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Letter to EPA with Proposed Revision (3/26/13)rai I L-1 March 26, 2013 Metropolitan S1, Louis Sevier District 2350 MdrkdtShoal St_ LOA VO63103 Ph= 31t.703.6200 mwalivklatim Chief, Water Enforcement and Compliance Assurance Branch Water and Wetlands Protection Division U.S. Environmental •Protection Agency - Region 7 11201 Renner Blvd. Lenexa, KS 66219 RE: MSD Proposed Revision of CSO Control Measure Design Criteria: CSO Treatment Unit at Lemay CSO Outfall 063 Greetings: The Metropolitan St. Louis Sewer District ("MSD" or the "District") submits this letter as a request under paragraph 61 of the Consent Decree in case number 4:07-ev 01120-CEJ that the design criteria for a CSO Control Measure listed in Appendix D be revised. MSD requests that the design criteria for the CSO Control Measure: "CSO Treatment Unit at Lemay CSO Outfall 063" be revised to have a control measure title of just "CSO Treatment Unit". This CSO Control Measure is included in Appendix D of the Consent Decrees as a CSO control measure for Lower & Middle River Des Peres. MSD's proposed revision to this CSO Control Measure will continue to provide an Enhanced High Rate Clarification facility with a 100 MGD capacity providing the equivalent of primary clarification, solids/floatables disposal, and disinfection. MSD's proposed revision to this CSO Control Measure will allow the CSO treatment unit to be changed to a new location near the downstream end of the CSO storage tunnel (i.e., near the tunnel dewatering pump station and Lemay WWTP). In essence, the flow that would have been treated by the CSO treatment unit at Lemay CSO Outfall 063 and discharged to the River Des Peres, will now enter the tunnel, be transported to the downstream end, and be treated and discharged at that location. Furthermore, MSD's proposed revision if approved by June 30, 2013 will allow MSD to meet the Critical Milestone Dates specified in Appendix D. Demonstrating good engineering practice, the proposed revision, with the relocation of this treatment unit, will benefit water quality on the receiving streams, allow for greater operation and management efficiencies, improve grit management in the CSO storage system and allow for future facility expandability if required. For these and other reasons outlined in the attached documents MSD believes this proposed revision should be approved by EPA. Enclosed and hereby incorporated with this letter you will find 1) a proposal document providing a detailed explanation of the requested revision along with relevant information demonstrating that the proposed revision reflects good engineering practice and will continue to achieve the Performance Criteria specified in Appendix D for this CSO Control Measure; and 2) a red -lined CHIEF, WATER ENFORCEMENT AND COMPLIANCE ASSURANCE BRANCH WATER AND WETLANDS PROTECTION DIVISION U.S. ENVIRONMENTAL PROTECTION AGENCY - REGION 7 MARCH 26, 2013 PAGE version of relevant portions of the Consent Decree (Appendix D and Appendix E) delineating the requested revisions to the Consent Decree for this proposed revision. MSD would like to help facilitate the quickest resolution of this request as possible in an effort to ensure its ability to meet the Critical Milestone dates specified in Appendix D for this CSO Control Measure. With that being said, MSD would like to schedule a meeting between your office and MSD technical staff to discuss any technical questions you may have and the process moving forward. We will contact your office immediately for help coordinating a meeting. If you should have any questions with regard to this matter, please feel free to contact me. Sincerely gat,K Susan M. Myers General Counsel cc: State of Missouri Department of Natural Resources Missouri Coalition For The Environment Foundation Jon Sprague, MSD Brian Hoelscher, MSD Brad Nevois, MSD CHIEF, WATER ENFORCEMENT AND COMPLIANCE ASSURANCE BRANCH WATER AND WETLANDS PROTECTION DIVISION U.S. ENVIRONMENTAL PROTECTION AGENCY- REGION 7 MARCH 26, 2013 PAGE3 Consent Deem. CUnin111lliLaticf Distribution Lisi United States: Chief, Environmental Enforcement Section Environment and Natural Resources Division U.S. Department of Justice Box 7611 Ben Franklin Station Washington, D.C. 20044-7611 Re: DOJ No. 90-5-1-1-08111 EPA: Chief, Water Enforcement and Compliance Assurance Branch Water and Wetlands Protection Division U.S. Environmental Protection Agency, Region 7 11201 Renner Blvd. Lenexa, KS 66219 David Cozad Regional Counsel Office of Regional Counsel U.S. Environmental Protection Agency, Region 7 901 North 5th Street, Kansas City, KS 66101 State of Missouri: Chief Counsel Agriculture and Environment Division State of Missouri Office of Attorney General 207 W. High Street Jefferson City, MO 65102 Chief, Water Pollution Compliance and Enforcement Section Missouri Department of Natural Resources P.O. Box 176 1101 Riverside Dr. Jefferson City, MO 65101 Director, St. Louis Regional Office Missouri Department of Natural Resources 7523 South Lindbergh Blvd. St. Louis, MO 63125 Coalition: Kathleen Logan Smith Executive Director Missouri Coalition for the Environment 6267 Delmar BIvd. #2E St. Louis, MO 63130 Maxine I. Lipeles Elizabeth J. Hubertz Interdisciplinary Environmental Clinic Washington University School of Law One Brookings Drive Campus Box 1120 St. Louis, MO 63130 MSD: Executive Director Metropolitan St. Louis Sewer District 2350 Market Street St. Louis, MO 63103-2555 General Counsel Metropolitan St. Louis Sewer District 2350 Market Street St. Louis, MO 63103-2555 Director of Engineering Metropolitan St. Louis Sewer District ' 2350 Market