HomeMy Public PortalAboutGI Pilot Final Section 1
Metropolitan St. Louis Sewer District
CSO Volume Reduction
Green Infrastructure Program:
Pilot Final Report and Full Implementation Plan
Original Report and Plan – December 31, 2015
Final Revision – April 15, 2016
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
i April 15, 2016
TABLE OF CONTENTS
List of Appendices ................................................................................................................... iii
List of Tables ............................................................................................................................ iv
List of Figures ............................................................................................................................ v
Acronyms and Abbreviations ................................................................................................... vi
Executive Summary ............................................................................................................. ES-1
Work Performed to Date .................................................................................................. ES-1
Full-Scale Green Infrastructure Implementation Plan ..................................................... ES-4
1 Introduction and Background ......................................................................................... 1-1
1.1 MSD Overview ....................................................................................................... 1-1
1.2 Green Infrastructure at MSD ................................................................................... 1-1
1.3 Consent Decree and CSO Long Term Control Plan ............................................... 1-4
1.4 Green Infrastructure Program .................................................................................. 1-4
1.5 Green Infrastructure Pilot Program ......................................................................... 1-5
1.6 Early Action Program .............................................................................................. 1-5
1.7 Description of the CSO Green Infrastructure (GI) Program Area .......................... 1-5
2 Green Infrastructure Pilot Program Implementation .................................................... 2-23
2.1 Introduction ........................................................................................................... 2-23
2.2 Pilot Summary ....................................................................................................... 2-23
2.3 Pilot Program Requirements ................................................................................. 2-26
2.4 MSD / Land Reutilization Authority (LRA) Agreement ...................................... 2-27
2.5 Pilot Program Administration ............................................................................... 2-27
2.6 Categories of Green Infrastructure Practices ........................................................ 2-28
2.7 Facility Types ........................................................................................................ 2-29
2.7.1 Site-scale Facilities ........................................................................................ 2-29
2.7.2 Neighborhood-scale Facilities ....................................................................... 2-29
2.7.3 Direct vs. Indirect Projects ............................................................................. 2-29
2.8 Demolitions and Deed Recorded Agreements ...................................................... 2-30
2.9 Site Selection ......................................................................................................... 2-34
2.10 Evaluation of Site Selection Methodology ............................................................ 2-40
2.11 Facility Design and Construction .......................................................................... 2-41
2.11.1 Design Approach ........................................................................................... 2-41
2.11.2 Site-scale Facilities ........................................................................................ 2-42
2.11.3 Neighborhood-scale Facilities ....................................................................... 2-47
2.11.4 Design and Construction Lessons Learned .................................................... 2-52
2.12 Post-construction Inspection and Maintenance ..................................................... 2-55
2.13 Public Education and Outreach ............................................................................. 2-62
2.14 Potential Community Benefits .............................................................................. 2-76
2.15 Monitoring ............................................................................................................. 2-77
2.16 Annual Reports ...................................................................................................... 2-81
2.17 Project Accounting ................................................................................................ 2-82
2.18 Conclusions ........................................................................................................... 2-83
3 Performance Evaluation ............................................................................................... 3-84
3.1 Performance Considerations ................................................................................. 3-84
3.2 Initial Performance Estimate ................................................................................. 3-86
3.3 Hydraulic and Hydrologic Modeling .................................................................... 3-86
3.4 Evaluation of Performance Criteria and Metrics ................................................... 3-88
3.5 CSO Volume Reduction for Pilot Projects ............................................................ 3-89
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ii April 15, 2016
4 Early Action Program ................................................................................................... 4-91
4.1 Introduction ........................................................................................................... 4-91
4.2 Early Action Program Requirements .................................................................... 4-91
4.3 Indirect Projects: Early Action Grants .................................................................. 4-91
4.4 Direct Projects: MSD Acquired Neighborhood-scale Facilities ......................... 4-101
4.5 Education and Outreach: Rainscaping Small Grants Program ............................ 4-101
4.6 Findings and Results ........................................................................................... 4-105
5 Green Infrastructure Program Full Implementation Plan ........................................... 5-111
5.1 Introduction ......................................................................................................... 5-111
5.2 CSO Green Infrastructure Program Requirements .............................................. 5-111
5.3 Selection of Green Infrastructure Types and Program Components ................... 5-111
5.4 Program Components .......................................................................................... 5-116
5.4.1 Indirect Projects ........................................................................................... 5-116
5.4.2 Demolitions .................................................................................................. 5-118
5.4.3 Direct Projects .............................................................................................. 5-120
5.4.4 Cityshed Mitigation Program ....................................................................... 5-121
5.4.5 Project Selection Ranking ............................................................................ 5-122
5.4.6 Operations and Maintenance ........................................................................ 5-122
5.4.7 Public Education and Outreach .................................................................... 5-123
5.4.8 Other Green Infrastructure Activities .......................................................... 5-125
