:00 0-6 60 Heavy Light Y RM/JF 21.6 187 3.7 7.1 Brown None N N None 56 LRdP-2 10/3/07 4:15 0-6 60 Heavy Light Y RM/JF 21.7 180 3.3 7.1 Brown None Y N Sticks/Twigs 55 LRdP-1 10/3/07 4:35 0-6 60 Heavy Medium Y RM/JF 21.9 208 3.2 7.2 Brown None Y N Trees 54 LRdP-6 10/3/07 11:45 12 70 None None Y RM/JF 26.6 927 8.4 7.6 None None N N Light Algal Growth submerged 53 FB 10/3/07 11:45 12 70 None None Y RM/JF Field Blank Field Blank 49 LRdP-4 10/3/07 12:45 12 75 None None Y RM/JF 24.0 374 3.6 8.8 Brown None N N None High Sediment. Vegetation in stream bed. Tire tracks in stream. 52 LRdP-5 10/3/07 12:20 12 72 None None Y RM/JF 22.4 591 4.4 9.3 None None N N Light Entered stream, sample collected in center of channel. 51 LRdP-3 10/3/07 13:05 12 75 None None Y RM/JF 24.2 379 3.6 9.7 None None N N None Suspended solids 50 LRdP-2 10/3/07 13:20 12 78 None None Y RM/JF 24.0 376 2.8 9.5 None None N N None Vegetation in channel. 48 LRdP-1 10/3/07 13:35 12 75 None None Y RM/JF 23.9 339 3.0 7.9 None None N N None 47 URdP-3 10/3/07 23:15 24 65 None None Y RM/JF 21.0 419 9.0 6.9 None None N N None 45 URdP-2 10/3/07 23:30 24 65 None None Y RM/JF 20.6 398 5.3 6.7 None None N N None 46 URdP-1 10/3/07 23:47 24 65 None None Y RM/JF 19.9 343 4.8 7.0 None None N N None 44 LRdP-6 10/4/07 0:15 24 65 None None Y RM/JF 19.2 1,511 3.5 7.3 None None N N Light Algal Growth submerged 43 LRdP-5 10/4/07 0:30 24 60 None None Y RM/JF 21.7 676 3.0 9.8 None None N N Light Algal Growth submerged 42 LRdP-4 10/4/07 0:50 24 65 None None Y RM/JF 19.6 350 4.1 7.9 None None N N None 41 LRdP-3 10/4/07 1:05 24 65 None None Y RM/JF 21.2 400 4.3 7.6 None None N N None 39 LRdP-2 10/4/07 1:35 24 62 None None Y RM/JF 21.5 381 3.8 7.6 None None N N None 37 LRdP-1 10/4/07 1:20 24 64 None None Y RM/JF 21.5 264 4.7 7.6 None None N N None 36 MCr-1 10/4/07 2:15 24 65 None None Y RM/JF 20.4 365 5.6 7.5 None None N N None 40 MCr-2 10/4/07 2:22 24 63 None None Y RM/JF 21.2 349 3.7 7.5 Brown None N N None 38 MCr-3 10/4/07 2:40 24 63 None None Y RM/JF 21.0 298 3.7 7.6 Brown None N N None 22 URdP-3 10/4/07 22:30 48 65 None None N RM/JF 22.1 526 3.5 8.4 None None N N None 21 URdP-3 10/4/07 22:30 48 65 None None N RM/JF Dup. of 22 Duplicate URdP-1 10/4/07 23:00 48 65 None None N RM/JF Dry No Sample - Stream Dry 34 URdP-2 10/4/07 22:50 48 65 None None N RM/JF 22.0 469 3.4 8.5 None None N N None 23 FB 10/4/07 22:50 48 65 None None N RM/JF Field Blank Field Blank 33 LRdP-6 10/4/07 23:20 48 65 None None N RM/JF 22.7 1,624 3.7 8.2 None None N N Light Algal Growth submerged LRdP-5 10/4/07 23:45 48 70 None None N RM/JF Dry No Sample - Stream Dry 35 LRdP-4 10/5/07 0:00 48 75 None None N RM/JF 23.6 559 3.5 8.4 None None N N None 30 LRdP-3 10/5/07 0:20 48 72 None None N RM/JF 24.4 485 3.5 8.5 None None N N None 31 LRdP-2 10/5/07 0:40 48 70 None None N RM/JF 24.6 495 3.2 8.4 None None N N None 29 LRdP-2 10/5/07 0:40 48 70 None None N RM/JF Dup. of 31 Duplicate 24 LRdP-1 10/5/07 0:55 48 None None N RM/JF 23.7 434 2.6 8.5 None None N N None 25 MCr-1 10/5/07 1:30 48 65 None None N RM/JF 23.3 379 4.6 8.5 None None N N None 27 MCr-2 10/5/07 1:45 48 65 None None N RM/JF 22.2 339 2.7 8.3 None None N N None 32 MCr-3 10/5/07 2:00 48 65 None None N RM/JF 22.1 318 3.0 8.0 None None N N None 61 MCr-3 10/3/07 2:30 0-6 67 Heavy Light Y CL/JH 22.4 281 7.5 6.7 Brown None Y N None Floating Woody debris 62 MCr-2 10/3/07 2:50 0-6 67 Heavy Light Y CL/JH 22.2 343 7.3 6.6 Brown None Y N None Floating Trash 63 MCr-1 10/3/07 3:10 0-6 67 Heavy Light Y CL/JH 22.0 332 7.6 6.7 Brown Sewage Y N None Trash & Woody Floating Debris 64 URdP-2 10/3/07 4:00 0-6 68 Heavy Light Y CL/JH 21.2 270 7.4 6.7 Brown None N N None 65 URdP-1 10/3/07 4:10 0-6 68 Heavy Light Y CL/JH 21.5 212 7.8 6.8 Brown None N N None 66 URdP-3 10/3/07 4:30 0-6 68 Heavy Light Y CL/JH 21.2 241 7.6 6.9 Brown None N N None 67 MCr-3 10/3/07 11:25 12 70 None None Y CL/JH 21.7 351 7.4 6.7 Brown None N N None 68 MCr-2 10/3/07 11:45 12 70 None None Y CL/JH 22.5 394 6.8 6.7 Brown None N Y None Woody Buried debris 69 MCr-1 10/3/07 11:55 12 70 None None Y CL/JH 23.3 402 7.1 6.7 Brown None N N None 70 URdP-2 10/3/07 12:35 12 70 None None Y CL/JH 24.7 315 9.1 7.0 Brown None N N None 71 URdP-2 10/3/07 12:35 12 70 None None Y CL/JH Dup. of 70 Duplicate 72 URdP-3 10/3/07 12:55 12 70 None None Y CL/JH 21.9 381 7.7 6.9 Brown None Y Y None Floating & buried trash 73 URdP-1 10/3/07 13:25 12 70 None None Y CL/JH 22.8 359 6.1 6.9 Brown None N N None D-2 Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (°F) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Collectors Sample Desc. Temp. (°C) Specific Cond. (µS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Comments and Visual Observations 74 URdP-1 10/3/07 13:25 12 70 None None Y CL/JH Dup. of 73 Duplicate 83 MCr-3 10/6/07 4:35 72 75 None None N NM/JF 22.9 356 4.5 7.3 None None N N None 84 MCr-2 10/6/07 4:17 72 75 None None N NM/JF 23.0 360 4.6 7.3 None None N N None 85 MCr-1 10/6/07 3:55 72 75 None None N NM/JF 23.7 392 6.1 7.1 None None N N None 28 URdP-3 10/6/07 0:55 72 75 None None N NM/JF 23.6 527 3.1 6.5 None None N N None 26 URdP-2 10/6/07 1:20 72 75 None None N NM/JF 23.0 542 2.5 7.2 None None N N None URdP-1 10/6/07 1:25 72 75 None None N NM/JF Dry No Sample - Stream Dry 76 LRdP-6 10/6/07 1:45 72 75 None None N NM/JF 27.7 1,676 6.2 7.6 None None N N None 77 LRdP-6 10/6/07 1:45 72 75 None None N NM/JF Dup. of 76 Duplicate LRdP-5 10/6/07 1:55 72 75 None None N NM/JF Dry No Sample - Stream Dry 75 LRdP-4 10/6/07 2:15 72 75 None None N NM/JF 23.7 675 5.1 7.3 None None N N None 78 LRdP-3 10/6/07 2:30 72 75 None None N NM/JF 24.2 562 5.6 7.3 None None N N None 81 LRdP-2 10/6/07 2:55 72 75 None None N NM/JF 25.3 541 5.3 7.4 None Earthy N N None 82 LRdP-2 10/6/07 2:55 72 75 None None N NM/JF Dup. of 81 Duplicate 80 LRdP-1 10/6/07 3:20 72 75 None None N NM/JF 24.3 474 3.2 7.3 None None N N None 79 FB 10/6/07 3:20 72 75 None None N NM/JF Field Blank Field Blank D-3 Figure D-1 October 2007 dissolved oxygen monitoring results for Lower River Des Peres sampling sites Figure D-2 October 2007 dissolved oxygen monitoring results for Maline Creek sampling sites Figure D-3 October 2007 dissolved oxygen monitoring results for Upper River Des Peres sampling sites D-4 Figure D-4 October 2007 E. coli monitoring results for Lower River Des Peres sampling sites Figure D-5 October 2007 E. coli monitoring results for Maline Creek sampling sites Figure D-6 October 2007 E. coli monitoring results for Upper River Des Peres sampling sites D-5 Figure D-7 October 2007 CBOD monitoring results for Upper River Des Peres sampling sites Figure D-8 October 2007 CBOD monitoring results for Maline Creek sampling sites Figure D-9 October 2007 CBOD monitoring results for Upper River Des Peres sampling sites D-6 Figure D-10 October 2007 TKN monitoring results for Lower River Des Peres sampling sites Figure D-11 October 2007 TKN monitoring results for Maline Creek sampling sites Figure D-12 October 2007 TKN monitoring results for Upper River Des Peres sampling sites D-7 Figure D-13 October 2007 organic nitrogen monitoring results for Lower River Des Peres sampling sites Figure D-14 October 2007 organic nitrogen monitoring results for Maline Creek sampling sites Figure D-15 October 2007 organic nitrogen monitoring results for Upper River Des Peres sampling sites D-8 Figure D-16 October 2007 nitrate-nitrite monitoring results for Lower River Des Peres sampling sites Figure D-17 October 2007 nitrate-nitrite monitoring results for Maline Creek sampling sites Figure D-18 October 2007 nitrate-nitrite monitoring results for Upper River Des Peres sampling sites D-9 Figure D-19 October 2007 ammonia monitoring results for Lower River Des Peres sampling sites Figure D-20 October 2007 ammonia monitoring results for Maline Creek sampling sites Figure D-21 October 2007 ammonia monitoring results for the Upper River Des Peres sampling sites D-10 Figure D-22 October 2007 conductivity monitoring results for Lower River Des Peres sampling sites Figure D-23 October 2007 conductivity monitoring results for Maline Creek sampling sites Figure D-24 October 2007 conductivity monitoring results for Upper River Des Peres sampling sites D-11 Table D-2 November 2007 Field and Laboratory Monitoring Results Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (F) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Collectors Sample Descriptions Temp. (C) Specific Cond. (uS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Photos? Comments and Visual Observations 2 URdP-3 11/13/2007 2:30 PM 24 60 Medium None Y RM/JH 15.5 353.1 7.27 6.71 Colorless None N N None N 3 URdP-3 11/13/2007 2:35 PM 24 60 Medium None Y RM/JH Duplicate duplicate collected of 2 4 LRdP-6 11/13/2007 3:05 PM 24 60 Medium None Y RM/JH 18 725 4.1 6.69 Colorless None N N Heavy N Heavy submerged algal growth 5 LRdP-6 11/13/2007 3:05 PM 24 60 Medium None Y RM/JH Duplicate Heavy submerged algal growth 6 LRdP-5 11/13/2007 3:30 PM 24 60 Medium None Y RM/JH 18 617 3.19 6.65 Colorless None N N Light N light submerged algal growth 7 LRdP-4 11/13/2007 3:45 PM 24 60 Heavy None Y RM/JH 17.3 507.4 4.35 6.71 Colorless None N N None N 8 LRdP-3 11/13/2007 4:00 PM 24 60 Heavy None Y RM/JH 17.3 461.5 3.3 6.65 Colorless None N N None N 9 LRdP-2 11/13/2007 4:15 PM 24 60 Heavy None Y RM/JH 17.3 449 3.21 6.73 Colorless None N N None N 10 LRdP-1 11/13/2007 4:30 PM 24 55 Heavy None Y RM/JH 16.5 389.5 2.78 6.87 Colorless None N N None N 11 MCr-1 11/13/2007 5:10 PM 24 55 Heavy None Y RM/JH 15.4 517 4.18 6.68 Colorless None N N None N 12 MCr-2 11/13/2007 5:30 PM 24 55 Medium None Y RM/JH 14.3 568 2.8 6.77 Colorless None N N None N 13 MCr-3 11/13/2007 5:40 PM 24 55 Medium None Y RM/JH 14.4 615 2.5 6.74 Colorless None N N None N 14 MCr-3 11/13/2007 5:40 PM 24 55 Medium None Y RM/JH Field Blank Field blank collected 15 URdP-1 11/14/2007 1:35 PM 48 55 Heavy None N RM/TA 14.5 345.6 5.49 6.91 Colorless None N N None N 16 URdP-3 11/14/2007 1:54 PM 48 55 Heavy None N RM/TA 14.1 426.7 6.09 7.07 Colorless None N N None N 17 URdP-3 11/14/2007 1:54 PM 48 55 Heavy None N RM/TA Duplicate Field duplicate collected of 16 18 LRdP-6 11/14/2007 2:25 PM 48 55 Heavy None N RM/TA 15.5 611 3.3 7.01 Colorless None N N Light N light submerged algal growth 19 LRdP-5 11/14/2007 2:53 PM 48 55 Heavy None N RM/TA 13.8 769 4.4 7.08 Colorless None N N Light N light submerged algal growth 20 LRdP-4 11/14/2007 3:10 PM 48 55 Heavy None N RM/TA 15 450.7 7.49 7.41 Brown None N N None N with brown tint 86 LRdP-6 11/12/2007 5:10 PM 0-6 55 Heavy Light Y RM/TA 18.4 220 4.82 7.3 Brown None N N None N 87 LRdP-5 11/12/2007 5:35 PM 0-6 55 Heavy None Y RM/TA 18 233.3 5.32 7.02 Brown None N N None N 88 LRdP-4 11/12/2007 6:00 PM 0-6 55 Heavy None Y RM/TA 16.8 300 5.17 7.26 Brown None N N None N 89 LRdP-3 11/12/2007 6:20 PM 0-6 55 Heavy None Y RM/TA 17.5 200 2.25 7.37 Brown None N N None N 90 LRdP-2 11/12/2007 6:30 PM 0-6 55 Heavy None Y RM/TA 17.5 200 1.95 7.37 Brown None Y N None N Trash/leafy debris 91 LRdP-1 11/12/2007 6:50 PM 0-6 55 Heavy Light Y RM/TA 16.8 300 1.63 7.35 Brown None N N None N 92 URdP-2 11/13/2007 2:03 PM 24 60 Medium None Y RM/JH 17.3 332.6 9.36 6.93 Brown None N Y None N trash buried debris 93 URdP-1 11/13/2007 2:25 PM 24 60 Medium None Y RM/JH 16.1 294 6.33 6.71 Colorless None N N None N 94 MCr-3 11/12/2007 4:47 PM 0-6 60 Medium None Y CL/JV 13.7 691 11.3 6.93 Brown None Y N None N Leafy debris 95 MCr-2 11/12/2007 5:01 PM 0-6 60 Medium Light Y CL/JV 12.7 646 11.1 7.08 Brown None Y N None N Leafy debris 96 MCr-1 11/12/2007 5:19 PM 0-6 58 Medium Light Y CL/JV 12.4 651 11.3 7.46 Brown None Y N None N Leafy debris 97 URdP-2 11/12/2007 6:00 PM 0-6 55 Medium None Y CL/JV 16 259 8.13 7.49 Brown Earthy Y N None N Trash debris 99 URdP-1 11/12/2007 6:15 PM 0-6 55 Medium None Y CL/JV 16.6 214 8.7 7.6 Other None N N None N Color light brown 101 URdP-3 11/12/2007 6:32 PM 0-6 55 Medium None Y CL/JV 16.5 262 8.68 7.63 Other None N N None N Color light brown 102 LRdP-1 11/13/2007 1:31 AM 12 50 Medium Light Y JV/TA 14.8 336.5 5.47 7.47 Other None N N None N Color light brown 103 LRdP-1 11/13/2007 1:31 AM 12 50 Medium Light Y JV/TA Duplicate Color light brown, duplicate collected of 102 104 LRdP-2 11/13/2007 1:58 AM 12 50 Medium Light Y JV/TA 15 413.6 2.44 7.49 Other None N N None N Color light brown 105 LRdP-3 11/13/2007 2:16 AM 12 50 Medium Light Y JV/TA 14.8 451 2.62 7.42 Other None N N None N Color light brown 106 LRdP-4 11/13/2007 2:44 AM 12 50 Medium None Y JV/TA 14.7 504 3.2 7.59 Other None N N None N Color light brown 108 LRdP-5 11/13/2007 3:07 AM 12 50 Medium None Y JV/TA 15.7 259.7 3.59 7.68 Other None N N None N Color light brown 109 LRdP-6 11/13/2007 3:39 AM 12 50 Medium None Y JV/TA 16.2 571 2.97 7.75 Other None N N None N Color light brown 110 URdP-2 11/13/2007 4:30 AM 12 50 Medium None Y JV/TA 13.2 433.6 5.46 7.86 Brown None N N None N 111 URdP-2 11/13/2007 4:30 AM 12 50 Medium None Y JV/TA Field Blank Color light brown, field blank collected 112 URdP-1 11/13/2007 4:58 AM 12 50 Medium None Y JV/TA 14.3 333.5 3.87 7.81 Other None N N None N Color light brown 113 URdP-3 11/13/2007 5:15 AM 12 50 Medium None Y JV/TA 13.8 392.8 4.85 7.79 Other None N N None N Color light brown 114 MCr-3 11/13/2007 5:48 AM 12 55 Medium None Y JV/TA 13.4 815 5.56 7.78 Other None N N None N Color light brown 115 MCr-2 