Street St. Louis, MO 63103-2555 Metropolitan St. Louis Sewer District Proposed Revision of CSO Control Measure Design Criteria: CSO Treatment Unit at Lemay CSO Outfall 063 In accordance with Paragraph VI.E.61 of Consent Decree No. 4:07-CV-1120 between the United States of America, the Missouri Coalition for the Environment Foundation and Metropolitan St. Louis Sewer District ("MSD") MSD hereby proposes the following revision to the Design Criteria for one of the CSO Control Measures listed in Appendix D of the Consent Decree. For the proposed revision to the design criteria for the CSO Control Measure: Treatment Unit at Lemay CSO Outfall 063, MSD herein demonstrates that the revision 1) reflects good engineering practice, and 2) will continue to achieve the Performance Criteria specified in Appendix D. MSD has also enclosed red -lined versions of relevant portions of the Consent Decree delineating the requested revisions to the Consent Decree for this proposed revision. Overview This proposed revision is for the CSO Control Measure for the Lower & Middle River Des Peres titled CSO Treatment Unit at Lemay CSO 0:4a11063. This control measure can be found on page 6 of Appendix D of the Consent Decree. The location of the treatment unit described in the Consent Decree is depicted in the figure below, at Outfall 063 at the upstream end of the proposed CSO storage tunnel. MSD proposes that the location of the CSO treatment unit be changed to a new location near the downstream end of the CSO storage tunnel (i.e., near the tunnel dewatering pump station and Lemay WWTP). In essence, the flow that would have been treated by the CSO treatment unit at Outfall 063 and discharged to the River Des Peres, will now enter the tunnel. be transported to the downstream end, and be treated and discharged at that location. Current location of CSO Treatment Unit at Outfall 063 0 6,800 13,200 Feet ii Proposed Treatment Facilities /f Proposed Storage Tunnel Under RCP CSO Locations X 'lb Be Separated [] Maddlnd Pump Station ",/ Major Combined Sewers / .J Major Sanitary Sewers /V Skinker-McCauslandTUnnal Creeks �•+ $L Louis City LImits The CSO treatment unit would still be an Enhanced High Rate Clarification facility with a 100 MGD capacity providing the equivalent of primary clarification, solids/floatables disposal, and disinfection. No changes to the Critical Milestones dates (Bid Year and Achievement of Full Operation) are proposed, provided that timely approval of the proposed revision is received. The Proposed Revision Reflects Good Engineering Practice The proposed revision reflects good engineering practice for the following reasons: • Location of the CSO treatment unit nine miles farther downstream along the River Des Peres reduces the impact, if any, of the primary treated and disinfected effluent on the River Des Peres. The relocated facility's discharge point will be at a location where receiving stream flows and stream assimilative capacity are greater. • Location of the CSO treatment unit near or adjacent to the Lemay Wastewater Treatment Plant will provide for significantly improved operations and maintenance (O&M) support compared to a treatment unit at a remote location. O&M issues can be responded to much quicker, and by personnel who specialize in the operation and upkeep of treatment units. The anticipated result is overall better performance of the CSO treatment unit. • Location of the CSO treatment unit at the downstream end of the tunnel will enhance the ability of the tunnel system to effectively deal with grit that enters the system from combined sewers. Some older and relatively -ineffective CSO tunnel designs have emphasized the importance of improving grit management in CSO storage systems by proper pump station design and avoiding "dead -ended" tunnels. • In addition to the water quality and operational issues noted above, a site near the downstream end of the CSO storage tunnel offers several advantages over the site at Outfall 063. The site at Outfall 063 is in close proximity (approximately 500 feet) to Gateway High School. Placing a treatment facility near this school is undesirable from several perspectives: routine chemical deliveries, noise, potential odors, etc. The Outfall 063 site is further complicated by property title issues, and room for future expansion is problematic. Relocating the CSO treatment unit to a site near the downstream end of the tunnel has the advantage of additional land availability, which allows more alternative treatment technologies to be considered, and allows for future facility expandability as recommended by the CSO control policy. The Proposed Revision Will Continue to Achieve the Performance Criteria Specified in Appendix D of the Consent Decree. MSD has determined that this proposed revision will not affect the CSO Control Measure's ability to achieve the Performance Criteria specified in Appendix D of the Consent Decree. Final design of the tunnel system and CSO treatment unit has not yet begun, but preliminary evaluations have been conducted to determine the impacts of relocating the treatment unit on tunnel sizing and CSO control system performance. Several potential impacts were identified as a result of relocating the CSO treatment unit. The intake structure and drop shaft at OutfaIl 063 will need to be nominally larger to accept the additional 100 MGD of flow that otherwise would have been treated and discharged to the River Des Peres channel at this location. Because of the large intake and drop shaft capacity already required for this CSO (conceptual peak design flows of approximately 4,000 MGD), the addition 2 of another 100 MGD