5.5 CSO Volume Reduction Green Infrastructure Program Action Plan ................. 5-127
5.5.1 Near Term Action (2016 – 2020)................................................................. 5-127
5.5.2 Long Term Action (2021 – 2034) ................................................................ 5-132
5.5.3 Adaptive Management ................................................................................. 5-132
5.6 Projected CSO Volume Reduction ...................................................................... 5-133
5.7 CSO Control Measure “Green Infrastructure Program” Performance Criteria ... 5-136
6 Green Infrastructure Program Administration & Management .................................. 6-138
6.1 Program Tracking ................................................................................................ 6-138
6.1.1 Tracking Performance .................................................................................. 6-138
6.1.2 Tracking Expenditures ................................................................................. 6-138
6.2 Green Infrastructure Program Annual Reporting ................................................ 6-139
6.2.1 Status of CSO Control Measure Performance Criteria ................................ 6-139
6.2.2 Final Reporting at Program Completion ...................................................... 6-140
6.3 Conclusions ......................................................................................................... 6-140
Works Cited ....................................................................................................................... 6-141
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
iii April 15, 2016
LIST OF APPENDICES
A. CSO Long-Term Control Plan – Chapter 12
B. CSO Long-Term Control Plan – Appendix Q
C. Consent Decree – Appendix D, Page 9
D. Current and Potential Partners and Stakeholders for Green Infrastructure
E. MSD / Land Reutilization Authority (LRA) Agreement
F. Pilot Demolition List
G. Pilot Maintenance and Development Agreements
H. Green Infrastructure Universe of Technologies Screening Tool Technical Memo (User
Instructions) and Spreadsheet
I. Pilot Site Selection Process
J. Green Infrastructure Facilities Constructed During Pilot
K. Pilot Neighborhood-scale Bioretention Design Calculations
L. Sample Neighborhood-scale Bioretention Operation and Maintenance Manual
M. Monthly Inspection Checklist, Post- Construction Stormwater BMP Annual Maintenance
Report, and Stormwater Management Facility Maintenance Inspection Checklist
N. Pilot Public Education and Outreach Activities
O. Rain Garden and Planter Box Maintenance Brochures
P. Community Rooted Green Infrastructure for Urban Water Improvements Final Report –
U.S. EPA Urban Waters Grant
Q. 2015 Rainscaping Survey Analysis and 2015 Rainscaping Survey Form
R. Community Benefits of Green Infrastructure Literature Review
S. Pilot Monitoring Protocol
T. Work Plan for Double Ring Infiltrometer Testing
U. Double Ring Infiltrometer Testing Results 2015
V. Amended Soils Summary of Inspections
W. Pilot Monitoring Semi-annual Reviews
X. Pilot Annual Reports
Y. Pilot Expenditure Report
Z. Pilot Monitoring Analysis
AA. CSO GI Program Hydrologic and Hydraulic Modeling
BB. Early Action Program – Application Form and Instructions, Priority Ranking Form, Green
Infrastructure Grant Program Agreement executed by MSD, and Grantee BMP Expense
Form
CC. Rainscaping Small Grants Program – Background, Program Guidelines, and Application.
List of Recipients for Model Round and Full Round
DD. Pilot Large Scale Maps
EE. Pilot Monitoring Data
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LIST OF TABLES
Table ES-1 Pilot Facility Summary Table ........................................................................... ES-2
Table ES-2 Early Action Program Summary ....................................................................... ES-2
Table ES-3 Pilot Program Cost Summary ........................................................................... ES-3
Table ES-4 Full Program Cost Summary ............................................................................ ES-3
Table ES-5 Full-Scale CSO GI Program Implementation Plan ........................................... ES-7
Table 1-1 Land Use by Area .................................................................................................. 1-6
Table 1-2 Land Use by Percentage ........................................................................................ 1-7
Table 1-3 Average and Selected St. Louis Rainfall Characteristics ...................................... 1-8
Table 1-4 CSO Outfalls per Region ....................................................................................... 1-9
Table 1-5 City of St. Louis Historic Districts within Program Area ................................... 1-11
Table 1-6 Imperviousness by Type and Area ...................................................................... 1-12
Table 1-7 Imperviousness by Type and Percentage ............................................................ 1-13
Table 2-1 Pilot Program Facility Type Summary ................................................................ 2-23
Table 2-2 Pilot Program Facility Summary ......................................................................... 2-24
Table 2-3 Green Infrastructure Practices Commonly Used ................................................. 2-29
Table 2-4 Use of Parcel with Pilot Funded Demolitions ..................................................... 2-31
Table 2-5 Selected Projects .................................................................................................. 2-39
Table 2-6 Site-scale Rain Gardens and Planter Boxes ......................................................... 2-42
Table 2-7 Amended Soil Sites ............................................................................................. 2-47
Table 2-8 Neighborhood-scale Facility Constructed During the Pilot ................................ 2-48
Table 2-9 Neighboorhood-scale Facility Construction Costs .............................................. 2-53
Table 2-10 Summary of Maintenance and Inspection Responsibilities for Neighborhood-
Scale Facilities ..................................................................................................................... 2-58
Table 2-11 Inspections and Maintenance Activities (prior to October 31,2015) ................ 2-59
Table 2-12 2014 Operations and Maintenance Activities and Costs ................................... 2-61
Table 2-13 Neighborhood Meetings .................................................................................... 2-63
Table 2-14 Pilot Monitoring Locations................................................................................ 2-78
Table 2-15 Pilot Program Expenditures ............................................................................... 2-82
Table 3-1 Efficiency Parameter for CSO Regions ............................................................... 3-87
Table 3-2 Calculated CSO Volume Reduction for Pilot Projects ........................................ 3-90
Table 4-1 Proposed Early Action Program Projects Submitted January 2013 ................... 4-92
Table 4-2 Proposed Early Action Program Projects submitted January 2014 ..................... 4-94
Table 4-3 Proposed Early Action Program Projects submitted January 2015 ..................... 4-96
Table 4-4 Early Action Neighborhood-scale Facilities ..................................................... 4-101
Table 4-5 List of Early Action Green Infrastructure BMP Technologies Receiving MSD Plan
Approval as of June 2015 .................................................................................................. 4-107
Table 4-6 Early Action Projects - CY 2014 Expenditures and CY 2015 (through 9/17/15)
Expenditures ...................................................................................................................... 4-109
Table 4-7 Calculated CSO Volume Reduction for MSD Owned EAP ............................. 4-109
Table 4-8 Calculated CSO Volume Reduction for EAP Owned by Others ...................... 4-110
Table 5-1 Summary of MSD Costs for Pilot Program Green Infrastructure Projects ....... 5-113