11/13/2007 6:06 AM 12 55 Medium None Y JV/TA 13 634 4.33 7.77 Other None N N None N Color light brown 116 MCr-2 11/13/2007 6:06 AM 12 55 Medium None Y JV/TA 13 634 4.33 7.77 Other None N N None N Color light brown, field duplicate collected of 115 117 MCr-1 11/13/2007 6:24 AM 12 55 Light None Y JV/TA 12.9 446.3 3.99 7.8 Other None N N None N Color light brown 118 LRdP-3 11/14/2007 3:30 PM 48 55 Heavy None N RM/TA 13.8 450.9 4.74 7.15 Other None N N None N Brown tint but clean D-12 Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (F) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Collectors Sample Descriptions Temp. (C) Specific Cond. (uS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Photos? Comments and Visual Observations 119 LRdP-2 11/14/2007 3:45 PM 48 55 Heavy None N RM/TA 14.1 494.9 7.04 7.12 Colorless None N N Light N light submerged algal growth 120 LRdP-1 11/14/2007 4:00 PM 48 55 Heavy None N RM/TA 14 404.3 6.11 7.01 Colorless None N N None N 121 MCr-1 11/14/2007 4:30 PM 48 50 Heavy None N RM/TA 12.5 533 4.52 7.09 Colorless None N N Light N light submerged algal growth 122 MCr-2 11/14/2007 4:50 PM 48 50 Heavy None N RM/TA 14.4 584 1.65 7 Other None N N Medium N Medium submerged algal growth, color: brown tint but clean 123 MCr-3 11/14/2007 5:05 PM 48 50 Heavy None N RM/TA 13.2 599 2.27 7.08 Other None N N None N Brown tint but clean 124 MCr-3 11/14/2007 5:05 PM 48 50 Heavy None N RM/TA Field Blank Field blank collected 125 LRdP-6 11/15/2007 1:20 PM 72 50 None None N JV/JH 11.1 429.1 7.93 7.15 Colorless None N N Light N light submerged algal growth 126 LRdP-5 11/15/2007 1:40 PM 72 50 None None N JV/JH 10.2 452.9 6.46 6.98 Colorless None N N Light N light submerged algal growth 127 LRdP-4 11/15/2007 1:50 PM 72 50 None None N JV/JH 11.4 426 5.68 7.26 Colorless None N N Medium N Medium submerged algal growth 128 LRdP-3 11/15/2007 2:10 PM 72 50 None None N JV/JH 11.9 424.1 9.51 7.76 Colorless None N N Light N light submerged algal growth 129 LRdP-2 11/15/2007 2:25 PM 72 50 None None N JV/JH 10 715 5.2 7.5 Colorless None N Y Light N light submerged algal growth, buried leaf mats 130 LRdP-2 11/15/2007 2:25 PM 72 50 None None N JV/JH Duplicate duplicate collected of 129 131 LRdP-1 11/15/2007 2:52 PM 72 50 None None N JV/JH 8.5 752 6.29 7.62 Colorless None N N Light N Light submerged algal growth, pipe discharge at bridge, low flow conditions 132 URdP-1 11/15/2007 3:45 PM 72 50 None None N JV/JH 8.7 346.6 2.36 7.14 Other None Y Y None N Color light brown, floating leaf mat debris, buried woody debris, pool-like (little flow) condition 133 URdP3 11/15/2007 4:00 PM 72 50 None None N JV/JH 8.9 432 5.57 7.1 Colorless None N N Light N light submerged algal growth, water flowing 134 MCr-3 11/15/2007 4:30 PM 72 50 None None N JV/JH 8.7 725 2.86 7.19 Other None Y N Medium N Medium submerged algal growth, color: light brown 135 MCr-2 11/15/2007 4:45 PM 72 50 None None N JV/JH 11 811 1.3 7.24 Colorless None Y N Heavy N Heavy submerged algal growth, floating leafmat debris 136 MCr-1 11/15/2007 5:00 PM 72 50 None None N JV/JH 10 563 3.71 7.38 Colorless None N N Light N light submerged algal growth URdP-2 11/14/2007 1:30 PM 48 55 Heavy None N RM/TA Dry N No water flowing, no sample to collect URdP-2 11/15/2007 3:40 PM 72 50 None None N JV/JH Dry D-13 Figure D-25 November 2007 dissolved oxygen monitoring results for Lower River Des Peres sampling sites Figure D-26 November 2007 dissolved oxygen monitoring results for Maline Creek sampling sites Figure D-27 November 2007 dissolved oxygen monitoring results for Upper River Des Peres sampling sites D-14 Figure D-28 November 2007 E. coli monitoring results for Lower River Des Peres sampling sites Figure D-29 November 2007 E. coli monitoring results for Maline Creek sampling sites Figure D-30 November 2007 E. coli monitoring results for Upper River Des Peres sampling sites D-15 Figure D-31 November 2007 CBOD monitoring results for Lower River Des Peres sampling sites Figure D-32 November 2007 CBOD monitoring results for Maline Creek sampling sites Figure D-33 November 2007 CBOD monitoring results for Upper River Des Peres sampling sites D-16 Figure D-34 November 2007 TKN monitoring results for Lower River Des Peres sampling sites Figure D-35 November 2007 TKN monitoring results for Maline Creek sampling sites Figure D-36 November 2007 TKN monitoring results for Upper River Des Peres sampling sites D-17 Figure D-37 November 2007 organic nitrogen monitoring results for Lower River Des Peres sampling sites Figure D-38 November 2007 organic nitrogen monitoring results for Maline Creek sampling sites Figure D-39 November 2007 organic nitrogen monitoring results for Upper River Des Peres sampling sites D-18 Figure D-40 November 2007 nitrate-nitrite nitrogen monitoring results for Lower River Des Peres sampling sites Figure D-41 November 2007 nitrate-nitrite nitrogen monitoring results for Maline Creek sampling sites Figure D-42 November 2007 nitrate-nitrite nitrogen monitoring results for Upper River Des Peres sampling sites D-19 Figure D-43 November 2007 ammonia monitoring results for Lower River Des Peres sampling sites Figure D-44 November 2007 ammonia monitoring results for Maline Creek sampling sites Figure D-45 November 2007 ammonia monitoring results for Upper River Des Peres sampling sites D-20 Figure D-46 November 2007 conductivity monitoring results for Lower River Des Peres sampling sites Figure D-47 November 2007 conductivity monitoring results for Maline Creek sampling sites Figure D-48 November 2007 conductivity monitoring results for Upper River Des Peres sampling sites D-21 Table D-3 June 2008 Field and Laboratory Monitoring Results Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (oF) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Sample Descriptions Temp. (oC) Specific Cond. (uS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Photos? Comments and Visual Observations 147 Hanley1 6/13/2008 12:07 0-06 77 Medium None N Regular 22.03 305 6.50 7.76 Brown Sewage Y N None N grass and leafs floating debris 162 Hanley1 6/13/2008 23:34 12 70 Light None Y Regular 20.51 473 4.88 7.68 Colorless None Y N None N grass floating debris 167 Hanley1 6/14/2008 10:50 24 75 None None Y Regular 22.17 549 6.01 7.69 Brown None N N None N Manhole cover open, water very low-will be dry next sampling event 177 Hanley1 6/15/2008 10:55 48 83 None None N Regular 21.29 717 4.49 7.71 Colorless Sewage N N Medium N 183 Hanley1 6/16/2008 11:25 72 70 Medium None N Regular 21.06 780 4.44 7.7 Colorless Sewage N N Medium N Manhole cover open, water very low-will be dry next sampling event 184 Hanley1 6/16/2008 11:25 72 70 Medium None N Field Blank 190 Hanley1 6/17/2008 11:00 96 70 None None N Regular 19.48 792 4.64 7.78 Colorless Sewage N N Medium N 146 Hanley2 6/13/2008 11:52 0-06 78 Medium Light N Regular 21.98 392 7.39 8.04 Brown Sewage Y N None N grass and leafs floating debris, meters were calibrated here at 8:00 am earlier this morning 161 Hanley2 6/13/2008 23:12 12 70 Light None Y Regular 20.73 488 7.65 8.18 Colorless Sewage Y N None N leafs floating debris N/A Hanley2 6/14/2008 10:35 24 70 None None Y N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A Hanley2 6/15/2008 N/A 48 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A Hanley2 6/16/2008 11:45 72 70 Medium None N N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A Hanley2 6/17/2008 N/A 96 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry 144 Mendell 6/13/2008 11:19 0-06 78 Medium Light N Regular 22.07 454 7.89 9.86 Brown None Y N Light N grass and leafs floating debris 145 Mendell 6/13/2008 11:19 0-06 78 Medium Light N Field Blank 160 Mendell 6/13/2008 22:50 12 70 Light None Y Regular 19.93 768 7.60 8.13 Colorless None N N Light N 168 Mendell 6/14/2008 11:15 24 75 None None Y Regular 28.15 606 12.54 9.09 Colorless None N N light N water very low-most likely will be dry by next sampling event 175 Mendell 6/15/2008 10:25 48 80 None None N Regular 25.00 983 13.61 9.24 Colorless None N N Heavy N 176 Mendell 6/15/2008 10:25 48 80 None None N Field Blank 182 Mendell 6/16/2008 11:00 72 70 Light None N Regular 23.49 1075 16.81 9.28 Colorless None N N Heavy N water was very low 189 Mendell 6/17/2008 10:35 96 70 None None N Regular 22.39 1137 12.83 9.1 Colorless None N N Heavy N very low flow 143 URdP-1 6/13/2008 11:00 0-06 78 Heavy Heavy N Regular 23.24 929 5.63 7.68 Brown None Y N None N grass and leafs floating debris 158 URdP-1 6/13/2008 22:40 12 70 Light None Y Regular 22.22 848 4.78 7.62 Brown Sewage Y N None N leafs floating debris 159 URdP-1 6/13/2008 22:40 12 70 Light None Y Field Blank N/A URdP-1 6/14/2008 11:40 24 80 None None Y N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A URdP-1 6/15/2008 N/A 48 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A URdP-1 6/16/2008 10:55 72 70 Light None N N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry N/A URdP-1 6/17/2008 N/A 96 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Dry 151 URdP-2 6/13/2008 13:07 0-06 73 Light Light N Regular 22.89 417 6.74 8.85 Brown Sewage Y N None N grass and leafs floating debris, foam on water surface 166 URdP-2 6/14/2008 0:28 12 68 None None Y Regular 21.58 748 5.86 7.93 Colorless Sewage Y N None N leafs floating debris 169 URdP-2 6/14/2008 11:50 24 80 None None Y Regular 23.92 850 7.01 7.89 Colorless None N N None N 170 URdP-2 6/14/2008 11:50 24 80 None None Y Duplicate 173 URdP-2 6/14/2008 12:20 24 80 None None Y Regular 25.50 818 6.72 7.72 Colorless Sewage N N Light N 180 URdP-2 6/15/2008 11:43 48 85 None None N Regular 25.11 953 6.33 7.89 Colorless None N N Medium N 181 URdP-2 6/15/2008 11:43 48 85 None None N Duplicate 188 URdP-2 6/16/2008 12:20 72 75 Light None N Regular 24.09 992 7.32 7.86 Colorless None N N Medium N 195 URdP-2 6/17/2008 11:40 96 75 None None N Regular 22.63 1047 7.76 7.93 Colorless None N N Light N 150 URdP-3 6/13/2008 12:42 0-06 76 Medium None N Regular 23.13 336 7.04 8.80 Brown Sewage Y N Light N grass and leafs floating debris 164 URdP-3 6/14/2008 0:07 12 70 None None Y Regular 21.41 711 6.30 7.92 Colorless Sewage Y N Light N leafs floating debris 165 URdP-3 6/14/2008 0:07 12 70 None None Y Duplicate 171 URdP-3 6/14/2008 12:10 24 80 None None Y Blank 172 URdP-3 6/14/2008 12:10 24 80 None None Y Regular 26.58 793 11.32 8.71 Colorless Sewage N N Light N 179 URdP-3 6/15/2008 11:30 48 84 None None N Regular 25.34 940 10.30 8.51 Colorless Sewage N N Light N 186 URdP-3 6/16/2008 12:05 72 75 Light None N Regular 23.00 1001 8.99 8.14 Colorless Sewage N N Light N 187 URdP-3 6/16/2008 12:05 72 75 Light None N Duplicate 193 URdP-3 6/17/2008 11:25 96 75 None None N Regular 21.52 1021 11.45 8.52 Colorless Sewage N N Light N 194 URdP-3 6/17/2008 11:25 96 75 None None N Field Blank 148 URdP-4 6/13/2008 12:29 0-06 75 Medium None N Regular 23.18 352 5.95 7.79 Brown Sewage Y N Light N grass and leafs floating dedris 149 URdP-4 6/13/2008 12:29 0-06 75 Medium None N Duplicate 163 URdP-4 6/13/2008 23:54 12 70 Light None Y Regular 21.71 653 4.41 7.66 Colorless None Y N Light N leafs floating debris 178 URdP-4 6/15/2008 11:15 48 83 None None N Regular 24.97 961 4.38 7.62 Colorless Sewage N N Medium N 185 URdP-4 6/16/2008 11:50 72 70 Medium None N Regular 25.13 952 5.46 7.64 Colorless None N N Medium N 191 URdP-4 6/17/2008 11:10 96 75 None None N Regular 23.54 1031 5.88 7.64 Colorless Sewage N N Heavy N 192 URdP-4 6/17/2008 11:10 96 75 None None N Duplicate D-22 This page is blank to facilitate double-sided printing. D-23 Figure D-49 June 2008 dissolved oxygen monitoring results for Upper River Des Peres tributary sampling sites Figure D-50 June 2008 dissolved oxygen monitoring results for Upper River Des Peres sampling sites Figure D-51 June 2008 E. coli monitoring results for Upper River Des Peres tributary sampling sites D-24 Figure D-52 June 2008 E. coli monitoring results for Upper River Des Peres sampling sites Figure D-53 June 2008 CBOD monitoring results for Upper River Des Peres tributary sampling sites Figure D-54 June 2008 CBOD monitoring results for Upper River Des Peres sampling sites D-25 Figure D-55 June 2008 TKN monitoring results for Upper River Des Peres tributary sampling sites Figure D-56 June 2008 TKN monitoring results for Upper River Des Peres sampling sites Figure D-57 June 2008 organic nitrogen monitoring results for Upper River Des Peres tributary sampling sites D-26 Figure D-58 June 2008 organic nitrogen monitoring results for Upper River Des Peres sampling sites Figure D-59 June 2008 nitrate nitrogen monitoring results for Upper River Des Peres tributary sampling sites Figure D-60 June 2008 nitrate nitrogen monitoring results for Upper River Des Peres sampling sites D-27 Figure D-61 June 2008 ammonia monitoring results for Upper River Des Peres tributary sampling sites Figure D-62 June 2008 ammonia monitoring results for Upper River Des Peres sampling sites Figure D-63 June 2008 conductivity monitoring results for Upper River Des Peres tributary sampling sites D-28 Figure D-64 June 2008 conductivity monitoring results for Upper River Des Peres sampling sites D-29 Table D-4 September 2008 Field and Laboratory Monitoring Results Sample Number Sample Site Date Time Sampling Period (hr) Approx. Ambient Temp (°F) Cloud Cover Current Precipitation? Precip. in last 24 hrs? Collectors Sample Descriptions Temp. (°C) Specific