of flow is not expected to increase the size or cost of these facilities to a measureable extent. The impact of the additional 100 MGD flow within the tunnel (i.e., during tunnel filling) was also considered, and determined, by practical experience and hydraulic modeling, to be negligible. Finally, impacts on CSO control system performance (i.e., the Performance Criteria) were evaluated. The CSO "control system" is considered as consisting of the storage tunnel and inlet/drop structures, the tunnel dewatering pump station, the CSO treatment unit, and the Lemay WWTP. Because the exact mode of system operation has not yet been determined, pending final design, two hydraulic model runs (using the Long -Term Control Plan's XP-SWMM model) were conducted to "bracket" the performance of the system with the relocated CSO treatment unit. Precipitation data for the typical year (Year 2000) were input, and the model results were then compared to the Performance Criteria specified in the Consent Decree. The two scenarios that were evaluated to bracket system performance are as follows: • The first scenario (Scenario A) considered that the tunnel dewatering pump station would pump whatever volume is available in the tunnel up to a maximum flow rate of 100 MGD. This scenario represents the maximum treatment that the CSO treatment unit would provide. • The second scenario (Scenario B) only pumped flow to the CSO treatment unit when the tunnel was completely filled. This represents the minimum flow that the treatment unit would see. The results of the two (2) bracketing scenarios are presented in the table below, and compared to the Consent Decree performance criteria. Either "extreme" scenario meets the Consent Decree requirements. No increases in tunnel size or treatment unit capacity are needed to accommodate the treatment unit relocation. Performance Criteria Consent Decree Scenario A Scenario B Number of Overflow Events in Typical Year 4 3 4 Untreated Overflow Volume (million gallons) 1,412 980 950 In reality, some intermediate control scheme will be designed wherein the tunnel dewatering pump station will deliver flow either to the Lemay W W TP or the CSO treatment unit during portions of the tunnel filling period to assist with grit transfer through the tunnel, and then the CSO treatment unit would be utilized as necessary to optimize system performance. When the optimal operational scheme is finally developed, additional hydraulic modeling will be performed to define the expected system performance, which is expected to fall between the two scenarios presented above. 3 Conclusion In summary, the proposed revision, the change in the location of the treatment unit represents good engineering practice, and continues to meet the Performance Criteria specified in the Consent Decree. For the reasons outlined above MSD believes that the proposed revision should be made pursuant to paragraph 61 of the Consent Decree. The proposed revision must be made promptly so that MSD can continue to meet the critical milestones identified for this CSO control measure. This document is submitted as MSD's request for EPA approval of this proposed modification. 4 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 1 of 9 PagelD #: 1615 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Control Measures — Maline Creek C5O Canitrol Measure Description Design Criteria Perfo rma nc e Criteria Critical Milestones Elimination of Bissell Point CSO Outfalls 053 and 060 1 CSO Treatment Unit at Bissell Point Outfall 051 Sewer separation to allow elimination of CSO Outfalls Enhanced High Rate Clarification facility Bissell Point Outfall 052 Storage Tank Local storage facility MSI) s Kutes anti Kegulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Draina a Facilities 94 MGD capacity providing equivalent of primary clarification, solids/floatables disposal, and disinfection Provide storage volume of one million gallons, expandable to accommodate storage require- ments, if any, as determined in SSO Control Master Plan Elimination of Bissell Point CSO Outfalls 053 and 060 Reduce overflows to 4 events or less, and 6 million gallons of untreated overflow volume in the typical year('). Comply with applicable Missouri Operating Permit. _ Reduce overflows to 4 events or less, and 20 million gallons of untreated overflow volume in the typical vearrl i • Achievement of Full Operation — 01/01/2011 • Bid Year-2017 • Achievement of Full Operation —12/31 /2020 • Bid Year — 2017 • Achievement of Full Operation —12/31/2020 500 1,000 2,000 Feet • CE Proposed Storage Facility • Proposed Treatment CSO Locations • To Be Separated • Malin Oropshaq Bissell Point Interceptor Tunnel /1/ Major Combined Sewers /\/ Major Sanitary Sewers f'." Creeks *.b St. Louis City Limits Maline Creek CSO Controls Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 2 of 9 PagelD #: 1616 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Control Measures — Gingras Creek CSO C. •trol Measur= Description Design Criteria Perform nee Criteria Critical Milestones Sewer Separation Bissell Point CSO Outfa11 059 Relocation Separation of sewers to reduce stormwater flow Relocation of Outfall 059 from Gingras Creek to branch of Baden Trunk Sewer MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities When incorporated with other Gingras Creek CSO controls, eliminates Outfall 059 to Gingras Creek When incorporated with other Gingras Creek CSO controls, eliminates CSO Outfall 059 to Gingras Creek • Achievement of Full Operation — 06/30/2017 • Achievement of Full Operation — 06/30/2017 „H.lstoT, 500 1,000 2,000 15 Feet 1 Gingras Creek CSO Controls IY "" Proposed