Table 5-2 Green Infrastructure Practice Applicability to Full CSO GI Program
Implementation Plan .......................................................................................................... 5-115
Table 5-3 Expected Area to be Managed from Trends over Previous 10 years ................ 5-134
Table 5-4 Estimated CSO Volume Reduction for Cityshed Mitigation Projects .............. 5-135
Table 5-5 Estimated Total Mississippi River CSO Volume Reduction for Typical Year . 5-136
Table 5-6 Performance Criteria Identified for CSO Control Measure……………………5-137
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
v April 15, 2016
LIST OF FIGURES
Figure 1-1 MSD's Service Area and Combined Sewer Area ................................................. 1-1
Figure 1-2 MSD’s Green Infrastructure Program Area ....................................................... 1-14
Figure 1-3 MSD’s Program Area with Land Use ................................................................ 1-15
Figure 1-4 MSD’s Program Area with Impervious Surfaces ............................................... 1-16
Figure 1-5 MSD’s Program Area with Soil Types .............................................................. 1-17
Figure 1-6 MSD’s Program Area with CSO Regions .......................................................... 1-18
Figure 1-7 MSD’s Program Area with Municipalities ........................................................ 1-19
Figure 1-8 MSD’s Program Area with City Wards ............................................................. 1-20
Figure 1-9 MSD’s Program Area with City Neighborhoods ............................................... 1-21
Figure 1-10 MSD’s Green Infrastructure Pilot Program Focus Area .................................. 1-22
Figure 2-1 Pilot Program Facility Locations ....................................................................... 2-25
Figure 2-2 Example of LRA Demolition Property .............................................................. 2-30
Figure 2-3 Demolition Locations ......................................................................................... 2-33
Figure 2-4 GIS Exhibit for Investigating Demolitions ........................................................ 2-35
Figure 2-5 Typical Lot After Demolition ............................................................................ 2-40
Figure 2-6 JeffVanderLou Habitat For Humanity Development ......................................... 2-43
Figure 2-7 Planter Box Section ............................................................................................ 2-44
Figure 2-8 Typical Planter Box Installation in the JeffVanderLou Neighborhood ............. 2-44
Figure 2-9 Rain Garden at 1451 Monroe St......................................................................... 2-45
Figure 2-10 Schematic of Typical Bioretention Cell ........................................................... 2-48
Figure 2-11 Forebay at the N. Sarah Street Rain Garden in The Ville ................................ 2-49
Figure 2-12 Example of a Neighborhood-Scale Pilot Project Grading Plan ....................... 2-49
Figure 2-13 Excavation for a Neighborhood-scale Bioretention Cell ................................. 2-50
Figure 2-14 Clinton Street Rain Garden in Old North ......................................................... 2-50
Figure 2-15 N. Sarah St. Rain Garden in The Ville ............................................................. 2-51
Figure 2-16 N. Vandeventer Ave. Rain Garden in JeffVanderLou ..................................... 2-51
Figure 2-17 Geraldine Ave. Rain Garden in Mark Twain ................................................... 2-51
Figure 2-18 Beacon Ave. Rain Garden in Walnut Park East ............................................... 2-52
Figure 2-19 Warne Ave. Rain Garden in O'Fallon .............................................................. 2-52
Figure 2-20 Intact Foundation at a Neighborhood-scale Facility Site ................................. 2-54
Figure 2-21 Permeable Alley Before and After Sweep ....................................................... 2-59
Figure 2-22 Neighborhood-scale Faciltiy Educations Sign ................................................. 2-64
Figure 2-23 Typical Rain Garden in JVL Neighborhood .................................................... 2-65
Figure 2-24 Typical Planterbox in JVL Neighborhood ....................................................... 2-65
Figure 2-25 Block Party Demonstration at the JeffVanderLou Neighborhood ................... 2-66
Figure 2-26 5 Cities Conference - Tour of Green Infrastructure Projects - Clinton Site ..... 2-70
Figure 2-27 Example Project Clear Facebook Entry ........................................................... 2-71
Figure 2-28 St. Louis Post-Dispatch Article, December 30, 2011 ...................................... 2-72
Figure 4-1 Proposed Early Action Grant Projects Submitted January 2013 ....................... 4-93
Figure 4-2 Proposed Early Action Grant Project Submitted January 2014 ......................... 4-95
Figure 4-3 Proposed Early Action Grant Projects Submitted January 2015 ....................... 4-97
Figure 4-4 Soulard Co-op Garden – Lawn Alternative ..................................................... 4-103
Figure 4-5 St. Matthew the Apostle Church - Rain Garden .............................................. 4-104
Figure 4-6 St. Elizabeth Mother of John the Baptist Church - Rain Barrels ..................... 4-104
Figure 4-7 Clyde C. Miller Career Academy – Rain Garden ............................................ 4-105
Figure 5-1 Potential Properties for Targeted Partnerships ................................................. 5-129
Figure 5-2 City of St. Louis Blocks with LRA Properties ................................................. 5-131
Figure 5-3 Initial CSO GI Program Plan ........................................................................... 5-133
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
vi April 15, 2016
ACRONYMS AND ABBREVIATIONS
Acronym /
Abbreviation Definition
BMP Best Management Practices
BSM Bioretention Soil Mix
Cityshed Program Cityshed Mitigation Program
CD Consent Decree
CDA Community Development Administration (City of St. Louis)
CSO Combined Sewer Overflow
CSS Combined Sewer System
CY Calendar Year
DCWA Deer Creek Watershed Alliance
DEC MSD’s Division of Environmental Compliance
EAP Early Action Program
EPA or USEPA United States Environmental Protection Agency
EWRI Environmental Water Resources Institute
GI Green Infrastructure
GI Plan Green Infrastructure Plan
CSO GI Program CSO Volume Reduction Green Infrastructure Program
CSO GI Program Area CSO Volume Reduction Green Infrastructure Program Area
GIS Geographic Information System
IWS Internal Water Storage
JVL JeffVanderLou
LRA Land Reutilization Authority (City of St. Louis)
LTCP Long-Term Control Plan
MBG Missouri Botanical Garden
MEP Maximum Extents Practicable
MS4 Municipal Separate Storm Sewer System
MSD or District Metropolitan St. Louis Sewer District
MSD Rules Metropolitan St. Louis Sewer District Rules and Regulations
and Engineering Design Requirements for Sanitary Sewer and
Stormwater Drainage Facilities
NRCS National Resources Conservation Service
NSO Neighborhood Stabilization Officer
PDA Planning & Urban Design Agency (City of St. Louis)
Pilot CSO Volume Reduction Green Infrastructure Pilot Program
Pilot Focus Area CSO Volume Reduction Green Infrastructure Pilot Program
Focus Area
ROW Right of Way
SEC Project Clear Stakeholder Engagement Committee
SIUE Southern Illinois University Edwardsville
Section 319 Grant MDNR’s Section 319 Grant
SLDC St. Louis Development Corporation
SOV Schedule of Values
SWMP St. Louis County Phase II Stormwater Management Plan
WQv Water Quality Volume
WWTF Wastewater Treatment Facility
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ES-1 April 15, 2016
EXECUTIVE SUMMARY
The Metropolitan St. Louis Sewer District (MSD) has prepared this report to comply with a
Consent Decree (CD) between the United States of America, the Missouri Coalition for the
Environment Foundation and MSD, in the matter of The United States, et al. v. The
Metropolitan St. Louis Sewer District, No. 4:07-CV-1120 (E.D. Mo.). The CD has an Effective
Date of April 27, 2012.