Cond. (µS/cm) DO (mg/L) pH (S.U.) Color Odor Floating Debris Buried Debris Algal Growth Photos? Comments and Visual Observations 197 Hanley1 9/4/2008 9:05 0-6 65 Heavy Heavy Y RM, JH 20.58 141 8.03 7.17 brown none woody debris N N tree fell into stream, could not tell algal growth 198 Duplicate 9/4/2008 9:05 0-6 65 Heavy Heavy Y RM, JH Duplicate 20.58 141 8.03 7.17 brown none woody debris N N tree fell into stream, could not tell algal growth 196 Field Blank 9/4/2008 9:40 0-6 65 Heavy Heavy Y RM, JH Field Blank N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 199 URdP-4 9/4/2008 9:40 0-6 65 Heavy Heavy Y RM, JH 20.72 137 8.07 7.71 brown none woody debris N N could not tell algal growth 200 Hanley2 9/4/2008 9:55 0-6 65 Heavy Heavy Y RM, JH 20.34 174 8.06 7.65 brown none woody debris N N could not tell algal growth 201 URdP-2 9/4/2008 10:10 0-6 65 Heavy Heavy Y RM, JH 20.1 136 8.02 8.61 brown none woody debris N N could not tell algal growth 202 URdP-3 9/4/2008 10:20 0-6 65 Heavy Medium Y RM, JH 20.13 129 8.1 8.35 brown none woody debris N N could not tell algal growth 203 Mendell 9/4/2008 10:40 0-6 65 Heavy Heavy Y RM, JH 20.3 177 8.53 8.02 brown none woody debris N N could not tell algal growth 204 URdP-1 9/4/2008 10:55 0-6 65 Heavy Medium Y RM, JH 20.19 186 8.49 8.1 brown none woody debris N N could not tell algal growth 205 Hanley1 9/4/2008 19:00 12 60 Heavy Light Y RM, JH 20.46 243 7.8 8.07 brown none N N None N 206 Hanley2 9/4/2008 19:15 12 60 Heavy Light Y RM, JH 20.64 274 7.68 7.88 brown sewage N N None N 207 URdP-4 9/4/2008 19:25 12 60 Heavy None Y RM, JH 20.81 265 7.88 8.12 colorless none N N None N 208 URdP-3 9/4/2008 19:33 12 60 Heavy None Y RM, JH 20.59 230 7.91 8.17 colorless none N N None N 209 URdP-2 9/4/2008 19:43 12 60 Heavy Light Y RM, JH 20.55 252 7.85 8.18 colorless none N N None N 210 Mendell 9/4/2008 19:58 12 60 Heavy None Y RM, JH 21.17 408 8.1 8.16 colorless none N N None N 211 URdP-1 9/4/2008 20:12 12 60 Heavy None Y RM, JH 20.55 504 8.20 8.25 colorless none N N None N 212 URdP-1 9/5/2008 8:30 24 68 Heavy Light Y JV, CL 19.42 765 10.08 8.77 colorless none N N Medium N submerged algal growth 213 Mendell 9/5/2008 8:57 24 70 Medium None Y JV, CL 19.9 592 9.34 8.77 colorless none N N Medium N submerged algal growth 214 Hanley1 9/5/2008 9:07 24 70 Medium None Y JV, CL 19.54 499 7.03 8.16 colorless none N N Light N 215 Hanley2 9/5/2008 9:22 24 72 Medium None Y JV, CL 18.83 500 9.15 8.52 colorless sewage N N None N 216 URdP-4 9/5/2008 9:37 24 72 Medium None Y JV, CL 19.76 556 7.67 8.17 colorless sewage N N Medium N submerged algal growth 217 Duplicate 9/5/2008 9:37 24 72 Medium None Y JV, CL Duplicate 19.76 556 7.67 8.17 colorless sewage N/A N/A N/A N/A 218 URdP-3 9/5/2008 9:53 24 72 Medium None Y JV, CL 19.65 596 9.6 8.58 green sewage N N Light N submerged algal growth 219 Field Blank 9/5/2008 9:53 24 72 Medium None Y JV, CL Field Blank N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 220 URdP-2 9/5/2008 10:13 24 73 Medium None Y JV, CL 19.46 633 8.23 8.37 brown none N N Medium N submerged algal growth 221 URdP-1 9/6/2008 8:50 48 65 Light None N TA, JW 18.38 782 11.47 8.56 colorless none N N Medium N submerged algal growth 222 Mendell 9/6/2008 9:15 48 65 Light None N TA, JW 17.69 817 11.71 8.84 colorless none N N Medium N submerged algal growth 223 Hanley1 9/6/2008 9:35 48 67 Light None N TA, JW 17.64 619 7.27 8.25 colorless none N N Light N submerged algal growth N/A Hanley2 9/6/2008 9:40 48 68 Light None N TA, JW Dry Dry Dry Dry Dry Dry Dry Dry Dry Dry Site Dry 224 URdP-4 9/6/2008 10:00 48 70 Light None N TA, JW 18.32 753 7.74 8.18 colorless none N N Medium N submerged algal growth 225 Duplicate 9/6/2008 10:00 48 70 Light None N TA, JW Duplicate 18.32 753 7.74 8.18 colorless none N N Medium N submerged algal growth 226 URdP-3 9/6/2008 10:15 48 70 Light None N TA, JW 17.85 762 10.68 8.66 colorless sewage N N Light N submerged algal growth 227 Field Blank 9/6/2008 10:15 48 70 Light None N TA, JW Field Blank N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 228 URdP-2 9/6/2008 10:30 48 70 Light None N TA, JW 17.82 799 8.82 8.47 brown none N N Medium N submerged algal growth 229 URdP-1 9/7/2008 8:20 72 60 Heavy Light Y TA, CL 19.17 740 9.63 8.56 colorless none N N Medium N submerged algal growth 230 Mendell 9/7/2008 8:40 72 63 Heavy None Y TA, CL 18.65 924 10.9 8.83 colorless none N N Medium N submerged algal growth 231 Hanley1 9/7/2008 9:00 72 65 Heavy None Y TA, CL 18.57 652 6.58 8.17 colorless none N N Light N submerged algal growth 232 Duplicate 9/7/2008 9:00 72 65 Heavy None Y TA, CL Duplicate 18.57 652 6.58 8.17 colorless none N N Light N submerged algal growth N/A Hanley2 9/7/2008 9:07 72 N/A Heavy None Y TA, CL N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 233 URdP-4 9/7/2008 9:17 72 65 Heavy None Y TA, CL 19.47 856 7.39 8.16 colorless none N N Medium N submerged algal growth 234 URdP-3 9/7/2008 9:30 72 65 Heavy None Y TA, CL 18.89 823 9.72 8.54 colorless sewage N N Light N submerged algal growth 235 URdP-2 9/7/2008 9:50 72 65 Heavy None Y TA, CL 19.55 836 7.53 8.52 colorless none N N Light N submerged algal growth 236 Field Blank 9/7/2008 9:50 72 65 Heavy None Y TA, CL Field Blank N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 239 URdP-1 9/8/2008 8:29 96 70 Medium None N JV, CL 19.99 806 12.76 8.59 colorless none N N Medium N submerged algal growth 240 Duplicate 9/8/2008 8:29 96 70 Mediun None N JV, CL Duplicate 19.99 806 12.76 8.59 colorless none N N Medium N submerged algal growth 241 Mendell 9/8/2008 8:44 96 70 Medium None N JV, CL 18.96 936 12.25 8.75 colorless none N N Heavy N submerged algal growth 242 Field Blank 9/8/2008 8:44 96 70 Medium None N JV, CL Field Blank N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 243 Hanley1 9/8/2008 9:15 96 73 Medium None N JV, CL 18.77 673 6.55 7.95 colorless none N N Light N submerged algal growth N/A Hanley2 9/8/2008 9:23 96 73 Medium None N JV, CL N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 244 URdP-4 9/8/2008 9;28 96 73 Light None N JV, CL 19.7 903 8.65 7.95 colorless none N N Medium N submerged algal growth 246 URdP-3 9/8/2008 9:34 96 73 Light None N JV, CL 18.81 834 8.55 8.38 Grey sewage N N Medium N submerged algal growth, removing bridge, water cloudy, concrete debris falling into the water 247 URdP-2 9/8/2008 9:46 96 75 Light None N JV, CL 19.39 871 8.7 8.16 Colorless none N N Light N submerged algal growth D-30 This page is blank to facilitate double-sided printing. D-31 Figure D-65 September 2008 dissolved oxygen monitoring results for Upper River Des Peres tributary sampling sites Figure D-66 September 2008 dissolved oxygen monitoring results for Upper River Des Peres sampling sites Figure D-67 September 2008 E. coli monitoring results for Upper River Des Peres tributary sampling sites D-32 Figure D-68 September 2008 E. coli monitoring results for Upper River Des Peres sampling sites Figure D-69 September 2008 CBOD monitoring results for Upper River Des Peres tributary sampling sites Figure D-70 September 2008 CBOD monitoring results for Upper River Des Peres sampling sites D-33 Figure D-71 September 2008 TKN monitoring results for Upper River Des Peres tributary sampling sites Figure D-72 September 2008 TKN monitoring results for Upper River Des Peres sampling sites Figure D-73 September 2008 organic nitrogen monitoring results for Upper River Des Peres tributary sampling sites D-34 Figure D-74 September 2008 organic nitrogen monitoring results for Upper River Des Peres sampling sites Figure D-75 September 2008 nitrate nitrogen monitoring results for Upper River Des Peres tributary sampling sites Figure D-76 September 2008 nitrate nitrogen monitoring results for Upper River Des Peres sampling sites D-35 Figure D-77 September 2008 ammonia monitoring results for Upper River Des Peres tributary sampling sites Figure D-78 September 2008 ammonia monitoring results for Upper River Des Peres sampling sites Figure D-79 September 2008 conductivity monitoring results for Upper River Des Peres tributary sampling sites D-36 Figure D-80 September 2008 conductivity monitoring results for Upper River Des Peres sampling sites Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX E Summary of Continuous Monitoring Data This page is blank to facilitate double-sided printing. Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 pH (S.U.)pH 0 5 10 15 20 25 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-1 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 pH (S.U.)pH 0 5 10 15 20 25 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-2 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 pH (S.U.)pH 0 5 10 15 20 25 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-3 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 pH (S.U.)pH 0 5 10 15 20 25 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-4 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 pH (S.U.)pH 0 5 10 15 20 25 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-5 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 pH (S.U.)pH 0 5 10 15 20 25 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-6 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 pH (S.U.)pH 0 5 10 15 20 25 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-7 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 pH (S.U.)pH 0 5 10 15 20 25 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-8 Summary of Sonde Data from LRdP Site 1: Broadway 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-10 Sep-11 Sep-12 Sep-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-10 Sep-11 Sep-12 Sep-13 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-10 Sep-11 Sep-12 Sep-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-10 Sep-11 Sep-12 Sep-13 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-10 Sep-11 Sep-12 Sep-13 pH (S.U.)pH 0 5 10 15 20 25 Sep-10 Sep-11 Sep-12 Sep-13 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-9 Summary of Sonde Data from LRdP Site 2: Morgan Ford Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 pH (S.U.)pH 0 5 10 15 20 25 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Oct-31 Nov-01 Nov-02 Nov-03 Nov-04 Nov-05 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-10 Summary of Sonde Data from LRdP Site 2: Morgan Ford Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 pH (S.U.)pH 0 5 10 15 20 25 Nov-04 Nov-05 Nov-06 Nov-07 Nov-08 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-11 Summary of Sonde Data from LRdP Site 2: Morgan Ford Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-14 Nov-15 Nov-16 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-14 Nov-15 Nov-16 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-14 Nov-15 Nov-16 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-14 Nov-15 Nov-16 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Nov-14 Nov-15 Nov-16 pH (S.U.)pH 0 5 10 15 20 25 Nov-14 Nov-15 Nov-16 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-12 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 pH (S.U.)pH 0 5 10 15 20 25 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Jul-03 Jul-04 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-13 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 pH (S.U.)pH 0 5 10 15 20 25 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Jul-13 Jul-14 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-14 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 pH (S.U.)pH 0 5 10 15 20 25 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Jul-23 Jul-24 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-15 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 pH (S.U.)pH 0 5 10 15 20 25 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Aug-02 Aug-03 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-16 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 pH (S.U.)pH 0 5 10 15 20 25 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-17 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 pH (S.U.)pH 0 5 10 15 20 25 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Aug-23 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-18 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 pH (S.U.)pH 0 5 10 15 20 25 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Sep-01 Sep-02 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-19 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 pH (S.U.)pH 0 5 10 15 20 25 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-07 Sep-08 Sep-09 Sep-10 Sep-11 Sep-12 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-20 Summary of Sonde Data from Maline Creek Site 1: Riverview Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-11 Sep-12 Sep-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-11 Sep-12 Sep-13 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-11 Sep-12 Sep-13 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-11 Sep-12 Sep-13 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-11 Sep-12 Sep-13 pH (S.U.)pH 0 5 10 15 20 25 Sep-11 Sep-12 Sep-13 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-21 Summary of Sonde Data from Maline Creek Site 2: Lewis and Clark Blvd. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 pH (S.U.)pH 0 5 10 15 20 25 Nov-09 Nov-10 Nov-11 Nov-12 Nov-13 Nov-14 Nov-15 Nov-16 Nov-17 Nov-18 Nov-19 Nov-20 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-22 Summary of Sonde Data from Maline Creek Site 2: Lewis and Clark Blvd. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 pH (S.U.)pH 0 5 10 15 20 25 Nov-19 Nov-20 Nov-21 Nov-22 Nov-23 Nov-24 Nov-25 Nov-26 Nov-27 Nov-28 Nov-29 Nov-30 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-23 Summary of Sonde Data from Maline Creek Site 2: Lewis and Clark Blvd. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 pH (S.U.)pH 0 5 10 15 20 25 Nov-29 Nov-30 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-24 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 pH (S.U.)pH 0 5 10 15 20 25 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-25 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 pH (S.U.)pH 0 5 10 15 20 25 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-26 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 pH (S.U.)pH 0 5 10 15 20 25 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-27 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 pH (S.U.)pH 0 5 10 15 20 25 Jun-21 Jun-22 Jun-23 Jun-24 Jun-25 Jun-26 Jun-27 Jun-28 Jun-29 Jun-30 Jul-01 Jul-02 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-28 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 pH (S.U.)pH 0 5 10 15 20 25 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10 Jul-11 Jul-12 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-29 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 pH (S.U.)pH 0 5 10 15 20 25 Jul-11 Jul-12 Jul-13 Jul-14 Jul-15 Jul-16 Jul-17 Jul-18 Jul-19 Jul-20 Jul-21 Jul-22 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-30 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 pH (S.U.)pH 0 5 10 15 20 25 Jul-21 Jul-22 Jul-23 Jul-24 Jul-25 Jul-26 Jul-27 Jul-28 Jul-29 Jul-30 Jul-31 Aug-01 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-31 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 pH (S.U.)pH 0 5 10 15 20 25 Jul-31 Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-32 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 pH (S.U.)pH 0 5 10 15 20 25 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-33 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 pH (S.U.)pH 0 5 10 15 20 25 Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-29 Aug-30 Aug-31 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-34 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 pH (S.U.)pH 0 5 10 15 20 25 Aug-30 Aug-31 Sep-01 Sep-02 Sep-03 Sep-04 Sep-05 Sep-06 Sep-16 Sep-17 Sep-18 Sep-19 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-35 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 pH (S.U.)pH 0 5 10 15 20 25 Sep-16 Sep-17 Sep-18 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-36 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 pH (S.U.)pH 0 5 10 15 20 25 Sep-19 Sep-20 Sep-21 Sep-22 Sep-23 Sep-24 Sep-25 Sep-26 Sep-27 Sep-28 Sep-29 Sep-30 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-37 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 pH (S.U.)pH 0 5 10 15 20 25 Sep-29 Sep-30 Oct-01 Oct-02 Oct-03 Oct-04 Oct-05 Oct-06 Oct-07 Oct-08 Oct-09 Oct-10 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-38 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 pH (S.U.)pH 0 5 10 15 20 25 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Oct-16 Oct-17 Oct-18 Oct-19 Oct-20 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-39 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 pH (S.U.)pH 0 5 10 15 20 25 Oct-19 Oct-20 Oct-21 Oct-22 Oct-23 Oct-24 Oct-25 Oct-26 Oct-27 Oct-28 Oct-29 Oct-30 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-40 Summary of Sonde Data from URdP Site 1: Purdue Avenue 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-29 Oct-30 Oct-31 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-29 Oct-30 Oct-31 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Oct-29 Oct-30 Oct-31 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Oct-29 Oct-30 Oct-31 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Oct-29 Oct-30 Oct-31 pH (S.U.)pH 0 5 10 15 20 25 Oct-29 Oct-30 Oct-31 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-41 Summary of Sonde Data from URdP Site 2: Woodson Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 pH (S.U.)pH 0 5 10 15 20 25 May-22 May-23 May-24 May-25 May-26 May-27 May-28 May-29 May-30 May-31 Jun-01 Jun-02 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-42 Summary of Sonde Data from URdP Site 2: Woodson Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 pH (S.U.)pH 0 5 10 15 20 25 Jun-01 Jun-02 Jun-03 Jun-04 Jun-05 Jun-06 Jun-07 Jun-08 Jun-09 Jun-10 Jun-11 Jun-12 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-43 Summary of Sonde Data from URdP Site 2: Woodson Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 pH (S.U.)pH 0 5 10 15 20 25 Jun-11 Jun-12 Jun-13 Jun-14 Jun-15 Jun-16 Jun-17 Jun-18 Jun-19 Jun-20 Jun-21 Jun-22 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-44 Summary of Sonde Data from URdP Site 2: Woodson Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-21 Jun-22 Jun-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-21 Jun-22 Jun-23 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Jun-21 Jun-22 Jun-23 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Jun-21 Jun-22 Jun-23 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Jun-21 Jun-22 Jun-23 pH (S.U.)pH 0 5 10 15 20 25 Jun-21 Jun-22 Jun-23 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-45 Summary of Sonde Data from URdP Site 3: Pennell Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 pH (S.U.)pH 0 5 10 15 20 25 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug-19 Aug-20 Aug-21 Aug-22 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-46 Summary of Sonde Data from URdP Site 3: Pennell Road 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Conductivity (µS/cm)Conductivity pH 0 0.1 0.2 0.3 0.4 0.5 0.6 0.75 10 15 20 25 30 35 40 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Rainfall (inches)Temperature ( C) Temperature and Rainfall 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Conductivity (µS/cm)Conductivity 4 5 6 7 8 9 10 11 12 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 pH (S.U.)pH 0 5 10 15 20 25 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 DO (mg/L)Dissolved Oxygen Appendix E: Summary of Continuous Monitoring Data E-47 This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX F SWMM5 Model Input Data This page is blank to facilitate double-sided printing.    F‐1 Lower River des Peres SWMM5 Model: Subcatchment Data  Subcatchment Name Outlet Node Area (acres) Impervious Fraction (%) Runoff Width (feet) Slope (%) Impervious Roughness (--) Pervious Roughness (--) Imperv. Storage (in)) Perv. Storage (in) Zero Storage (%) Max. Infiltration Rate (in/hr) Min. Infiltration Rate (in/hr) Decay Constant (1/hr) Drying Time (days) Ballas_N DC_2 497.2 10.8 6581.5 5.83 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Ballas_S DC_2 656.31 8.8 7561.5 5.76 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Black_Cr DC_20 3781.69 14.3 10890.6 6.29 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Black_Es DC_11 65.16 4 2382.5 5.56 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Brentwood DC_18 261.66 17 4774.5 4.95 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Brentwood_I DC_20 40.7 15.3 1883 5.49 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Briarwood DC_6 152.23 12.2 3642 5.84 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Brookside DC_21 100.76 9.8 2963 6.79 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Claytonia_Cr DCa_24 657.89 15.9 7570.5 5.59 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Country_Cs DC_10 655.96 7.4 7559.5 6.5 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Creek_Br DC_8 73.27 13.8 2526.5 3 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Danfield DC_11 31.45 8.3 1655.5 6.27 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Daniel DC_11 126.8 8.8 3323.5 5.93 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 DC-09 DC_6 999.83 9.5 5599.8 7.45 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 DCCP DC_20 154.46 9.1 3668.5 6.54 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 DrCr_Hill DC_10 172.08 4.8 3872 6.68 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 E_WarsonW DC_13 292.27 11.2 5046 6.37 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 German DC_5 47.58 15.5 2036 4.77 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Gold_Dust DC_5 18.01 10.5 1252.5 8.83 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Goldengate DC_14 37.1 8.9 1797.5 6.44 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Greeley_Atl DC_17 167.05 8.3 3815 6 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Hampton_Cr DC_20 1017.01 12.4 5647.8 5.9 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Harty_Park DC_23 129.57 16 3360 7.5 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Lockwood_Cr DC_21 148.18 10.9 3593 6.08 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Lockwood_P DC_22 210.51 14.6 4282.5 6.09 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Mark_Twain DC_19 106.15 11.9 3041 5.01 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Monsanto DC_4 934.39 9.7 5413.5 7.5 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Oxford_Cr DC_22 143.03 21.7 3530 4.91 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Parkridge DC_13 98.54 13.3 2930 4.73 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Plaza_Fron DC_7 273.55 13.6 4881.5 5.63 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Rock_Hill_Cr DC_15 786.01 8.8 4965 6.46 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Russell DC_15 164.98 11.1 3791 4.64 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Shady_Gr DC_17 1674.03 8.3 7245.9 6.04 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 S_Brentwood DC_18 35.54 15.6 1759.5 4.05 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 S_Trib DC_6 531.74 9.8 6806 4.84 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Tilles_P DC_12 136.77 7.2 3452 5.42 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 2Mile_Cr DC_12 4632.95 9.5 12054.3 6.02 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315  F‐2 Subcatchment Name Outlet Node Area (acres) Impervious Fraction (%) Runoff Width (feet) Slope (%) Impervious Roughness (--) Pervious Roughness (--) Imperv. Storage (in)) Perv. Storage (in) Zero Storage (%) Max. Infiltration Rate (in/hr) Min. Infiltration Rate (in/hr) Decay Constant (1/hr) Drying Time (days) Villa_Duch DC_4 205.27 7.5 4229 7.43 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Warson_T DC_7 309.21 7.7 5190 5.83 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Warson_W DC_13 1111.6 12.1 5904.6 6.83 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Waverton DC_9 391.33 6.7 5839 5.65 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Westwood DC_2 887.76 12.8 8794.5 5.86 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Winding_R DC_8 191.92 7.2 4089 5.8 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Windrush_Cr DC_3 583.13 10.3 4276.5 6.7 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 1-0 LRDP_20 977.03 11.6 9226 6.37 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 2-0 McC_5 89.74 10.4 2796 8.23 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 3-0 McC_4 615.31 11.1 7321.5 7.11 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 5-0 McC_2 505.33 11.9 6635 4.97 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 6-0 McC_2 211.91 10.3 4296.5 4.81 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 7-0 McC_3 844.31 13.9 8576.5 5.78 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 8-0 McC_4 545.03 15.2 6891 6.2 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 9-0 LRDP_16 313.44 13.6 5225.5 7.34 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Pointview LRDP_18 82.3 11.3 2677.5 7.05 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Commun GC_5 811.08 12.1 8406 7.27 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Cor_Jesu GC_6 828.48 9.4 8495.5 6.77 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Forder GC_12 838.27 10.9 8545.5 6.11 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Forever GC_3 1944.94 12.9 13017 5.55 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Green_P GC_10 549.62 11.3 6919.5 7.31 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Hancock_Pl GC_14 536.58 11.1 6837 5.6 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Lindbergh_HS GC_7 1626.51 11.4 11904 6.81 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Margaret_B GC_11 1037.55 11.9 9507.5 6.38 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Mesnier GC_13 1468.27 13.7 11310 5.68 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Precious GC_9 979.88 13.6 9239.5 6.84 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Saint_Simon GC_8 1312.08 11 10691.5 7.46 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Saint_Timothy GC_14 362.61 13.3 5620.5 4.26 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Truman_Elem GC_4 2224.8 11.3 13922 7.83 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315 Ursuline GC_2 1603.97 11.5 11821 4.85 0.017 0.25 0.1 0.25 5 0.5 0.04 3.6 0.02315     F‐3 Lower River des Peres SWMM5 Model: Conduit Data  Conduit Name Inlet Node Outlet Node Length (feet) Roughness (--) Inlet Offset (feet) Outlet