Outfall Extension Y New Storm Sewer Alignment C /\/ Major Combined Sewers /N,/ Major Sanitary Sewers N.. Creeks •'. St. Louis City Limits Schools 2 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 3 of 9 PagelD #: 1617 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Control Measures — Upper River Des Peres CSO C. trol Measur i Description Design Criteria Performance Criteria Critical Milestones Upper River Des Peres Storage Tunnel serving Lemay Outfalls 064, 066 to 096, 099 to 102, 167, 178 and 180 Deep storage tunnel, near - surface facilities, pump station, sewer separation and consolida- tion sewers Provide storage volume of 30 million gallons in deep tunnel system to capture flows from Lemay CSO Outfalls 064, 066 to 096, 099 to 102, 167, 178 and 180 When incorporated with other River Des Peres CSO controls, reduce overflows to 4 events or less, and 94 million gallons of untreated overflow volume in the typical year(1) Upper River Des Peres CSO Controls • Bid Year — 2028 • Achievement of Full Operation — 06/30/2034 3 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 4 of 9 PagelD #: 1618 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Control Measures — River Des Peres Tributaries CSO C Measur trot Description Design Criteria Performance Criteria Critical Milestones Elimination of Lemay CSO Outfalls 108, 110, 114, 115, 157, 164 and 165 Lemay CSO Outfall 107 Elimination Lemay CSO Outfall 112 Elimination Lemay CSO Outfall 116 Elimination Lemay CSO Outfall 141 Elimination Sewer separation to allow elimination of CSO Outfalls Sewer separation to allow elimination of Lemay Outfall 107 Sewer separation to allow elimination of Lemay Outfall 112 Sewer separation to allow elimination of Lemay Outfall 116 Sewer separation to allow elimination of Lemay Outfall 141 MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Draina e Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities Lemay CSO Outfall 160 Elimination Lemay CSO Outfall 161 Elimination Lemay CSO Outfall 174 Elimination Lemay CSO Outfall 175 Elimination Sewer separation to allow elimination of Lemay Outfall 160 Sewer separation to allow elimination of Lemay Outfall 161 Sewer separation to allow elimination of Lemay IOutfall 174 Sewer separation to allow elimination of Lemay Outfall 175 MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities Elimination of Lemay CSO Outfalls 108, 110, 114, 115, 157, 164 and 165 • Achievement of Full Operation— 01/01/2011 Elimination of Lemay CSO Outfall 107 Elimination of Lemay CSO Outfall 112 Elimination of Lemay CSO Outfall 116 Elimination of Lemay CSO Outfall 141 Elimination of Lemay CSO Outfall 160 • Achievement of Full Operation —12/31/2012 • Achievement of Full Operation --12/31/2012 • Achievement of Full Operation-12/31/2012 • Achievement of Full Operation— 12/31/2012 • Achievement of Full Operation-12/31/2012 Elimination of Lemay • Achievement of Full CSO Outfall 161 Operation— 06/30/2021 Elimination of Lemay CSO Outfall 174 • Achievement of Full Operation —12/31/2012 MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities Elimination of Lemay CSO Outfall 175 • Achievement of Full Operation —12/31 /2012 4 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 5 of 9 PagelD #: 1619 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Cc}l trol Measur= Description Design Criteria Performance Criteria COO caI iwliiestones River Des Peres Tributaries Storage Tunnel serving Lemay CSO Outfalls 103, 104, 105, 106, 111, 117 to 128, 130, 131, 134, 136 to 140, 166 and 176 Storage / conveyance tunnel, near - surface facilities, pump station, sewer separation and consolidation sewers 0 3,000 0,000 Feel Conveyance tunnel with storage volume of 28 million gallons to capture flows from Lemay CSO Outfalls 103, 104, 105, 106, 111, 117 to 128, 130, 131, 134, 136 to 140, 166 and 176 When incorporated with other River Des Peres CSO controls, reduce overflows to 4 events or less to River Des Peres main channel in the typical yew') • Bid Year— 2024 • Achievement of Full Operation — 06/30/2030 River Des Peres Tributaries CSO Controls a Dewatertng Pump Station ONalf Conveyance! Storage Tunnel ]t[ To Be Separated 71. Eliminated Claps /r/ Major Combined Sewers Major Sanitary Sewers Creaks '••• St. Louis City Limits 5 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 6 of 9 PagelD #: 1620 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Control Measures - Lower & Middle River Des Peres CSO Caritrol Description Measur- Design Criteria Performance Criteria Critical Milestones Elimination of Lemay CSO Outfalls 046; 049, 168 and 177 Lemay CSO Outfall 062 Elimination CSO Treatment Unit COAutfa41.063 In -sewer Storage Upstream of Lemay CSO Outfall 063 Sewer separation to allow elimination of CSO Outfalls Sewer separation to allow elimination of Lemay CSO Outfall 062 Enhanced High Rate Clarification facility Inflatable or moveable dam system to allow flow storage in upstream 29-fl horseshoe sewers MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities 100 MGD capacity providing equivalent of primary clarification, solids/floatables disposal, and disinfection Provide 25 million gallons storage capacity within existing sewer system to capture flows from Lemay CSO Outfall 063 Elimination of Lemay CSO Outfalls 046, 049,168 and 177 Elimination of Lemay CSO Outfall 062 When incorporated with other River Des Peres CSO controls, reduce overflows to 4 events or less in the typical year'). Comply with applicable Missouri O • erating Permit. When incorporated with other River Des Peres CSO controls, reduce overflows to 4 events or less in the ical ear') A' • Achievement of Full Operation - 01 /01 /2011 • Achievement of Full Operation -12/31/2015 • Bid Year - 2027 • Achievement of Full Operation-12/31/2030 • Achievement of Full Operation- 12/31/2030 Lower & Middle River Des Peres Storage Tunnel serving Lemay CSO OuifalIs 008 to 032, 036, 037, 039, 041 to 044, 048, 050, 052, 053, 054, 057, 058, 061, 063, 163, 170 to 173, and 181 Deep storage tunnel, near - surface facilities, pump station, sewer separation and consolida- tion sewers Provide storage volume of 206 million gallons in deep tunnel system to capture flows from Lemay CSO Outfalls 008 to 032, 036, 037, 039, 041 to 044, 048, 050, 052, 053, 054, 057, 058, 061, 063, 163, 170 to 173, and 181 When incorporated with other River Des Peres CSO controls, reduce overflows to 4 events or less in the typical year'), and untreated overflow volume to the River Des Peres of 1,412 million gallons from the Lower & Middle River Des Peres Storage Tunnel and the River Des Peres Tributaries Storage Tunnel combined. • Bid Year- 2021 • Achievement of Full Operation -12/31/2030 6 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 7 of 9 PagelD #: 1621 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones zit.- uN. �rr'+C;�39'.;+i�.. F 4 ,..--ri •1f-_ f ._ -7If j:. - ama i fi .$i49 411477 I- 1 ,.� -'4' ._.1 MOVE TREATMENT UNIT , i.-'r tr j ^ Liemay-163 t \ • E — i ��-Lemay 18 e' . _ s #r'- If *—WL)Eibrol PUMP MITATt6N . e ll'. ' . �.• . " f . 1 • 43.600 13.200 Feet Proposed Trealment Facilities ,e've Proposed Storage Tunnel Under RCP CSO Locations To Be Separated Manktind Pump Station E�3 /\/ Major Combined Sewers /\/ Major Sanitary Sewers Skinker-McCausland Tunnel r Creeks •••,i SL Louis City Limits Lower & Middle River Des Peres CSO Controls 7 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 8 of 9 PagelD #: 1622 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones Other CSO Control Measures CSO Control Description Design Criteria Measure Perforrrtance Criteria Critical Milestones Bissell Point CSO Outfall 055 Elimination Sewer separation to allow elimination of Bissell Point CSO Outfall 055 Lemay Treatment Plant — Increase Secondary Treatment Capacity Lemay Treatment Plant — Utilize Excess Primary Treatment Capacity — Phase I Lemay Treatment Plant — Utilize Excess Primary Treatment Capacity — Phase II Bissell Point Treatment PIant — Utilize Excess Primary Treatment Capacity Upgrade aeration tanks and ancillary systems to achieve peak wet -weather capacity of 210 MGD Increase influent pumping, preliminary treatment and primary treatment capacity from 240 MGD to 290 MGD Increase influent Pumping, preliminary treatment and primary treatment capacity from 290 MGD to 340 MGD Utilize excess 100 MGD preliminary and primary treatment capacity to treat wet weather flows MSD's Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and Stormwater Drainage Facilities 10 CSR 20-8 for new facilities Existing facilities Design Basis 10 CSR 20-8 for new facilities Existing facilities Design Basis 10 CSR 20-8 for new facilities Existing facilities Design Basis 10 CSR 20-8 for new facilities Existing facilities Design Basis Elimination of Bissell Point CSO Outfall 055 • Achievement of Full Operation —01/01/2011 Provide peak wet -weather flow capacity of 210 MGD through secondary treat- ment. Operate treatment facilities to comply with Missouri State Operating Permit requirements. Upon completion of the stress test required by Appendix E, MSD shall operate the WWTP in accordance with the maximum treatable flow rate for each treatment step. Provide peak wet weather flow capacity of 290 MGD through primary treatment when plant flows exceed secondary treatment capacity. Operate treatment facilities to comply with Missouri State Operating Permit requirements. Provide peak wet weather flow capacity of 340 MGD through primary treatment when plant flows exceed secondary treatment capacity. Operate treatment facilities to comply with Missouri State Operating j Permit requirements_ Provide peak wet weather flow capacity of 350 MGD through primary treatment when plant flows exceed secondary treatment capacity and when total plant flow is not limited by river flooding. Operate treatment facilities to comply with Missouri State Operating Permit re uirements. • Achievement of Full Operation— 12/31/2015 • Achievement of Full Operation — 01/01/2011 • Achievement of Full Operation-12/31 /2015 • Achievement of Full Operation — 01/01/2011 8 Case: 4:07-cv-01120-CEJ Doc. #: 159-4 Filed: 04/27/12 Page: 9 of 9 PagelD #: 1623 Appendix D CSO Control Measures, Design Criteria, Performance Criteria, and Critical Milestones CSO Con rol Measur'• Description Design Criteria Performance Criteria Critical Milestones Green Infrastructure Program — Pilot Program Green Infrastructure Program Stormwater retrofitting of abandoned properties in Bissell Point and Lemay service areas Stormwater retrofitting of abandoned properties in Bissell Point and Lemay service areas Capture runoff from existing or future impervious areas on properties and, if possible, adjacent impervious streets and alleys, in accordance with Section 12 of the Long - Term Control Plan. Capture runoff from existing or future impervious areas on properties and, if possible, adjacent impervious streets and alleys, in accordance with Section 12 of the Long - Term Control Plan and the plan for full-scale implementation contained in the Pilot Program Final Report. Apply green infrastructure on 200 to 400 abandoned properties, encompassing 20 to 40 acres, with a total expenditure of at least $3 million. MSD shall submit to EPA and the State for review and for EPA's approval, with a copy to the Coalition, the