Under the CD, MSD agreed to conduct a $100 million CSO Volume Reduction Green
Infrastructure Program (CSO GI Program) as a Combined Sewer Overflow (CSO) Control
Measure. The primary objective of the CSO GI Program is to reduce CSO Volumes for the
combined sewer outfalls that discharge directly to the Mississippi River. The CSO GI Program
began with the CSO Volume Reduction Green Infrastructure Pilot Program (Pilot) in 2011. The
CSO GI Program will be completed by no later than June 30, 2034.
Requirements for the CSO GI Program are outlined primarily in Section 12 and Appendix Q of
MSD’s Combined Sewer Overflow Long-Term Control Plan (LTCP, 2011). A copy of these two
sections of the LTCP can be found in Appendix A and B, respectively. The full LTCP can be
found on MSD’s website at www.stlmsd.com.
The purpose of this report is twofold:
1. Describe the work performed and the results achieved from the Pilot from 2011 through
2015, and
2. Based upon the results of work completed to date, outline MSD’s Green Infrastructure
Plan (GI Plan), which will describe how the remainder of the $100 million for the full-
scale implementation of the CSO GI Program will be spent.
The CSO GI Program is being implemented in an approximately 43 square mile portion of
MSD’s Combined Sewer System. This area of the Combined Sewer System is directly tributary
to the Mississippi River and is located mostly in the City of St. Louis, with a small portion in St.
Louis County. See Figure 1-2, at the end of Section 1, for a map of the CSO Volume Reduction
Green Infrastructure Program Area (CSO GI Program Area).
Work Performed to Date
Green Infrastructure Pilot Program
The Pilot is an initial 5-year program using $3 million from the $100 million CSO GI Program,
with the objective of testing and resolving the numerous anticipated regulatory, logistical and
financial aspects of the projects among multiple stakeholders. In the Pilot, MSD constructed a
variety of GI projects, monitored selected projects to evaluate performance of the CSO GI
controls, and incorporated public education and outreach in order elicit feedback and to gauge
public support.
The work performed and the results achieved during the Pilot could not have been accomplished
without MSD’s partnership with the City of St. Louis’ Land Reutilization Authority (LRA). As a
result of its partnership agreement with LRA, MSD was able to construct GI on property such as
right-of-ways (ROW), parks, municipal buildings, and other areas where MSD could not
otherwise construct GI. As part of that agreement, MSD contributed dollars towards LRA’s
demolition program, which removed 9.4 acres of impervious surface from the CSO GI Program
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ES-2 April 15, 2016
Area. In exchange, MSD was able to use those parcels (or others as agreed to by LRA) to
construct GI facilities for CSO Volume Reduction. Parcels with demolitions also received a deed
recorded development agreement to ensure gains due to the reduction in impervious surface
would be long-lasting and that GI facilities would be constructed at the optimal time during new
development.
MSD constructed 35 GI facilities during the Pilot, as summarized in Table 1.
Facility Type1, 2 Green Infrastructure Practice # of Facilities
Site‐scale Planter Box 13
Site‐scale Rain Garden 3
Site‐scale Amended Soil3 13
Neighborhood‐scale Bioretention 4
Neighborhood‐scale Bioretention with Detention 2
1. Site-scale – Small practices designed to capture runoff from a single lot.
2. Neighborhood-scale – Larger practices designed to capture runoff from multiple lots.
3. Amended soil was done across multiple parcels at five locations. Each parcel is considered a
“facility” for the purpose of this table.
Table ES-1 Pilot Facility Summary Table
MSD monitored selected sites for approximately two years in order to assess runoff volume
reduction due to the various practices. This information helped determine the potential
effectiveness of the practices and provided data to support the methodology laid out for
calculating runoff volume reduction of GI practices in the St. Louis area. In turn, this
information is used to estimate CSO Volume Reduction from the Pilot and provide guidance for
the CSO GI Program. On average, 231,000 gallons of CSO discharge volume is estimated to be
reduced annually for each acre managed by the CSO GI Program.
Early Action Program
With approval from the United States Environmental Protection Agency (EPA), the CSO LTCP
provided MSD with the option to proceed with additional CSO GI implementation during the
Pilot period. Through this process, MSD implemented additional projects and programs, as
summarized in Table 2.