Offset (feet) Initial Flow (cfs) Maximum Flow (cfs) Shape Maximum Depth (feet) Bottom Width (feet) Left Slope (h:v) Right Slope (h:v) Barrels (--) DCa_1-2 DC_1 DC_2 7073.8 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_2-3 DC_2 DC_3 3061.4 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_3-4 DC_3 DC_4 2831.9 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_4-5 DC_4 DC_5 1742.5 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_5-6 DC_5 DC_6 2022.0 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_6-7 DC_6 DC_7 2371.8 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_7-8 DC_7 DC_8 1496.8 0.025 0 0 0 0 Trapezoidal 10 20 1 1 1 DCa_8-9 DC_8 DC_9 930.7 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_9-10 DC_9 DC_10 2442.5 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_10-11 DC_10 DC_11 2839.6 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_11-12 DC_11 DC_12 1488.0 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_12-13 DC_12 DC_13 1340.4 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_13-14 DC_13 DC_14 2619.1 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_14-15 DC_14 DC_15 1965.2 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_15-16 DC_15 DC_16 1317.5 0.025 0 0 0 0 Trapezoidal 12 20 1 1 1 DCa_16-17 DC_16 DC_17 981.3 0.025 0 0 0 0 Trapezoidal 12 20 1 1 1 DCa_17-18 DC_17 DC_18 2147.3 0.025 0 0 0 0 Trapezoidal 12 20 1 1 1 DCa_18-19 DC_18 DC_19 1306.7 0.025 0 0 0 0 Trapezoidal 12 20 1 1 1 DCa_19-20 DC_19 DC_20 1732.9 0.025 0 0 0 0 Trapezoidal 12 20 1 1 1 DCa_20-21 DC_20 DC_21 2558.0 0.025 0 0 0 0 Trapezoidal 12 25 1 1 1 DCa_21-22 DC_21 DC_22 1642.3 0.025 0 0 0 0 Trapezoidal 15 30 1 1 1 DCa_22-23 DC_22 DC_23 1846.7 0.025 0 0 0 0 Trapezoidal 15 30 1 1 1 DCb_24-20 DCa_24 DC_20 4863.8 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 McCa_1-2 McC_1 McC_2 5380.6 0.03 0 0 0 0 Trapezoidal 8 12 1 1 1 McCa_2-3 McC_2 McC_3 2836.3 0.03 0 0 0 0 Trapezoidal 8 12 1 1 1 McCa_3-4 McC_3 McC_4 3094.0 0.03 0 0 0 0 Trapezoidal 8 12 1 1 1 McCa_4-5 McC_4 McC_5 2341.8 0.03 0 0 0 0 Trapezoidal 8 12 1 1 1 GCa_1-2 GC_1 GC_2 8273.9 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_2-3 GC_2 GC_3 4641.2 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_3-4 GC_3 GC_4 2000.8 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_4-5 GC_4 GC_5 4978.8 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_5-6 GC_5 GC_6 2002.6 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_6-7 GC_6 GC_7 4779.7 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_7-8 GC_7 GC_8 3878.3 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_8-9 GC_8 GC_9 3763.7 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_9-10 GC_9 GC_10 2898.8 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_10-11 GC_10 GC_11 3438.2 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_11-12 GC_11 GC_12 3775.4 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1  F‐4 Conduit Name Inlet Node Outlet Node Length (feet) Roughness (--) Inlet Offset (feet) Outlet Offset (feet) Initial Flow (cfs) Maximum Flow (cfs) Shape Maximum Depth (feet) Bottom Width (feet) Left Slope (h:v) Right Slope (h:v) Barrels (--) GCa_12-13 GC_12 GC_13 2109.2 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_13-14 GC_13 GC_14 4502.7 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 GCa_14-15 GC_14 GC_15 3475.8 0.03 0 0 0 0 Trapezoidal 8 15 1 1 1 DC-LRDP DC_23 DeerCreekStorage 963.0 0.03 0 10.39 0 0 Trapezoidal 15 25 1 1 1 McC-LRDP McC_5 LRDP_18 1258.5 0.03 0 10.85 0 0 Trapezoidal 8 12 1 1 1 GC-LRDP GC_15 GravoisStorage 279.8 0.03 0 4 0 0 Trapezoidal 8 15 1 1 1     F‐5  Lower River des Peres SWMM5 Model: Node Data   Name Invert (feet) Maximum Depth (feet) Initial Depth (feet) Surcharge Depth (feet) Ponded Area (ft2) DC_1 629 10 0.2 0 0 DC_2 548 10 0.2 0 0 DC_3 526 10 0.2 0 0 DC_4 518 10 0.2 0 0 DC_5 510 10 0.2 0 0 DC_6 499 10 0.2 0 0 DC_7 489.5 10 0.2 0 3000 DC_8 483.5 10 0.2 0 0 DC_9 479.8 10 0.2 0 0 DC_10 470 10 0.2 0 3000 DC_11 463.2 10 0.2 0 3000 DC_12 459 10 0.2 0 4000 DC_13 455 10 0.2 0 4000 DC_14 446 10 0.2 0 4000 DC_15 442.1 10 0.2 0 4000 DC_16 439.5 10 0.2 0 6000 DC_17 437.5 10 0.2 0 8000 DC_18 433.2 10 0.2 0 8000 DC_19 428 10 0.2 0 0 DC_20 426 10 0.2 0 0 DC_21 423 10 0.2 0 0 DC_22 421.5 10 0.2 0 0 DC_23 418 10 0.2 0 0 DCa_24 455 10 0.2 0 0 McC_1 568 10 0.2 0 0 McC_2 484 10 0.2 0 0 McC_3 445 10 0.2 0 0 McC_4 418 10 0.2 0 0 McC_5 414 10 0.2 0 0 GC_1 630 10 0.2 0 0 GC_2 558 10 0.2 0 0 GC_3 518 10 0.2 0 0 GC_4 509 10 0.2 0 0 GC_5 489 10 0.2 0 0 GC_6 478 10 0.2 0 0 GC_7 467 10 0.2 0 0 GC_8 452 10 0.2 0 0 GC_9 449 10 0.2 0 0 GC_10 438 10 0.2 0 0 GC_11 429 10 0.2 0 0 GC_12 419 10 0.2 0 0 GC_13 417 10 0.2 0 0 GC_14 405 10 0.2 0 0 GC_15 396 10 0.2 0 0      F‐6 Maline Creek SWMM5 Model: Subcatchment Data  Subcatchment Name Outlet Node Area (acres) Impervious Fraction (%) Runoff Width (feet) Slope (%) Impervious Roughness (--) Pervious Roughness (--) Imperv. Storage (in)) Perv. Storage (in) Zero Storage (%) Max. Infiltration Rate (in/hr) Min. Infiltration Rate (in/hr) Decay Constant (1/hr) Drying Time (days) Bellefontaine MC_12 1457.8 22.3 1992.2 6.034 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Bissell_Hills MC_13 677.4 21.4 1358.02 6.6977 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Black_Jack MC_18 634.3 23.6 3942.33 6.536 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Black_Jack1 MC_16 812.6 25.6 4462.14 9.9822 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Carson_Vila MC_1 160.3 34.8 660.62 7.0574 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Community_Co MC_21 1157.5 31.2 5325.57 9.7498 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Home_Depot MC_14 16.3 76.7 210.66 2.7659 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Dellwood MC_19 451.8 28.9 2218.13 6.2891 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Edgewood MC_2 1956.6 30 2308 7.3745 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Forestwood MC_5 521.6 29.3 3574.98 7.9331 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Hanley MC_4 1531.5 25.2 2041.94 9.2531 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Hathaway MC_20 936.1 29.5 1596.41 5.5871 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Jeske MC_5 443.4 35.9 3296.12 5.9622 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Lang_Royce MC_7 1618.1 29.5 6296.63 6.0292 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Maline_Relief MC_14 272.9 23.4 861.96 5.3858 0.025 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 New_Halls_Ferry MC_9 931.9 32.8 1592.83 7.9795 0.017 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Riverview MC_14 965.5 39.2 1621.29 5.0678 0.017 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Solway MC_6 618.5 29.3 1297.64 9.4975 0.017 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 Thurston MC_3 1234.8 20.8 1833.51 6.5343 0.017 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315 West_Branch MC_17 1242 31.4 5516.53 9.0896 0.017 0.25 0.1 0.25 25 0.5 0.04 3.6 0.02315     F‐7 Maline Creek SWMM5 Model: Conduit Data  Conduit Name Inlet Node Outlet Node Length (feet) Roughness (--) Inlet Offset (feet) Outlet Offset (feet) Initial Flow (cfs) Maximum Flow (cfs) Shape Maximum Depth (feet) Bottom Width (feet) Left Slope (h:v) Right Slope (h:v) Barrels (--) MCa_1-2 MC_1 MC_2 9402.0 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_2-3 MC_2 MC_3 2537.9 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_3-4 MC_3 MC_4 4065.8 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_4-5 MC_4 MC_5 2490.2 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_5-6 MC_5 MC_6 2799.1 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_6-7 MC_6 MC_7 1238.0 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_7-8 MC_7 MC_8 1354.7 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_8-9 MC_8 MC_9 4523.5 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCa_9-10 MC_9 MC_10 5067.3 0.025 0 0 0 0 Trapezoidal 10 30 1 1 1 MCa_10-11 MC_10 MalineUpstream 2000.0 0.025 0 15 0 0 Trapezoidal 10 30 1 1 1 MCb_16-17 MC_16 MC_17 3120.0 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCb_17-18 MC_17 MC_18 2356.9 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCb_18-19 MC_18 MC_19 2527.7 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCb_19-20 MC_19 MC_20 4029.8 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCb_20-10 MC_20 MC_10 944.0 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1 MCc_21-19 MC_21 MC_19 4827.2 0.025 0 0 0 0 Trapezoidal 8 15 1 1 1     F‐8  Maline Creek SWMM5 Model: Node Data   Name Invert (feet) Maximum Depth (feet) Initial Depth (feet) Surcharge Depth (feet) Ponded Area (ft2) MC_1 589 10 0.2 0 0 MC_2 493 10 0.2 0 0 MC_3 489 10 0.2 0 0 MC_4 476 10 0.2 0 0 MC_5 468 10 0.2 0 0 MC_6 461.8 10 0.2 0 0 MC_7 459 10 0.2 0 0 MC_8 458 10 0.2 0 0 MC_9 449 10 0.2 0 0 MC_10 427 12 0.2 0 0 MC_16 472.4 10 0.2 0 0 MC_17 459.3 10 0.2 0 0 MC_18 449.5 10 0.2 0 0 MC_19 439.6 10 0.2 0 0 MC_20 429 10 0.2 0 0 MC_21 472.4 10 0.2 0 0        F‐9 Upper River des Peres SWMM5 Model: Subcatchment Data  Subcatchment Name Outlet Node Area (acres) Impervious Fraction (%) Runoff Width (feet) Slope (%) Impervious Roughness (--) Pervious Roughness (--) Imperv. Storage (in)) Perv. Storage (in) Zero Storage (%) Max. Infiltration Rate (in/hr) Min. Infiltration Rate (in/hr) Decay Constant (1/hr) Drying Time (days) HanleyHills HanleyHillsStorage 1488.01 28 930 5.8 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Mendell MendellStorage 893.09 20.6 2232 1.8 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Westgate WestgateStorage 95.51 21.8 239 7.8 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Midland MidlandStorage 473.16 17.1 1183 1.3 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Vernon VernonStorage 86.1 17.6 215 1.3 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Balson 17K3-071C 510.15 13.4 1276 0.5 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 Shaftsbury ShaftsburyStorage 116.6 21.04 292 1.5 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 SouthOverland 1005 1334 7.2 6670 0.6 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 WarsonPark 1001 1410.81 9 7054 0.4 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 SouthPrice 1030 1067.33 7.2 5336 1.4 0.014 0.2 0.1 0.25 5 2 0.07 2.6 2 HemanPark HemanParkStorage 396.85 10.2 992 1.1 0.014 0.2 0.1 0.25 5 0.5 0.07 2.6 2 NOTE: Conduit and node data are not included for this model because no open channels were modeled; instead, outflow from each subcatchment was routed directly to the FEQ model This page is blank to facilitate double-sided printing. Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX G Description of Photosynthesis & Respiration Algorithm This page is blank to facilitate double-sided printing. G-1 An alternate method of computing the diurnal variation in dissolved oxygen that results from water column photosynthesis and respiration was added to the WASP code. This Appendix describes the equations and parameters that are used. Proposed Method of Estimating P-R Chapra (1997) reports a method that is based on available light and biomass. It assumes that nutrients are not a limiting factor, which is expected to be a reasonable assumption for all of the St. Louis-area receiving waters. The method requires the estimation of several parameters related to photosynthesis and respiration that are commonly available in the literature, or through site- specific measurements; these parameters are summarized in Table G-1. Table G-1. Parameters required in order to estimate P-R from algal biomass measurements. Parameter Symbol Units Data Source for Parameter Biomass a mg-Chla/m3 Site specific data preferred Available Light Ia langleys/hr Routinely available at meteorological stations O2 generated/ mg-Chla roa g O/mg-Chla Available from literature Maximum Algal growth rate for optimal conditions Gmax hr-1 Available from literature Water temperature T °C Input to existing model Optimal light intensity Is ly/hr Available from literature Light extinction coefficient ke m-1 Can be related to Secchi-disk depth, and other measurable parameters, or estimated. Respiration rate kra hr-1 Available from literature Depth H m Currently simulated by model Photoperiod (fraction of hour subject to light) f unitless Set to 1 for hours with light, and 0 for hours without light The equations for photosynthesis and respiration provided by Chapra (1997) are below. Chapra presents these as suitable for daily P-R. These same equations will be used to develop hourly P-R by using hourly time series of available light and an hourly rates. Photosynthesis (g O/m3-hr) is represented as: aGrPT oa φ)20( max 066.1 −= (G-1) G-2 The parameter φ in equation G-1 represents the attenuation of growth due to light, which is represented as: )(718.2 01ααφ−−−=eeHk f e (G-2) where Hk s a eeI I −=1α (G-3) and s a I I=0α (G-4) The value of φ ranges between 0 and 1, which reflects the effect of light on plant growth. A value of 1 represents the oxygen production at optimal light levels. The other terms in equations G-1 through G-4 are defined in Table G-1. Respiration (g O/m3-hr) is represented as: R=roakra1.08T-20a (G-5) This method is recommended for adaptation to WASP because it is simple and predictive, relying on parameters that are either currently simulated (H, T), readily available in the literature (roa, Gmax, Is, ke, kra), or easily obtained from other sources (Ia). Ideally biomass would be measured (as chlorophyll a, for example); however, with continuous DO data available the biomass parameter would serve as a calibration parameter. The method is also useful because predicted P-R will be at a sufficiently fine time-step to simulate diurnal DO fluctuations. References Chapra, S.C, 1997. Surface Water-Quality Modeling. McGraw Hill, 1997 Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX H Technologies Matrix This page is blank to facilitate double-sided printing. APPENDIX H Technologies Matrix H-1 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS COLLECTION SYSTEM CONTROLS Infiltration/Inflow Reduction yes no no no no no Labor intensive; reducing infiltration may have minimal impact on CSO volume due to its small magnitude compared to inflow CSO Diversion Structure Improvement Program yes yes yes yes yes yes Relatively easy to implement Sewer System Cleaning/ Flushing yes yes yes yes yes yes Maximizes existing collection system; reduces first flush effect; labor intensive Sewer/CSO Diversion Structure Maintenance no no no no no no Inspection; removal of debris; increases flow to plant Outfall Maintenance Program no no no no no no Reduces stream intrusion into sewer collection system House Lateral Repairs yes no no no no no House laterals typically account for 1/2 the sewer system length and significant sources of I/I; repairs by homeowners Engineering/Structural Real Time Control yes yes yes yes yes yes Highly automated system; mechanical controls require O&M, increases potential for backups; can hold overflows in more sensitive areas Sewer Separation yes no no no small no Part of most CSO LTCPs; required to correct basement backup problems; expensive; disruptive to neighborhoods; effectiveness of separation has been reassessed in recent years - increased loads of stormwater runoff pollutants (sediments, bacteria, oil, metals); bacteria is of a lower concentration Industrial Source Separation yes no no no small no Disruptive, costly, some cost borne by industry Outfall Consolidation/ Relocation no no no no no no Directs flow away from specific area; low operational cost; reduces permitting & monitoring; can be used in conjunction w/storage and treatment technologies APPENDIX H Technologies Matrix H-2 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS STORAGE TECHNOLOGIES Storage Before Sewer Industrial Discharge Detention yes yes yes no small yes Toxics Reduction Industry to hold stormwater or combined sewage until after the storm Wet Storage Ponds yes yes yes no small yes Siting, land requirements make location selection difficult; low cost solution; stormwater is discharged to the river or combined sewer, bacteria is at a lower concentration Dry Storage Ponds yes yes yes no small yes Siting, land requirements make location selection difficult; low cost solution; stormwater is discharged to the river, bacteria is at a lower concentration Storage in Sewer System In-line Storage – Interceptor yes yes yes no no yes Increases O&M costs; increases potential for basement flooding; maximizes use of existing facilities; interceptors have very little wet weather storage capacity In-line Storage – Trunk Sewer yes yes yes yes yes yes Increases O&M costs; increases potential for basement flooding; maximizes use of existing facilities Off-line Storage Tunnels in Rock and Soil yes yes yes yes yes yes Eliminates land restrictions and costs associated with storage basins; can provide large storage volumes with relatively minimal disturbance to ground surface - beneficial in congested urban areas; takes advantage of uneven distribution of rainfall; use as conveyance; higher cost than open storage APPENDIX H Technologies Matrix H-3 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Off-line Covered Storage / Sedimentation Tanks yes yes yes yes yes yes Includes variation of retention, detention and flow-through systems; requires large area for location of underground basin; increases O&M costs; potentially high neighborhood disturbance; cost increases with depth; ex. several Michigan CSO Projects Off-line Open Storage / Sedimentation Tanks yes yes yes yes yes yes Includes variation of retention, detention and flow-through systems; requires area for location of above-ground basin; increases O&M costs; odor issues a consideration; ex. Louisville, KY TREATMENT TECHNOLOGIES At CSO Facility Storage Tank – Sedimentation yes yes yes no no yes Includes variation of retention, detention and flow-through systems; requires large area for location of underground basin; increases O&M costs; potentially high neighborhood disturbance; cost increases with depth; ex. several Michigan CSO Projects Clarification - Solids Contact no yes yes no no yes Peak loading = 1 gpm/ft2; ex. storage/chlorine contact tanks; solids and disinfection are concerns; larger footprint than vortex separation or ballasted flocculation, but easier to operate High Rate Clarification no yes yes no no yes Peak loading = 40 gpm/ft2; piloted in Indianapolis; ex. Actiflo, Densadeg, Microsep; high O&M costs; limited ammonia removal; smaller footprint Vortex Separation no no yes no no yes Peak loading = 10 gpm/ft2; solids reduction varies widely; increased O&M costs; ex. Columbus, GA Compressed Media Filtration no yes yes no no yes Peak loading = 20 gpm/ft2; 70% particle removal; limited ammonia removal; backwashing is required APPENDIX H Technologies Matrix H-4 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Biological Treatment no yes yes yes no no Higher level of treatment Chemical Disinfection and Dechlorination no no no no yes no Effective against bacteria; easily available; widely used; inexpensive; effective when solids are present; requires operator attention; long detention time and dechlorination required, creating added expense; health concerns; produces chlorinated byproducts UV Disinfection no no no no yes no Good results in Columbus, GA. Being piloted in Richmond, VA; few safety risks; less effective when suspended solids above 30 mg/l are present Mechanical Screens no no no no no yes Mechanical device requires additional O&M; weir-mounted is less expensive Over/under Baffles no no no no no yes Might have to completely rebuild CSO diversion structure Netting Systems no no no no no yes Labor intensive At Existing Treatment Facility Maximize Flow to WWTP Plant yes yes yes yes yes yes NPDES Permit requirement Screening no no no no no yes Costly for little benefit. Requires added WWTP treatment capacity – at least clarification and disinfection. Conventional Clarification no yes yes no no yes Peak loading = 1 gpm/ft2; ex. Storage/chlorine contact tanks; solids and disinfection a concern; larger footprint than vortex separation or ballasted flocculation, but easier to operate High Rate Clarification no yes yes no no yes Peak loading = 40 gpm/ft2; piloted in Indianapolis; ex. Actiflo, Densadeg, Microsep; high O&M costs; limited ammonia removal; smaller footprint APPENDIX H Technologies Matrix H-5 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Vortex Separation no no yes no no yes Peak loading = 10 gpm/ft2; solids reduction varies widely; increased O&M costs; ex. Columbus, GA Compressed Media Filtration no yes yes no no yes Peak loading = 20 gpm/ft2; 70% particle removal; limited ammonia removal; backwashing is required Deepbed Filtration no yes yes no no yes Efficient at removing BOD, ammonia, and solids Biological Treatment no yes yes yes no no Higher level of treatment Chemical Disinfection (and Dechlorination no no no no yes no Effective against bacteria; easily available; widely used; inexpensive; effective when solids are present; requires operator attention; long detention time and dechlorination required, creating added expense; health concerns; produces chlorinated byproducts UV Disinfection no no no no yes no Good results in Columbus, GA. Being piloted in Richmond, VA; few safety risks; less effective when suspended solids above 30 mg/l are present Equalization Open Storage yes yes yes yes yes yes Odors must be monitored; requires a lot of space Equalization Closed Storage yes yes yes yes yes yes Requires a lot of space SOURCE CONTROL TECHNOLOGIES Stormwater Management Wet Storage Ponds yes yes yes no no yes Siting, land requirements make location selection difficult; low cost solution; if stormwater is discharged to the river, bacteria is at a lower concentration APPENDIX H Technologies Matrix H-6 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Dry Storage Ponds yes yes yes no no yes Siting, land requirements make location selection difficult; low cost solution; if stormwater is discharged to the river, bacteria is at a lower concentration Wetlands Treatment yes yes yes yes yes yes Siting, land requirements make location selection difficult; low cost solution; expensive if influent pumping is required Sump Pump Disconnect Program yes no no no no no Sump pumps are connected to combined sewers in some old neighborhoods; cost to homeowner; interaction with homeowners required Catch Basin Cleaning no yes yes no no yes Labor intensive; specialized equipment required Illicit Connection Control no yes yes no no yes MSD Ordinance in place. Roof Leader Disconnect Program yes no no no no no Rain leaders are connected to combined sewers in some old neighborhoods; cost to homeowner; interaction with homeowners required Leaching Catch Basins (Dry Wells) yes yes yes yes yes yes Limited by potential for contaminating ground water; required for parking lots of new developments Swales & Filter Strips yes yes yes yes yes yes Limited by potential for contaminating ground water; good BMP; low operational cost Porous Pavement yes yes no yes yes no Not durable; clogs in winter; oil and grease will clog; high maintenance and related costs Parking Lot Storage yes yes yes no no yes Limited by potential for lot and yard flooding; freezing potential; low operational cost; ex. Skokie and Wilmette, IL Street Storage (Catch Basin Inlet Control) yes yes yes no no yes Limited by potential for pedestrians getting their feet wet; freezing potential; low operational cost; ex. Evanston, IL Green Solutions – General yes yes yes yes yes yes Siting, land requirements make location selection difficult; low cost solution; improves aesthetics APPENDIX H Technologies Matrix H-7 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Solid Waste Collection/Disposal Illegal Dumping Control no no yes no no yes Municipal Governments ordinances in place. Solid Waste Program no no no no no yes Ongoing Municipal Governments’ commitment Hazardous Waste Collection no no no no no no Toxics Removal Disposal through existing County recycling center. Public Education Water Conservation yes no no no no no Coordination with Water Utility required Catch Basin Stenciling no no no no no yes Toxics Reduction Ongoing MSD commitment Community Cleanup Program no no no no no yes Inexpensive; sense of community spirit; educational BMP; aesthetic enhancement Public Education Programs -- -- -- -- -- -- -- Ongoing MSD/Municipal Governments’/local organizations’ commitments Recycling Programs no no no no no yes Toxics Reduction Ongoing Municipal Governments’ commitment Warning Signage no no no no no no Ongoing MSD commitment Construction Related Onsite Erosion Control/ New Construction no no yes no no no Contractor/owner pays for erosion control; reduces clogging of catch basin; reduces sediment and silt loads to stream; enforcement Soil Stabilization Measures no no yes no no no Construction associated; ongoing; in Building Code; reduces silt loads to stream; enforcement Stabilized Construction Entrance no no yes no no no Ongoing; in Building Code and related projects’ specifications APPENDIX H Technologies Matrix H-8 ENVIRONMENTAL IMPACTS AND IMPROVEMENTS TECHNOLOGIES CSO Volume Reduction Light Solids Reduction Heavy Solids Reduction Soluble Organics Reduction Bacteria Reduction Floatables Reduction Other IMPLEMENTATION AND OPERATION FACTORS Good Housekeeping Industrial Spill Control no no no no no no Toxics Reduction On-going MSD Industrial Pretreatment Program regulated by EPA Street Sweeping Programs no no yes no no yes Does not address flow or bacteria Litter Ordinance Enforcement no no no no no yes Aesthetic enhancement; labor intensive Miscellaneous Industrial Pretreatment Program no no no no no no Toxics Reduction Ongoing MSD Industrial Pretreatment Program Streambank Stabilization/Restoration no no yes no no no On-going MSD program; aesthetic enhancement; streambank restoration; Septic Tank Improvements no no no no yes no Important for bacteria reduction in localized areas and streams during dry weather periods Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX I Level 3 Alternatives Analysis Cost Summaries This page is blank to facilitate double-sided printing. Appendix IReceiving Stream Segment: Maline CreekAlternative: Alternative 1 - Local Storage for Outfalls 051and 05218161412108643210Capital Costs ($million)Conveyance (1)4.7 4.7 4.7 4.7 4.7 4.7 4.7 6.8 6.8 6.8 6.8 6.8Local Storage Tank(s) 6.6 8.5 10.5 12.3 15.9 23.5 25.4 35.7 48.9 73 94.1 141.9Storage Tank Pump Station(s) (2)0.8 0.9 1.1 1.2 1.5 2.2 2.4 3.7 4.9 7.5 9.4 14.9Construction Subtotal 12.1 14.0 16.3 18.1 22.1 30.4 32.5 46.2 60.6 87.3 110.3 163.6Contingency (25%) 3.0 3.5 4.1 4.5 5.5 7.6 8.1 11.6 15.2 21.8 27.6 40.9Construction Total 15.1 17.5 20.4 22.6 27.6 38.0 40.6 57.8 75.8 109.1 137.9 204.5Engineering, Legal, Admin. (20%) 3.0 3.5 4.1 4.5 5.5 7.6 8.1 11.6 15.2 21.8 27.6 40.9Total Capital Cost 18.1 21.0 24.4 27.2 33.2 45.6 48.8 69.3 90.9 131.0 165.5 245.4O & M Costs ($million/yr)Operations (Labor) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.7 0.9 0.9 0.9 0.9Maintenance 0.2 0.3 0.4 0.4 0.5 0.8 0.8 1.2 1.6 2.4 3.1 4.7Pump Station Power0.0003 0.0004 0.0004 0.0005 0.0006 0.0008 0.0008 0.0010 0.0011 0.0014 0.0014 0.0015Total Annual O & M 0.6 0.6 0.7 0.8 0.9 1.2 1.2 1.9 2.5 3.3 4.0 5.6Present Worth Cost ($million)Total Capital Cost 18.1 21.0 24.4 27.2 33.2 45.6 48.8 69.3 90.9 131.0 165.5 245.4Total O & M Cost 6.3 6.9 7.6 8.2 9.4 12.0 12.7 20.3 26.8 35.3 42.6 59.5Total Present Worth 24 28 32 35 43 58 61 90 118 166 208 305(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 42-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-1 Appendix IReceiving Stream Segment: Maline CreekAlternative: Alternative 2 - Local Treatment for Outfall 051, and Local Storage for Outfall 05218161412108643210Capital Costs ($million)Conveyance (1)4.7 4.7 4.7 4.7 4.7 4.7 4.7 6.8 6.8 6.8 6.8 6.8Local Treatment Unit 3.1 3.2 4.0 5.3 6.5 7.5 8.7 10.6 11 12.7 14.5 18.2Disinfection Facilities 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3Local Storage Tank(s)-------1.34.54.925.2 39.3Storage Tank Pump Station(s) (2)-------0.40.60.62.43.8Construction Subtotal 8.1 8.1 8.9 10.3 11.5 12.5 13.7 19.4 23.2 25.3 49.2 68.4Contingency (25%) 2.0 2.0 2.2 2.6 2.9 3.1 3.4 4.9 5.8 6.3 12.3 17.1Construction Total 10.1 10.2 11.1 12.9 14.4 15.6 17.1 24.3 29.0 31.6 61.5 85.5Engineering, Legal, Admin. (20%) 2.0 2.0 2.2 2.6 2.9 3.1 3.4 4.9 5.8 6.3 12.3 17.1Total Capital Cost 12.1 12.2 13.4 15.5 17.3 18.8 20.6 29.1 34.8 38.0 73.8 102.6O & M Costs ($million/yr)Operations (Labor) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.5 0.5Maintenance 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.4 0.5 0.5 1.3 1.8Chemicals 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01Pump Station Power (3)0.0000 0.0000 0.0000 0.0005 0.0006 0.0008 0.0008 0.0010 0.0011 0.0014 0.0014 0.0015Total Annual O & M 0.5 0.5 0.5 0.6 0.6 0.6 0.7 0.9 1.0 1.0 1.8 2.3Present Worth Cost ($million)Total Capital Cost 12.1 12.2 13.4 15.5 17.3 18.8 20.6 29.1 34.8 38.0 73.8 102.6Total O & M Cost 5.0 5.0 5.3 5.7 6.1 6.4 6.8 9.9 11.1 11.8 19.4 25.5Total Present Worth 17 17 19 21 23 25 27 39 46 50 93 128(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 42-hour pump out time(3) Power for treatment unit was not estimated and is assumed to be negligibly small as compared to the annual operations and maintenance costs.ENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-2 Appendix IReceiving Stream Segment: Gingras CreekAlternative: Alternative 1 - Outfall RelocationLevel of Control (Overflows per Year)0 (Outfall Relocation)Capital Costs ($million)Conveyance (1)2.7Storm Sewer Separation 1.1Construction Subtotal 3.8Contingency (25%) 1.0Construction Total 4.8Engineering, Legal, Admin. (20%) 1.0Total Capital Cost 5.7O & M Costs ($million/yr)Operations (Labor) 0.0Maintenance 0.01Total Annual O & M 0.01Present Worth Cost ($million)Total Capital Cost 5.7Total O & M Cost 0.1Total Present Worth 5.8(1) Extend the existing 66-inch outfall to the Baden Sewer SystemENR CCI = 8100I-3 Appendix IReceiving Stream Segment: Gingras CreekAlternative: Alternative 2 - Local Storage12108643210Capital Costs ($million)Conveyance (1)1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0Storm Sewer Separation1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1Local Storage Tank(s)0.2 0.7 1.0 1.1 2.1 4.7 5.1 8.6 10.9Storage Tank Pump Station(s) (2)0.4 0.4 0.4 0.4 0.5 0.6 0.6 0.9 1.1Construction Subtotal2.7 3.2 3.5 3.6 4.7 7.4 7.8 11.6 14.1Contingency (25%)0.7 0.8 0.9 0.9 1.2 1.9 2.0 2.9 3.5Construction Total3.4 4.0 4.4 4.5 5.9 9.3 9.8 14.5 17.6Engineering, Legal, Admin. (20%)0.7 0.8 0.9 0.9 1.2 1.9 2.0 2.9 3.5Total Capital Cost4.1 4.8 5.3 5.4 7.1 11.1 11.7 17.4 21.2O & M Costs ($million/yr)Operations (Labor) 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18Maintenance 0.02 0.03 0.04 0.05 0.08 0.16 0.17 0.29 0.36Pump Station Power0.000002 0.000006 0.000009 0.000010 0.000017 0.000032 0.000034 0.000045 0.000049Total Annual O & M 0.2 0.2 0.2 0.2 0.3 0.3 0.4 0.5 0.5Present Worth Cost ($million)Total Capital Cost 4.1 4.8 5.3 5.4 7.1 11.1 11.7 17.4 21.2Total O & M Cost 2.2 2.3 2.4 2.5 2.8 3.6 3.8 5.0 5.8Total Present Worth 6.3 7.1 7.7 7.9 9.9 14.7 15.5 22.4 27.0(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-4 Appendix IReceiving Stream Segment: Gingras CreekAlternative: Alternative 3 - Local Treatment12108643210Capital Costs ($million)Conveyance (1)1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0Storm Sewer Separation1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1Local Treatment Unit0.3 0.6 0.8 1.0 1.8 2.3 2.3 2.6 3.0Disinfection Facilities0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3Construction Subtotal2.7 3.0 3.2 3.4 4.2 4.7 4.7 5.0 5.4Contingency (25%)0.7 0.8 0.8 0.9 1.1 1.2 1.2 1.3 1.4Construction Total3.4 3.8 4.0 4.3 5.3 5.9 5.9 6.3 6.8Engineering, Legal, Admin. (20%)0.7 0.8 0.8 0.9 1.1 1.2 1.2 1.3 1.4Total Capital Cost4.1 4.5 4.8 5.1 6.3 7.1 7.1 7.5 8.1O & M Costs ($million/yr)Operations (Labor) 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18Maintenance 0.02 0.03 0.03 0.04 0.06 0.08 0.08 0.09 0.10Chemicals 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002Power (2)0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Total Annual O & M 0.20 0.21 0.21 0.22 0.24 0.26 0.26 0.27 0.28Present Worth Cost ($million)Total Capital Cost 4.1 4.5 4.8 5.1 6.3 7.1 7.1 7.5 8.1Total O & M Cost 2.2 2.2 2.3 2.4 2.6 2.8 2.8 2.9 3.0Total Present Worth 6.3 6.7 7.1 7.5 8.9 9.9 9.9 10.4 11.1Level of Control (Overflows per Year)I-5 Appendix IReceiving Stream Segment: Mississippi RiverAlternative: Tunnel Storage for Bissell Point Outfalls and Storage Tanks for Lemay Outfalls18161412108643210Capital Costs ($million)Conveyance (1)309 309 309 309 309 309 309 309 309 309 309 309Tunnel(s)285 295 305 317 353 422 453 758 1266 1359 1876 2361Tunnel Pump Station(s) (2)29 29 29 31 32 32 32 32 32 32 32 32Local Storage Tank(s)11 19 23 25 30 33 39 47 55 77 84 116Storage Tank Pump Station(s) (3)2344445568811Construction Subtotal636 655 670 686 728 800 838 1151 1668 1785 2309 2829Contingency (25%)159 164 168 172 182 200 210 288 417 446 577 707Construction Total795 819 838 858 910 1000 1048 1439 2085 2231 2886 3536Engineering, Legal, Admin. (20%)159 164 168 172 182 200 210 288 417 446 577 707Total Capital Cost954 983 1005 1029 1092 1200 1257 1727 2502 2678 3464 4244O & M Costs ($million/yr)Operations (Labor) 2.0 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5Maintenance 5.6 5.8 5.9 6.1 6.5 7.2 7.6 10.7 15.9 17.0 22.2 27.4Pump Stations Power 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.03 0.04 0.04 0.04 0.05Total Annual O & M 7.6 9.3 9.4 9.6 10.0 10.7 11.1 14.2 19.4 20.5 25.7 31.0Present Worth Cost ($million)Total Capital Cost 954 983 1005 1029 1092 1200 1257 1727 2502 2678 3464 4244Total O & M Cost 81 98 100 102 106 114 118 151 205 217 273 328Total Present Worth 1040 1090 1110 1140 1200 1320 1380 1880 2710 2900 3740 4580(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 126 mgd pump out limit(3) 18 hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-6 Appendix IReceiving Stream Segment: Upper River Des PeresAlternative: Tunnel Storage18161412108643210Capital Costs ($million)Conveyance (1)54 54 54 54 54 54 54 54 54 54 54 54Tunnel(s)39 39 42 44 45 50 54 58 73 84 115 132Tunnel Pump Station(s) (2)3.1 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.3 3.3 3.3Construction Subtotal96 96 99 101 102 107 111 115 130 141 172 189Contingency (25%)24 24 25 25 26 27 28 29 33 35 43 47Construction Total120 120 124 127 128 134 139 144 163 177 215 237Engineering, Legal, Admin. (20%)24 24 25 25 26 27 28 29 33 35 43 47Total Capital Cost144 144 149 152 153 161 167 173 195 212 258 284O & M Costs ($million/yr)Operations (Labor) 0.4 0.4 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5Maintenance 1.0 1.0 1.1 1.1 1.1 1.1 1.2 1.2 1.4 1.5 1.8 2.0Pump Stations Power 0.002 0.002 0.002 0.002 0.002 0.002 0.003 0.003 0.003 0.003 0.003 0.004Total Annual O & M 1.4 1.4 1.6 1.6 1.6 1.6 1.7 1.7 1.9 2.0 2.3 2.5Present Worth Cost ($million)Total Capital Cost 144 144 149 152 153 161 167 173 195 212 258 284Total O & M Cost 15 15 17 17 17 18 18 19 20 22 25 27Total Present Worth 160 160 170 170 180 180 190 200 220 240 290 320(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) Pump out limited to 10 mgdENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsI-7 Appendix IReceiving Stream Segment: River Des Peres TributariesAlternative: Alternative 1 - Conveyance Tunnel to One River Des Peres Outfall3210Capital Costs ($million)Conveyance (1)173 173 173 173Tunnel(s)60 81 87 162Tunnel Pump Station(s) (2)8 16.7 19.4 32.1Lemay Treatment Plant Upgrades8.4 15 16.8 25.2Construction Subtotal249 286 296 392Contingency (25%)62 71 74 98Construction Total312 357 370 490Engineering, Legal, Admin. (20%)62 71 74 98Total Capital Cost374 429 444 589O & M Costs ($million/yr)Operations (Labor) 0.7 0.7 0.7 0.7Maintenance 1.7 2.4 2.6 4.0Pump Stations Power 0.002 0.003 0.003 0.004Chemicals (Plant Upgrades) 0.030 0.035 0.036 0.038Total Annual O & M 2.4 3.1 3.3 4.7Present Worth Cost ($million)Total Capital Cost 374 429 444 589Total O & M Cost 26.5 33.7 35.8 50.5Total Present Worth 410 470 490 640(1) Conveyance is sized for conveying MSD design storm (20-year storm)(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-8 Appendix IReceiving Stream Segment: River Des Peres TributariesAlternative: Alternative 2 - Storage Tunnel with Consolidated Outfalls to the River Des Peres Tributaries18161412108643210Capital Costs ($million)Conveyance (1)65 65 65 65 65 65 65 65 65 65 65 65Tunnel(s)45 45 48 48 50 55 55 57 61 76 79 94Tunnel Pump Station(s) (2)2.3 2.4 3 3.1 4 5.4 5.9 6.1 8 13.5 14.9 21.5Lemay Treatment Plant Upgrades3.1 3.2 3.8 3.9 4.8 6.1 6.7 6.8 8.4 12.7 13.7 18.3Construction Subtotal115 116 120 120 124 132 133 135 142 167 173 199Contingency (25%)28.9 28.9 30.0 30.0 31.0 32.9 33.2 33.7 35.6 41.8 43.2 49.7Construction Total144 145 150 150 155 164 166 169 178 209 216 249Engineering, Legal, Admin. (20%)29 29 30 30 31 33 33 34 36 42 43 50Total Capital Cost173 173 180 180 186 197 199 202 214 251 259 298O & M Costs ($million/yr)Operations (Labor) 0.5 0.5 0.5 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7Maintenance 0.9 0.9 1.0 1.0 1.1 1.2 1.2 1.3 1.4 1.9 2.0 2.5Pump Stations Power 0.001 0.001 0.001 0.001 0.001 0.002 0.002 0.002 0.002 0.002 0.002 0.002Chemicals (Plant Upgrades) 0.020 0.020 0.020 0.020 0.020 0.030 0.030 0.030 0.030 0.040 0.040 0.040Total Annual O & M 1.4 1.4 1.5 1.7 1.8 1.9 1.9 2.0 2.1 2.6 2.7 3.2Present Worth Cost ($million)Total Capital Cost 173 173 180 180 186 197 199 202 214 251 259 298Total O & M Cost 15.9 16.0 16.7 18.7 19.5 20.9 21.3 21.6 23.2 27.9 29.0 34.2Total Present Worth 190 190 200 200 210 220 230 230 240 280 290 340(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-9 Appendix IReceiving Stream Segment: Lower and Middle River Des PeresAlternative: Alternative 1 - Storage Tunnel under Entire River Des Peres18161412108643210Capital Costs ($million)Conveyance (1)239 239 239 239 239 239 239 239 239 239 239 239Tunnel(s)299 310 310 332 357 383 412 443 443 854 885 1057Tunnel Pump Station(s) (2)27 28 30 38 46 55 64 72 74 114 119 143Dry Weather Conveyance Sewer33 33 33 33 33 33 33 33 33 33 33 33Lemay Treatment Plant Upgrades000000101820546085Construction Subtotal598 610 612 642 675 710 758 805 809 1294 1336 1557Contingency (25%)150 153 153 161 169 178 190 201 202 324 334 389Construction Total748 763 765 803 844 888 948 1006 1011 1618 1670 1946Engineering, Legal, Admin. (20%)150 153 153 161 169 178 190 201 202 324 334 389Total Capital Cost897 915 918 963 1013 1065 1137 1208 1214 1941 2004 2336O & M Costs ($million/yr)Operations (Labor) 1.5 1.5 1.5 1.5 1.5 1.5 1.8 1.8 1.8 1.8 1.8 1.8Maintenance 5.1 5.3 5.3 5.8 6.3 6.8 7.7 7.9 8.0 13.3 13.7 16.2Pump Stations Power 0.02 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.03 0.03 0.03 0.03Chemicals (Plant Upgrades) 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.4 0.4 0.5 0.5 0.5Total Annual O & M 6.6 6.8 6.8 7.3 7.8 8.3 9.5 9.7 9.8 15.1 15.5 18.0Present Worth Cost ($million)Total Capital Cost 897 915 918 963 1013 1065 1137 1208 1214 1941 2004 2336Total O & M Cost 69.7 71.3 71.9 76.9 82.0 87.7 105.0 107.7 108.4 165.2 170.4 192.6Total Present Worth 970 990 990 1040 1100 1160 1250 1320 1330 2110 2180 2530(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-10 Appendix IReceiving Stream Segment: Lower and Middle River Des PeresAlternative: Alternative 2 - Storage Tunnel under Lower and Middle River Des Peres from Lemay Outfall No. 063 to Lemay Treatment Plant18161412108643210Capital Costs ($million)Conveyance (1)267 267 267 267 267 267 267 267 267 267 267 267Tunnel(s)241 250 259 279 299 345 371 578 599 1000 1036 1431Tunnel Pump Station(s) (2)30 33 36 44 50 65 74 84 89 132 139 162Lemay Treatment Plant Upgrades00000111928327380111Construction Subtotal538 550 562 590 616 688 731 957 987 1472 1522 1971Contingency (25%)134.5 137.5 140.5 147.5 154.0 172.0 182.8 239.3 246.8 368.0 380.5 492.8Construction Total673 688 703 738 770 860 914 1196 1234 1840 1903 2464Engineering, Legal, Admin. (20%)135 138 141 148 154 172 183 239 247 368 381 493Total Capital Cost807 825 843 885 924 1032 1097 1436 1481 2208 2283 2957O & M Costs ($million/yr)Operations (Labor) 1.5 1.5 1.5 1.5 1.5 1.8 1.8 1.8 1.8 1.8 1.8 1.8Maintenance 4.6 4.8 5.0 5.4 5.8 7.0 7.8 10.4 10.9 17.4 18.2 23.8Pump Stations Power 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.03 0.03 0.04 0.04 0.04Chemicals (Plant Upgrades) 0.0 0.0 0.0 0.0 0.0 0.4 0.4 0.5 0.5 0.6 0.6 0.6Total Annual O & M 6.1 6.3 6.5 6.9 7.3 8.8 9.6 12.2 12.7 19.2 20.0 25.6Present Worth Cost ($million)Total Capital Cost 807 825 843 885 924 1032 1097 1436 1481 2208 2283 2957Total O & M Cost 64.4 66.3 68.1 72.7 76.9 98.3 106.8 135.1 140.2 210.4 218.9 277.8Total Present Worth 880 900 920 960 1010 1140 1210 1580 1630 2420 2510 3240(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-11 Appendix IReceiving Stream Segment: Lower and Middle River Des PeresAlternative: Alternative 3 - Storage in horseshoe sewers under Forest Park, storage in tunnel under L&M RDP, and local treatment at Macklind Pump Station (Outfall 063)18161412108643210Capital Costs ($million)Conveyance (1)263 263 263 263 263 263 263 263 263 263 263 263Tunnel(s)56 217 225 233 259 310 322 345 557 741 1000 1333Tunnel Pump Station(s) (2)15 20 23 25 36 52 57 63 78 122 131 153Local Treatment Unit11 11 11 11 11 11 11 11 11 11 11 11Storage in Horseshoe Sewers1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3Lemay Treatment Plant Upgrades00000001023627298Construction Subtotal346 512 523 533 570 637 654 693 933 1200 1478 1859Contingency (25%)86.6 128.1 130.8 133.3 142.6 159.3 163.6 173.3 233.3 300.1 369.6 464.8Construction Total433 640 654 667 713 797 818 867 1167 1500 1848 2324Engineering, Legal, Admin. (20%)87 128 131 133 143 159 164 173 233 300 370 465Total Capital Cost520 769 785 800 855 956 981 1040 1400 1800 2217 2789O & M Costs ($million/yr)Operations (Labor) 0.9 0.9 0.9 0.9 1.5 1.5 1.5 1.8 1.8 1.8 1.8 1.8Maintenance 2.6 4.3 4.5 4.7 5.2 6.3 6.5 7.2 10.2 14.5 17.7 22.5Pump Stations Power 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.02 0.03 0.03 0.03Chemicals (Local Treatment Unit) 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01Chemicals (Plant Upgrades) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.3 0.4 0.4 0.4Total Annual O & M 3.5 5.2 5.4 5.6 6.7 7.8 8.0 9.0 12.0 16.3 19.5 24.3Present Worth Cost ($million)Total Capital Cost 520 769 785 800 855 956 981 1040 1400 1800 2217 2789Total O & M Cost 37.2 55.8 57.8 59.4 71.3 82.0 84.6 99.4 130.9 177.7 211.4 262.4Total Present Worth 560 830 850 860 930 1040 1070 1140 1540 1980 2430 3060(1) Conveyance is sized for ultimate conveyance based on peak flows from typical year(2) 18-hour pump out timeENR CCI = 8100Interest Rate = 7%Time Period = 20 yearsLevel of Control (Overflows per Year)I-12 Metropolitan St. Louis Sewer District Combined Sewer Overflow Long-Term Control Plan APPENDIX J Level 3 Alternatives Analysis Cost-Benefit Data This page is blank to facilitate double-sided printing. Appendix JUntreated(MG)Treated5(MG)BOD5 (ton/year)E. coli (M#/yr)TSS (ton/year)varies N/A N/A 4.71 0 0.63 4.7E+07 7.90 100.0% $0.30.000 0.00 0 0.0Untreated(MG)Treated5(MG)BOD5 (ton/year)E. coli (M#/yr)TSS (ton/year)varies N/A N/A 147 0 19.6 1.4E+09 2480 100.0% $24500 0.0 0 01 89.1% $166160 2.1 1.2E+08 272 82.3% $131260 3.5 2.0E+08 443 67.3% $91480 6.4 3.6E+08 814 58.5% $69610 8.1 4.6E+08 1036 49.7% $49740 9.9 5.6E+08 1258 47.6% $46770 10.3 5.8E+08 13010 35.4% $33950 12.7 7.2E+08 16012 29.3% $271040 13.9 7.9E+08 1750 100.0% $1030130 12.2 5.6E+06 1101 93.9% $749125 12.9 7.3E+07 1212 85.7% $3821122 14.2 1.6E+08 1383 75.5% $3536107 14.8 2.8E+08 1514 70.7% $2943103 15.4 3.3E+08 1596 62.6% $215592 15.9 4.2E+08 1708 57.8% $196284 16.1 4.7E+08 17510 51.0% $177275 16.6 5.5E+08 18512 40.1% $1588 5917.3 6.7E+08 198Wet-weather overflow frequency, volume, loadings, and percent reduction estimates are based on typical year (2000) continuous hydraulic model simulations.Baseline conditionsAlternative 1 – Opt 1Table 1 - Cost Benefit Presentation Table - Maline Creek Outfalls 053 & 060(Based on Level 3 Screening Analysis Results)Alternative description(e.g., storage, separation)Estimated Overflow Frequency1Estimated Percent Reduction2Estimated Capital Cost3 $millionEstimated Overflow Volume Estimated Loadings4Inflow ReductionAlternative 2 – Opt 8Alternative 2 – Opt 9Table 2 - Cost Benefit Presentation Table - Maline Creek Outfalls 051 & 052(Based on Level 3 Screening Analysis Results)Estimated Percent Reduction2Estimated Capital Cost3 $millionEstimated Overflow Volume Estimated Loadings4Inflow ReductionEstimated Overflow Frequency1Alternative 2 – Opt 5Alternative 1 – Opt 4Alternative 1 – Opt 5Alternative 1 – Opt 6Alternative 2 – Opt 1Alternative 2 – Opt 2Alternative 2 – Opt 3Alternative 2 – Opt 4Alternative description(e.g., storage, separation)Baseline conditionsAlternative 1 – Opt 1Alternative 1 – Opt 2Alternative 1 – Opt 3Alternative 2 – Opt 6Alternative 2 – Opt 7Alternative 1 – Opt 9Baseline conditions represent current conditions, including the benefits from implementation of Nine Minimum Controls (i.e., baseline untreated overflow volume and loadings would be higher were it not for these controls already implemented by MSD).Alternative 1 consists of: Complete sewer separation of outfalls 053 & 060Alternative 1 – Opt 7Alternative 1 – Opt 8J-1 Appendix J1.2.3.4.5.Alternative 2 consists of: Continued use of the previously-implemented Nine Minimum Controls, I/I control in the sanitary sewer systems tributary to the Maline Drop Shaft, a local storage tank at outfall 052, and a local treatment unit at outfall 051 to treat CSO flows prior to discharge to Maline Creek. Stored flows would be later bled back to the Bissell Point Treatment Plant for secondary treatment.Alternative 1 consists of: Continued use of the previously-implemented Nine Minimum Controls, I/I control in the sanitary sewer systems tributary to the Maline Drop Shaft, and local storage tanks at outfalls 051 & 052 to store overflow volumes to the desired level of control. Stored flows would be later bled back to the Bissell Point Treatment Plant for secondary treatment.Options 1 to 9 consist of: Varying the size of the 2 local storage tanks to achieve the desired level of control (estimated overflow frequency).Estimated number of untreated wet-weather overflows from CSO outfalls to the receiving stream for a typical year.Percent reduction does not include or reflect any wet weather flows currently being captured for treatment at the WWTP.Baseline conditions represent current conditions, including the benefits from implementation of Nine Minimum Controls (i.e., baseline untreated overflow volume and loadings would be higher were it not for these controls already implemented by MSD).Percent of estimated baseline wet-weather CSO discharge volume that is reduced by control alternative.Cost reflects estimated capital cost to address CSO discharge only, and does not include other required collection system improvements. Cost basis = ENR CCI 8100.Estimated loadings from CSOs to the receiving stream (Maline Creek) before and after implementation of additional new controls. Other loadings to receiving waters, including but not limited to runoff from separate storm sewer areas, are not included. Estimated loadings are based on event mean concentrations derived from the CSO Characterization, Monitoring and Modeling program in 1996. Event mean concentrations for the Maline Creek outfalls are 32 mg/l BOD5; 404 mg/l TSS; 500,000 #/100 ml E. coli for the first hour of an event (baseline) and 200,000 #/100 ml for subsequent hours (baseline and overflows). Local treatment efficiency is 30% BOD and 50% TSS removal.Estimated volume of flow treated by primary treatment at a remote treatment location, as opposed to estimated volume stored and routed to the WWTP for treatment.Notes:Wet-weather overflow frequency, volume, loadings, and percent reduction estimates are based on typical year (2000) continuous hydraulic model simulations.Options 1 to 9 consist of: Varying the size of the local treatment unit and local storage tank to achieve the desired level of control (estimated overflow frequency).J-2 Appendix JUntreated(MG)Treated5(MG)BOD5 (ton/year)E. coli (M#/yr)TSS (ton/year)33 N/A N/A 22.3 0.0 2.98 2.4E+08 37.60 100.0%$5.7 0.0 0.00.00 0 0.00 100.0% $20.90.0 0.00.00 0 0.01 97.2% $17.20.6 0.00.08 4.7E+06 1.02 89.7% $11.62.3 0.00.31 1.7E+07 3.93 88.4% $10.92.6 0.00.35 2.0E+07 4.44 78.4% $6.94.8 0.00.64 3.6E+07 8.16 73.6% $5.35.9 0.00.79 4.5E+07 9.98 72.7% $5.16.1 0.00.81 4.6E+07 10.210 71.0% $4.66.5 0.00.86 4.9E+07 10.912 68.0% $3.97.1 0.00.95 5.4E+07 12.00 100.0% $7.90.0 7.40.69 3.2E+05 6.31 92.1% $7.41.8 5.70.76 1.4E+07 7.72 80.4% $6.94.4 3.00.87 3.3E+07 9.93 76.8% $6.95.2 2.30.90 3.9E+07 10.64 75.4% $6.25.5 1.90.91 4.2E+07 10.96 69.4% $4.96.8 0.60.97 5.2E+07 12.08 68.5% $4.77.0 0.40.98 5.3E+07 12.210 67.7% $4.47.2 0.20.98 5.5E+07 12.312 66.8% $4.07.4 0.00.99 5.6E+07 12.5Alternative 2 – Opt 7Alternative 2 – Opt 8Wet-weather overflow frequency, volume, loadings, and percent reduction estimates are based on typical year (2000) continuous hydraulic model simulations.Alternative 1 consists of: Continued use of the previously-implemented Nine Minimum Controls, the separation of 3 separate storm sewers, and relocation of Bissell Point Outfall No. 059 such that it discharges into the Gingras Creek Branch of the Baden Trunk Sewer.Estimated Overflow Frequency1Alternative description(e.g., storage, separation)Baseline conditionsAlternative 1 – Opt 1Alternative 2 – Opt 1Alternative 2 – Opt 2Alternative 2 – Opt 3Alternative 2 – Opt 4Alternative 2 – Opt 5Alternative 2 – Opt 6Cost Benefit Presentation Table - Gingras Creek Outfalls(Based on Level 3 Screening Analysis Results)Bissell Point Outfall 059Outfalls included in this table:Estimated Percent Reduction2Estimated Capital Cost3 $millionEstimated Overflow Volume Estimated Loadings4Inflow ReductionAlternative 2 – Opt 9Alternative 3 – Opt 1Alternative 3 – Opt 2Alternative 3 – Opt 3Alternative 3 – Opt 4Alternative 3 – Opt 5Alternative 3 – Opt 6Alternative 3 – Opt 7Alternative 3 – Opt 8Alternative 3 – Opt 9Alternative 2 consists of: Continued use of the previously-implemented Nine Minimum Controls, the separation of 3 separate storm sewers, and a below-grade storage tank to store overflow volumes from Bissell Point Outfall No. 059 to the desired level of control. Stored flows would be later bled back to the Baden Trunk Sewer for secondary treatment at the Bissell Point Treatment Plant.Options 1 to 9 consist of: Varying the size of a single CSO storage tank to achieve the desired level of control (estimated overflow frequency).J-3 Appendix J1.2.3.4.5. Estimated volume of flow treated by primary treatment at a remote treatment location, as opposed to estimated volume stored and routed to the WWTP for treatment.Notes:Options 1 to 9 consist of: Varying the size of a single CSO treatment unit to achieve the desired level of control (estimated overflow frequency).Baseline conditions represent current conditions, including the benefits from implementation of Nine Minimum Controls (i.e., baseline untreated overflow volume and loadings would be higher were it not for these controls already implemented by MSD). Percent of estimated baseline wet-weather CSO discharge volume that is reduced by control alternative.Cost reflects estimated capital cost to address CSO discharge only, and does not include other required collection system improvements. Cost basis = ENR CCI 8100.Estimated loadings from CSOs to the receiving stream (Gingras Creek) before and after implementation of additional new controls. Other loadings to receiving waters, including but not limited to runoff from separate storm sewer areas, are not included. Estimated loadings are based on event mean concentrations derived from the CSO Characterization, Monitoring and Modeling program in 1996. Event mean concentrations for the Gingras Creek outfalls are 32 mg/l BOD5; 404 mg/l TSS; 500,000 #/100 ml E. coli for the first hour of an event (baseline) and 200,000 #/100 ml for subsequent hours (baseline and overflows). Local treatment efficiency is 30% BOD and 50% TSS removal.Estimated number of untreated wet-weather overflows from CSO outfalls to the receiving stream for a typical year.Percent reduction does not include or reflect any wet weather flows currently being captured for treatment at the WWTP.Alternative 3 consists of: Continued use of the previously-implemented Nine Minimum Controls, the separation of 3 separate storm sewers, and a small CSO treatment unit, with disinfection, to treat overflows from Bissell Point Outfall No. 059 to the desired level of control prior to discharge to Gingras Creek.J-4 Appendix JUntreated(MG)Treated5(MG)BOD5 (ton/year)E. coli (M#/yr)TSS (ton/year)15 N/A N/A 0.8 0 0.21.0E+071.20 100.0% $0.100 0.0 0 0Untreated(MG)Treated5(MG)BOD5 (ton/year)E. coli (M#/yr)TSS (ton/year)varies N/A N/A 6,667 0 1502 6.3E+10 99590 100.0% $4,244 0 0 0 0 01 97.7% $3,464 154 0 35 1.2E+09 2302 92.1% $2,677 526 0 119 4.0E+09 7863 88.1% $2,502 792 0 178 6.0E+09 11834 71.8% $1,727 1878 0 423 1.4E+10 28056 64