Pilot Program Final Report. Performance Criteria to be identified in Pilot Program Final Report, with a minimum expenditure of $100 million total which includes the pilot program. • Achievement of Full Operation —12/31/2015 • Achievement of Full Operation — 06/30/2034 CSO Control Measures will be designed to reduce the number of overflows to Maline Creek and the River Des Peres to achieve a Performance Criteria of 4 overflow events or less in the "typical year." The term "overflow event" means an overflow at one or more CSO Outfalls on a receiving stream segment, based on a 6-hour inter -event time, that does not receive the equivalent of primary clarification, solids and floatables disposal, and disinfection, if necessary to meet water quality standards. "Typical year" performance and achievement of Performance Criteria shall be assessed in accordance with the Post -Construction Monitoring Program using the annual statistics generated by the hydraulic model based on the Year 2000 hourly precipitation data from Lambert St. Louis International Airport. 9 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 1 of 6 PagelD #: 1624 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM I. Purpose and Scope No later than one year from Date of Entry, MSD shall submit to EPA and the State for review and for EPA's approval, with a copy to the Coalition, a plan for a Post -Construction Monitoring Program ("PCMP") that (1) demonstrates whether MSD has achieved the Performance Criteria for each CSO Control Measure set forth in Appendix D and (2) assesses and documents the impacts on receiving water quality that result from the implementation of the CSO Control Measures. MSD shall implement the PCMP upon receipt of EPA's written approval of the PCMP Plan. During implementation of the CSO Control Measures, MSD shall not reroute any flows in the Sewer System for the purpose of meeting the Performance Criteria other than those measures consistent with the Long Term Control Plan ("LTCP") or as otherwise approved in writing by EPA. The PCMP shall include the following elements: • Actions to evaluate and document the effectiveness of each CSO Control Measure set forth in Appendix D; • Actions to assess and document the environmental benefits attributable to CSO Control Measures; • A Water Quality Monitoring Plan that details the monitoring schedule, sampling locations, and monitoring procedures to collect data related to the Performance Criteria and the impacts from CSOs on receiving water quality; • Updates and enhancement of the collection system computer models; and • Mechanisms for providing public education and information on the need for implementation of the CSO Control Measures, any water quality improvements, and the progress made in achieving the Performance Criteria. II. Performance Monitoring and Sampling MSD shall conduct performance monitoring and sampling in order to demonstrate that the Performance Criteria for each CSO Control Measure has been satisfied. The monitoring and sampling data must enable comparison of post -construction conditions with baseline conditions determined during the development of the LTCP. MSD shall initiate long-term monitoring of the performance of major constructed facilities upon Achievement of Full Operation of each facility and long-term monitoring of the receiving streams. Major constructed facilities, identified in Appendix D, include pumping station improvements, wet weather storage tanks and conveyance/storage tunnels, expansions and upgrades of existing wastewater treatment facilities, and any approved Enhanced High Rate Treatment facilities planned for the CSS. Long-term monitoring of water quality in the receiving streams must be performed in accordance with the Water Quality Monitoring Plan described below. 1 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 2 of 6 PagelD #: 1625 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM MSD shall periodically evaluate the data it collects in order to document its compliance with the Performance Criteria. Based on such evaluations, MSD may propose modifications of the PCMP to EPA, and shall make such modifications to the PCMP once approved by EPA in writing. MSD has established its baseline collection system conditions through flow and activation monitoring of selected CSO outfalls. MSD shall perform post -construction flow monitoring at approved locations to support analyses demonstrating compliance with the Performance Criteria for each CSO Control Measure. Locations to be monitored in the Lemay service area include Outtall 063 and other outfalls that collectively represent a minimum of 75 percent of the overflow volume in the typical year, and major components of the CSO Control Measures including pump stations, conveyance/storage tunnels and treatment facilities. Locations to be monitored in the Bissell Point service area include remaining CSO outfalls to Maline Creek, and major components of the CSO Control Measures including pump stations, storage tanks and treatment facilities. MSD will select monitoring locations that specifically provide system operational and flow data for calibrating the updated hydraulic models that include the constructed CSO Control Measures, and locations that provide data for evaluating CSO Control Measure performance. Specific locations to be monitored will be identified in the detailed monitoring plans to be developed for the CSO Control Measures as described below. The data shall also support: • Characterization of sewer flow for evaluation of long-term collection system performance. • Collection of information on overflows at CSOs including overflow