Program/Project Type1, 2 Program/Project Name Notes
Direct Neighborhood‐scale
Bioretention
4 Bioretention
2 Bioretention with Detention
Indirect Early Action Grants
Program
Three rounds of grants submitted
Awarded 21 grants totaling $17
million
Education and Outreach Rainscaping Small Grants
Program
Model round: 7 workshop
attendees; Awarded 8 grants
totaling $19,765
First full round: 127 workshop
attendees; Awarded 51 grants
totaling $135,000
1. Direct Projects – GI facilities are designed, constructed, owned and maintained by MSD
2. Indirect Projects – MSD provides partial or full funding for the design and construction of GI,
but facilities are owned and maintained by others
Table ES-2 Early Action Program Summary
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ES-3 April 15, 2016
Through the Early Action process, MSD was able to further test the regulatory, logistical, and
financial aspects of implementing the CSO GI Program, which was valuable information for
determining the full-scale implementation plan. MSD successfully constructed additional
Neighborhood-scale CSO GI facilities, developed a grant program for incorporating GI into other
public and private redevelopment projects, and developed a small grants program for the purpose
of educating the public about how stormwater impacts the Combined Sewer System and how
they can be a part of the solution by using GI (a.k.a. “rainscaping”) techniques on their own
properties.
Program Results to Date
MSD invested $3.8 million into the Pilot, which included demolitions, design and construction of
the GI facilities, monitoring to assess their performance, and education and outreach. MSD met
the required $3 million expenditure for the Pilot. MSD applied GI to 294 parcels, managing 33
acres, which meets the CD Performance Criteria of 200-400 properties, encompassing 20-40
acres. The estimated CSO Volume Reduction from the Pilot projects and demolitions was 4 MG
during the typical year 2000, as defined in the LTCP, approximately equally split between
demolitions and GI facilities. A summary of the projects and the performance and costs is
included in the Table 3 below for the Pilot, as compared to the CSO LTCP and the Green
Infrastructure performance criteria as found in the CD’s Appendix D. (See Appendix C of this
report for a copy).
Project
Type
GI Type # Drainage
Area
MG CSO
Reduced
GI Cost
Pilot Demolitions 221 23.6 Acres 2 $1,500,000
Pilot Bioretention 6 9.5 Acre 2 $1,250,614
Pilot – site Rain Garden 2 0.1 Acre 0.02 $12,600
Pilot – site Amended Soil 13 ‐ Inconclusive $25,000
Pilot – site Planter Box 13 0.4 Acre 0.05 $39,000
Totals 33 Acre 4 $3,842,198*
Program
Goal
20‐40 Acre $3,000,000
*Includes additional cost items not listed, such as project site selection, monitoring, maintenance, and education.
Table ES-3 Pilot Program Cost Summary
A summary of the Early Action projects and the performance and costs is included in Table 4
below for the Full Program.
Project Type GI Type # Drainage Area MG CSO
Reduced
GI Cost
EA–MSD Bioretention 6 9.2 Acre 1.6 Est $1,840,000
EA ‐Applicants Various 35 4.7 Acre 1.4 $0.9 million
Small Grants Rain Garden 59 ‐‐ $155,000
EA Total 13.9 Acre 3 MG Est $2.8 million
Pilot 33 Acre 4 MG $3,000,000
Total to Date 47 Acre 7 MG Est $5.8 million
Program Goals 405 –500 Acre 90 MG $100 million
Table ES-4 Full Program Cost Summary
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ES-4 April 15, 2016
Full-Scale Green Infrastructure Implementation Plan
Based on the experience gained through the Pilot and Early Action Programs, MSD has
developed a multifaceted plan for the full-implementation of the CSO GI Program for the use of
GI as a control measure for CSO volume reduction at the Mississippi River CSOs.
The primary features of the plan for implementing the CSO GI Program in the future will include
the following, as described in further detail below:
‐ Indirect Projects with Partners
‐ Demolitions
‐ Direct Projects by MSD
‐ Cityshed Mitigation
‐ Education and Outreach
Indirect Projects
Indirect projects are constructed, owned and maintained by others, but are funded by MSD.
There are two major components that fall within this category.
CSO Green Infrastructure Grant Program
MSD will use the foundation developed during the Early Action Programs (EAP) in order to
continue to offer grants for reimbursement similar to the Early Action Grants for CSO Volume
Reduction. Due to lessons learned during the Early Action phase, the new grants program will
attempt to become more accessible to potential projects and limit expenses based on past
experience. MSD budgeted $5,000,000 per year for the CSO GI Program in its 2015 Rate
Change Proposal and those funds will be used to support the implementation of GI in
redevelopment projects within the CSO GI Program Area.
The new GI Grant Program will be offered in two methods: 1) the annual application process
similar to that used during the Early Action phase, and 2) continuously through Development
Review at a rate of up to $3.50 per cubic foot of annual runoff volume reduced (initially), based
on new development plans submitted within the CSO GI Program Area.
Targeted Partnerships
In addition to the grants outlined above, MSD will continue to pursue partnerships with entities
within the CSO GI Program Area that have the greatest potential for large numbers of GI
facilities that will reduce CSO volumes. These entities include various governmental and non-
governmental organizations such as the City of St. Louis; schools and universities; churches and
community centers; Missouri Department of Transportation; East West Gateway Council of
Governments (for regional coordination on transportation and watershed projects and programs);
and Great Rivers Greenway (for coordination on trail and other greenway programs).
Demolitions
Residential, commercial and other similar type buildings within the CSO GI Program Area that
have their roofs directly connected via downspouts to the Combined Sewer System generate
storm water runoff that contributes to CSO discharge volume. By utilizing demolitions to reduce
impervious surfaces such as roof tops and other surfaces, these demolitions can yield long-term
volume reduction when maintained as green space or when runoff is treated through other GI
practices.
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
ES-5 April 15, 2016
Demolitions will be handled in one of two ways during the CSO GI Program:
1. If the demolition is needed in order to construct a GI facility as part of the CSO GI
Program, the cost of that demolition will be included in the cost of that facility.
2. If a demolition is paid for by the CSO GI Program as a “standalone” GI practice, the
parcel will be preserved as permanent green space or the parcel will require a deed
recorded agreement to provide for future impervious surfaces to be treated, as in the
Pilot. MSD will limit the total expenditure on demolition in this category to 15% of the
$100 million program, providing for an additional $13.5 million. These activities will be
coordinated with the City of St. Louis’ planning efforts and its Strategic Land Use Plan.
Direct Projects
Direct GI projects are funded, constructed and maintained by MSD. There are two potential
components that fall within this category.
Neighborhood-scale Facilities
MSD will continue to investigate the potential for further facilities that manage the stormwater
from multiple lots. These facilities are similar to the neighborhood bioretention “rain gardens”
built during the Pilot and Early Action programs. During the Pilot, MSD staff investigated 192
blocks and located 13 viable locations for Neighborhood-scale facilities. Based on that success
rate, there may be some potential for additional facilities on LRA owned properties that MSD
could either purchase at a low cost or pursue other agreements with LRA. MSD will review at
least another 315 blocks and evaluate the remaining LRA properties to determine the feasibility
of constructing additional GI facilities.
MSD Operating Facilities
Although MSD is not a major property owner in the CSO GI Program Area, the District does
have a small number of facilities in the area, including MSD’s main office building and a number
of existing and planned pump stations. These MSD owned properties may be opportunities for
additional GI facilities for CSO Volume Reduction. In addition, MSD operates a number of
existing basins that will be evaluated as opportunities for retrofitting.
Cityshed Mitigation Program
The goal of the MSD Cityshed Mitigation Program (“Cityshed Program”) is to alleviate the
effects of frequent wet weather surcharging of the Combined Sewer System and overland
flooding. MSD plans to spend $230 million in the Combined Sewer area sub-watersheds over
the life of the CD. The Cityshed Program involves voluntary homeowner buyouts of potentially
several hundred properties over the life of the program. This program helps homeowners through
property purchase and relocation. The property effectively converts impervious area to
permanent green space. MSD plans to use the buyout areas for detention basins to store
separated stormwater runoff from streets and control the flow into the Combined Sewer System.
The conversion of impervious area to green space reduces CSO volume. In addition, the
detention of overland stormwater flows in the detention basin significantly reduces CSO volumes
due to the large volume of stormwater stored in the basin. Therefore, CSO volume reduction will
occur as a result of the Cityshed Program. In the LTCP, Section 12 Green Infrastructure
Program, the Hebert Stormwater Detention Basin project was identified, which is part of MSD’s
Cityshed Program.
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ES-6 April 15, 2016
Green Infrastructure on Cityshed Mitigation Program Properties
Through MSD’s Cityshed Program described above, there exists the potential for incorporating
additional GI facilities on properties where overland flood control facilities are not going to be
constructed. For example, MSD can convert buyout properties to green space or bioretention
facilities for those properties found to be unsuitable for flood control structures. When specific
GI practices are constructed on these properties, the CSO volume reduction and expense will be
accounted for under the CSO GI Program.
Education and Outreach
MSD will continue to use the Rainscaping Small Grants program, to fund construction of small
GI practices on private property, as its primary means for education and outreach within the CSO
GI Program Area. The main objective for the Small Grants Program is to encourage the use of
simple rainscaping techniques for the primary purpose of helping the public understand how
stormwater impacts the combined sewer system, and how they can help be a part of the solution
through the use of rainscaping on their properties. Expenditures for this part of the program will
be limited to 4% of the $100 million program. Through the model and full rounds conducted in
2014 and 2015, respectively, the program had 134 participants in detailed workshops with 59
grants awarded. As part of these efforts, MSD was invited to speak at community meetings,
received positive press coverage, and stimulated neighbor-to-neighbor word of mouth
communication efforts. MSD has found the program to be an extremely efficient means and
outlet for public education and outreach and an effective tool for achieving public acceptance and
community buy-in of the CSO GI Program.
Project Clear has a separate website (www.projectclearstl.org) that includes dedicated pages for
the CSO GI Program and Rainscaping Small Grants programs, as well as other information
regarding “rainscaping.” MSD will continue to use these, as well as other means such as the
Stakeholder Engagement Committee (SEC), for disseminating information, informing and
updating the community about the CSO GI Program, and promoting grant opportunities.
CSO Control Measure Performance Criteria
Based on the experience gained during the Pilot, MSD anticipates that the full expenditure of the
$100 million over the life of the CSO GI Program will result in managing approximately 405 to
500 acres of total drainage area contributing to GI practices, including 202 to 250 acres of
impervious area managed within the total drainage area. MSD estimates this expenditure will
achieve a CSO Volume Reduction of 90 to141 MG during the typical year 2000, as identified in
the LTCP. This is within the range estimated in the LTCP and reflects our current cost estimates
for GI engineering and construction at $200,000 to $250,000 per acre treated.
Green Infrastructure Program Management
In this report, MSD will outline MSD’s GI Plan, which will describe how the remainder of the
$100 million for the full-scale implementation of the CSO GI Program will be spent. As part of
the GI Plan, MSD has identified specific action items for the next 5 years of the CSO GI Program
implementation. MSD activities under the CD will result in a total expenditure of $330 million,
including $100 million for GI and $230 million for the Cityshed Program. MSD views the
Cityshed Program as separate from the CSO GI Program, but, the Cityshed Program does contain
components that contribute to achieving CSO volume reduction.
Over time and as action items are implemented, it is expected that conditions may change or new
information may lead to the need to make changes in the CSO GI Program. In order to adjust to
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ES-7 April 15, 2016
changing circumstances and to incorporate a variety of ongoing lessons learned through GI
implementation, an adaptive management approach to the CSO GI Program is proposed.
Adaptive management reviews would occur at approximately five year intervals. Progress on the
CSO GI Program will be reported annually. Both the GI costs and area treated will be reported to
measure progress. Table ES-5 provides a summary of the CSO GI Program with its various
components. The planned expenditures and implementation timeframe are listed as an estimated
range for each of the program components. The CSO GI Program, as presented, is based solely
on current information. The Cityshed Mitigation Program is presented in the table also.