volume and duration. • Development of a database of flow data for use in future design efforts related to controlling CSOs. • Enhanced operation and maintenance actions to further control wet weather discharges and achieve NPDES permit compliance. • Demonstration of maximum treatable flow rate through each treatment step following the secondary treatment upgrade at Lemay (stress test). Performance monitoring of each CSO Control Measure shall commence within six months of Achievement of Full Operation of that CSO Control Measure. MSD shall submit to EPA and the State for review and for EPA's approval, with a copy to the Coalition, a detailed monitoring plan for each of the following CSO Control Measures one year prior to the applicable Achievement of Full Operation date set forth in Appendix D: 2 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 3 of 6 PagelD #: 1626 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM Maline Creek: • Enhanced High Rate Treatment unit at Outfall 051 • Storage Tank at Outfall 052 Gingras Creek: • Relocation of Outfall 059 Upper River Des Peres: • Storage tunnel to store flows from CSO outfalls to the Upper River Des Peres River Des Peres Tributaries: • Tunnel to convey/store flows to Lemay WWTF Lower and Middle River Des Peres: • Flow storage in 29-ft horseshoe sewers under Forest Park • Enhanced High Rate treatment unitneaf-enitfa14-0 • Removal of secondary treatment bottlenecks at WWTF • Tunnel to convey/store flows to Lemay WWTF Following Achievement of Full Operation of each CSO Control Measure listed in Appendix D, MSD shall conduct activation monitoring at all CSO outfalls addressed by that particular CSO Control Measure to determine the number of activation events at each CSO outfall, and submit the activation information in the Annual Report as set forth in Section VIII of the Consent Decree. Such activation information shall be submitted as an actual number of events. III. Stress Testing of Lemav Treatment Plant MSD shall construct the CSO Control Measure in accordance with the description, design criteria, performance criteria, and critical milestones contained in Appendix D to achieve a minimum secondary treatment design capacity of 210 million gallons per day (MGD) at the Lemay Treatment Plant. The existing preliminary and primary treatment facilities have a design capacity of 340 MGD. Effluent disinfection facilities are currently being designed with a capacity of 340 MGD. MSD shall submit a stress test protocol to EPA and the State for review and for EPA's approval, with a copy to the Coalition, at least 30 days prior to Achievement of Full Operation of the upgraded wastewater treatment facilities. The protocol shall be designed to determine the maximum treatable wet -weather flow rates for each treatment step (preliminary, primary, secondary, and disinfection) at the Lemay Treatment Plant following the completion of the upgrades described above. EPA/MDNR shall review the stress test protocol pursuant to Section VIE of this Consent Decree (Review and Approval Procedures). 3 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 4 of 6 PagelD #: 1627 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM In accordance with that review, and by no later than 365 days after the Achievement of Full Operation of the treatment plant upgrades, MSD shall conduct the approved stress test. The stress test shall be performed to confirm that the peak wet -weather flow capacity of the preliminary treatment, primary treatment, and disinfection facilities is 340 MGD or higher, and that the peak wet -weather flow capacity of the secondary treatment facilities is 210 MGD or higher. MSD shall submit the results of the stress test to EPA and the State for review and for EPA's approval, with a copy to the Coalition, by no later than 400 days after Achievement of Full Operation of the treatment plant upgrades. The results shall include the maximum treatable wet -weather flow rates for each treatment step (preliminary, primary, secondary, and disinfection). EPA/MDNR shall review the stress test results pursuant to Section VII of this Consent Decree (Review and Approval Procedures). Within 60 days after approval of the stress test results, MSD shall submit an application to modify its operating permit to include the approved maximum treatable wet -weather flow rates for each treatment step. Upon issuance of all necessary operating permit modifications, MSD shall operate the Lemay Treatment Plant in accordance with such maximum treatable wet -weather flow rates for each treatment step. MSD shall conduct post -construction monitoring of treatment plant performance to verify the suitability of the approved stress test results. IV. Water Quality Monitorine Plan No later than one year from the Date of Entry, MSD shall submit a Water Quality Monitoring Plan ("WQMP") to EPA and the State for review and for EPA's approval, with a copy to the Coalition. Sampling locations for receiving waters shall include at a minimum the sites used during the development of the LTCP. Data collected by the U.S. Geological Survey, Missouri Department of Natural Resources, Illinois Environment Protection Agency, or other agencies may be utilized for this monitoring if the data are considered by MSD to be of acceptable quality. The WQMP, at a minimum, shall: • Further characterize baseline water quality conditions prior to development and implementation of the CSO Control Measures set forth in Appendix D; • Measure changes in water quality during and after implementation of the CSO Control Measures; and • Assess the impacts of CSOs on the water quality of the receiving stream remaining after the Achievement of Full Operation of each CSO Control Measure. The WQMP shall define the anticipated schedule for monitoring at each sampling location. MSD shall conduct field measurements and collect water quality samples at the approved sampling locations once every two weeks for all parameters except E. coli which shall be collected once every two weeks during the recreation season. Monitoring shall begin within ninety (90) days of EPA's approval of the PCMP and will be conducted at approximately the same time of day, on the same day of the week, at each location, to obtain an appropriate representation of storm event and non-event conditions. Monitoring shall not be delayed because of weather, except for safety 4 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 5 of 6 PagelD #: 1628 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM reasons. The monitoring frequency shall provide data sufficient to calculate a geometric mean E. coli concentration consistent with applicable water quality standards and for tracking long term trends. MSD shall record field measurements for temperature, pH, and dissolved oxygen at each site. Field observations shall also be recorded for floating debris, submerged debris, algal growth/blooms, odor, and recreational use. Samples shall be collected and analyzed for, at a minimum, E. coli. Samples from receiving waters other than the Mississippi River shall also be analyzed for, at a minimum, BOD, ammonia, and total suspended solids. At least 6 months prior to submitting the WQMP, MSD shall submit to EPA and the State for review and for MDNR's approval, with a copy to the Coalition, the Quality Assurance Project Plan (QAPP) to be used in the monitoring plan. The QAPP shall be developed based on the guidance in the following documents: • United States Environmental Protection Agency (EPA), December 2002. Guidance for Quality Assurance Projects Plans, EPA QAIG-5, Washington, DC. • United States Environmental Protection Agency (EPA), November 2002. Guidance on Environmental Data Verification and Data Validation, EPA QA/G-8, Washington, DC. For data collected by the U.S. Geological Survey, Missouri Department of Natural Resources, Illinois Environment Protection Agency, or other agencies, MSD shall submit the applicable agency's QAPP (e.g., Quality -Assurance Plan for Surface -Water Activities of the U.S. Geological Survey, Missouri Water Science Center, October 2007) for MDNR review before that agency's data may be utilized in the monitoring program. V. Rainfall Monitoring MSD shall include rainfall monitoring as an essential component of the PCMP. Detailed analysis of precipitation is necessary to update MSD's hydraulic model as construction activities proceed to fully evaluate compliance with the Performance Criteria. Precipitation data shall consist of total rainfall depth, duration, intensity, and event distribution. Rainfall data shall be compiled and analyzed as part of the PCMP. The source of rainfall data is MSD's network of long-term rain gauges spaced throughout MSD's service area. Rainfall data collected by MSD shall be used for analysis in connection with other post -construction monitoring data. VI. Data Management MSD shall use a Data Management System and associated protocols for the storage, management, retrieval, and analysis of all data used to assess the performance of MSD's CSO Control Measures. 5 Case: 4:07-cv-01120-CEJ Doc. #: 159-5 Filed: 04/27/12 Page: 6 of 6 PagelD #: 1629 APPENDIX E POST -CONSTRUCTION MONITORING PROGRAM VII. Quality Control Quality control and quality assurance procedures and protocols prepared as part of the development of the LTCP must continue to be used for the implementation of the PCMP. MSD shall update the quality control and quality assurance procedures and protocols from time to time as appropriate. All monitoring plans shall incorporate the procedures and protocols available at the time of submittal. VDT. Analysis., Progress Reporting, and Compliance Demonstration MSD shall use the data from the PCMP to evaluate the performance and effectiveness of each CSO Control Measure in complying with the Performance Criteria set forth in Appendix D. Data from the PCMP shall be used to update and improve calibration and verification of MSD's collection system models. The updated collection system models will be used to demonstrate compliance with Performance Criteria as set forth in Appendix D using the 2000 design year used in development of the LTCP. At this juncture, it is assumed that accepted engineering practice at the time the Post -Construction Monitoring Program is conducted will still rely on a hydraulic model similar to those in use today. In the event that accepted practice at the time the Post -Construction Monitoring Program is conducted has changed, MSD will submit an alternate method for approval. MSD shall report the results and progress of the PCMP in the Annual Report as set forth in Section VIII of the Consent Decree. This progress report shall include a summary of CSS Watershed performance to -date, consisting of: • CSO activation and flow monitoring data; • Rainfall data; • Receiving water monitoring results; • Status in achieving the Performance Criteria for each CSO Control Measure; • Updating of collection system hydraulic models to reflect implemented CSO Control Measures. Necessary model modifications, recalibration, and reverification will be indicated and documented; • Identification and documentation of CSO Control Measure deficiencies and performance limitations; and • Identification and documentation of any proposed supplemental remedial CSO Control Measures. 6