Table ES-5 Full-Scale CSO GI Program Implementation Plan
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1 INTRODUCTION AND BACKGROUND
The purpose of this section is to give a brief overview of MSD, present the regulatory driver for
the CSO Volume Reduction Green Infrastructure Program (CSO GI Program), and outline the
objectives for the CSO GI Program and the CSO Volume Reduction Green Infrastructure Pilot
Program (Pilot). And finally, this section will describe the CSO Volume Reduction Green
Infrastructure Program Area (CSO GI Program Area).
1.1 MSD Overview
MSD is a regional sewer district, formed in 1954, that provides wastewater and stormwater
service to approximately 1.3 million people in a 525-square-mile service area encompassing the
independent City of St. Louis and approximately 80% of St. Louis County, Missouri. The
collection system owned and operated by MSD consists of 9,578 miles of pipe, as of October 16,
2013, 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 the City of St.
Louis and adjoining St. Louis County are served by a combined sewer system containing
approximately 1,806 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.
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, (i.e., the CSO), is
discharged directly to the
Mississippi River or to one of the river’s tributary streams through permitted outfall pipes.
1.2 Green Infrastructure at MSD
For the purpose of this report, “green infrastructure” or “GI” refers to practices that re-direct
stormwater from impervious and pervious surfaces 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.
Figure 1-1 MSD's Service Area and Combined Sewer Area
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As the regional stormwater utility in the City of St. Louis and St. Louis County, MSD has
become a leader in stormwater quality regulation and implementation. MSD is using its
resources to encourage the implementation of GI throughout the District. MSD has led the
development of new stormwater quality management rules and regulations, established a
progressive Municipal Separate Storm Sewer System (MS4) program as described below, and
developed new design guidance for pump stations and tanks to incorporate green infrastructure.
Collaborative partnerships with watershed alliances and with local municipalities have also been
established to continue to promote the use of GI.
This section highlights several areas where MSD is currently involved outside of the CSO GI
Program to encourage the implementation of GI in the City of St. Louis and St. Louis County.
These areas are also considered to be complimentary to the CSO GI Program. Much of the GI
education and outreach conducted by MSD was associated with incorporating GI design into its
stormwater design requirements for new development in 2006. These efforts have helped MSD
form the groundwork for MSD’s approach to GI in the combined sewer area.
MS4 Program
MSD, as the coordinating MS4 authority since 2003, has partnered with 59 municipalities (co-
permittees) to comply with stormwater permit requirements for the St. Louis Metropolitan Small
Municipal Separate Storm Sewer System. Each permit term, the St. Louis County Phase II
Stormwater Management Plan (SWMP) is written by MSD and co-permittees. The purpose of
the SWMP is to improve area water quality by preventing harmful pollutants from being carried
by stormwater runoff into local water bodies.
The SWMP implements a public education program to provide educational material and conduct
outreach activities to educate the public on stormwater quality management and incorporating GI
practices as a tool for effective stormwater quality management. Some of MSD’s outreach and
education activities occurring under the SWMP include:
Conducting presentations on stormwater pollution prevention and GI practices with the use
of the EnviroScape Watershed/Nonpoint Source Model. This model is an interactive tool to
increase awareness of non-point sources of water pollution and the use of GI practices as an
effective tool for stormwater management.
Providing educational information to the public through the MSD webpage including topics
about common GI techniques such as rain gardens and rain barrels, commercial best
management practices (BMPs), and residential BMPs.
Partnering with The Soil & Water Conservation District of St. Louis County, local
governments, and others to launch the Show Me Rain Gardens website. This site is a
regional water quality initiative promoting rain gardens as an effective stormwater treatment
practice.
Providing financial sponsorship to the St. Louis Audubon Society Bring Conservation Home
Program. This program provides on-site assistance to small private landowners and
encourages the use of BMPs for yard waste and installation of rain gardens to management
storm water.
Also, as part of the SWMP, MSD has implemented a Post Construction Stormwater Quality
Management Program to address stormwater quality runoff from new development and
redevelopment projects to reduce pollutants in stormwater runoff from developed property. The
program ensures that stormwater BMPs are in place to prevent or minimize water quality
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impacts. Since implementation of the new water quality BMP requirements in October 2006,
1,095 projects (representing 3,869 stormwater BMPs) have been constructed, permitted for
construction, or are under review by MSD’s Development Review Division. The most
frequently used stormwater BMPs include rain gardens/bioretention (48%) and permeable
pavement (17%). As a supplement to the water quality BMP regulations, MSD developed the
“Stormwater BMP Toolbox”, an online tool to provide guidance on post-construction stormwater
BMPs design, installation, and maintenance.
Deer Creek Watershed Alliance
To help facilitate cleaner and safer water in the Deer Creek Watershed, Missouri Botanical
Garden (MBG) has initiated a Deer Creek Watershed Alliance (DCWA) in partnership with
MSD, Washington University, Great Rivers Greenway and several other organizations and local
municipalities. MBG is recognized throughout the Midwest as a champion of plant science,
sustainability, and green resources. MSD committed to implementing rain gardens or related
plant-based green infrastructure projects as a partner in the DCWA. MSD and MBG have
identified potential sites for rain garden pilot projects from MSD’s list of stormwater capital
improvement projects located within the Deer Creek Watershed.
As a DCWA partner, MSD has constructed several projects and has also provided considerable
financial support in an effort to improve the Deer Creek Watershed. Between 2009 through
2011, MSD designed and constructed rain gardens as part of capital improvement projects in
University City, Brentwood, and Creve Coeur. MSD contributed approximately $300,000
toward the design and construction of these projects. In 2012, MSD agreed to provide financial
assistance in the amount of $200,000 to help fund a homeowner cost-share program to install
plant-based green infrastructure management practices. The DCWA provided reimbursement to
116 property owners who installed plant-based solutions for stormwater management. In 2014,
MSD agreed to provide financial assistance in the amount of $207,500. The work will be
conducted from 2015 – 2017. In addition, MSD will provide an estimated $160,000 in in-kind
green infrastructure-related improvements in three sub-watersheds in Deer Creek.
As an active partner with the DCWA, the City of Frontenac (located in St. Louis County in a
separate sewer area) has developed The City of Frontenac Stormwater Master Plan to encourage
GI. Frontenac’s Stormwater Master Plan recommends the construction of one stormwater BMP
for each proposed new inlet wherever possible. The recommendation is dependent on a property
owner agreement to maintain the BMP. With 100 stormwater BMP’s planned, typical BMP’s
include rain gardens, bioretention basins, and bioswales. MSD has cost-shared on several of
Frontenac’s projects that have included construction of GI.
MSD Owner’s Design Guidance Document for Tanks, Tunnels and Pump Stations
In 2014, MSD staff prepared the MSD Owner’s Design Guidance Document for Tanks, Tunnels
and Pump Stations to provide guidance to standardize the designs of MSD’s SSO storage tanks,
SSO and CSO tunnels, and associated pump stations. The guidance document ensures that MSD
will, at a minimum, comply with the same standards as private development under the MS4
program and further indicates whether certain practices are appropriate regarding the installation
of GI at storage tank and pump station facilities. MSD currently has plans to incorporate GI into
the design of pump stations. One of the pump stations is in the Gaslight Square neighborhood of
St. Louis which is located in the CSO GI Program Area. The Gaslight Square pump station will
be submitted to the United States Environmental Protection Agency (EPA) and the Missouri
Department of Natural Resources (MDNR) as an Early Action Project in January 2016.
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1.3 Consent Decree and CSO Long Term Control Plan
In 1994, EPA issued a CSO Control Policy which required agencies with CSOs to prepare a
Long-Term Control Plan (LTCP). The LTCP had to describe how the agency would: 1) ensure
that if CSOs occur, they are only as a result of wet weather; 2) bring all wet weather CSO
discharge points into compliance with the technology-based and water quality-based
requirements of the Clean Water Act; and 3) minimize the impacts of CSOs on water quality,
aquatic biota, and human health.
MSD prepared and submitted its original CSO LTCP to MDNR in June 1999. In 2007, the State
of Missouri and EPA filed a lawsuit against MSD regarding overflows. The Missouri Coalition
for the Environment later joined the lawsuit as an intervener. Following discussions aimed at
resolving conflicts between state and federal law/regulation, EPA and MDNR requested that
MSD update its original CSO LTCP. In 2011, MSD prepared an updated CSO LTCP report to
describe the development and selection of MSD’s plan for controlling CSOs. MSD’s control
plan included, along with several other components, system wide controls and watershed specific
controls (including GI), illicit connect controls, I/I controls, sewer separation, and storage tunnel
controls. This control plan schedules a 23-year investment in the implementation of the selected
CSO controls.
From 1992 to 2010, MSD spent approximately $2.3 billion to remove more than 300 overflows.
To address the remaining overflows, of which there are fewer than 400, an increase of MSD’s
collection and treatment capabilities is required – an expensive, complicated, and decades-long
task.
In August 2011, the Department of Justice filed a settlement, or Consent Decree (CD), requiring
MSD to spend a minimum $4.7 billion over the following 23 years to address the issue of
overflows and other sewer system improvements. The CD agreement between MSD, EPA, and
the Missouri Coalition for the Environment has been accepted by the United States District
Court, has been entered by the Court, and went into effect on April 27, 2012.
To meet the goals of the CSO LTCP and the CD, MSD has developed a District-wide initiative,
called Project Clear, to address inflow and infiltration, repair and maintain the existing systems,
and plan for the construction of system improvements. Under this initiative, MSD will invest the
agreed upon $4.7 billion over a generation in planning, designing, and building community
rainscaping, system improvements, and an ambitious program of maintenance and repair.
Rainscaping is a term used under the Project Clear initiative as any combination of plantings,
water features, catch basins, permeable pavement, and more that manage stormwater as close as
possible to where it falls, rather than moving it someplace else. GI facilities fall under the term
rainscaping.
1.4 Green Infrastructure Program
The overall objective for MSD’s CSO GI Program is to identify and implement projects and
programs that will significantly reduce CSO volumes and pollutants loading to the Mississippi
River. GI can supplement redevelopment efforts, add green space to cities, increase recreational
opportunities, increase groundwater recharge, improve air quality, increase property values,
enhance urban quality of life, and improve human health. The CSO GI Program focuses on a
Combined Sewer area within St. Louis County and the City of St. Louis. These same areas
represent some of the most economically-distressed portions of the St. Louis community.
Through the CSO LTCP and the CD, MSD has agreed to develop a CSO GI Program which will
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1-5 April 15, 2016
invest $100 million in GI practices to reduce stormwater flows that drain to the Mississippi
River.
With the majority of the CSO GI Program Area being located in the Bissell Point service area,
MSD realized that understanding how GI can be best used in this area was critical. In 2008,
MSD commissioned a preliminary study of GI in the Bissell Point service area to evaluate the
potential for GI to reduce discharges from 11 target CSOs representing approximately 90% of the
total average annual CSO volume from the Bissell Point Combined Sewer System. The study
was used to identify GI techniques that may be applicable in the main Bissell Point CSO
drainage areas. The study also identified potential retrofit opportunities and their potential to
reduce CSO volumes and peak rates.
The study found that the GI techniques that are likely to be most applicable in MSD’s Combined
Sewer System (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 were not recommended as an
effective GI practice.
1.5 Green Infrastructure Pilot Program
The main objective of the Pilot is to inform decision-making for the full scale CSO GI Program.
In general, the Pilot provides a real-life test of the delivery mechanisms needed to execute the
full-scale implementation plan. As MSD prepares to invest $100 million in GI over 23 years, the
first 5-years was dedicated as the pilot phase. The 23-year period was divided into an initial 5-
year $3 million Pilot and then a full-scale program for the remaining 18 years and $97 million.
The Pilot gives MSD the opportunity to plan for anticipated regulatory, logistical, and financial
aspects of the projects among the multiple stakeholders. MSD must submit a report describing
the work completed and evaluate the results to inform the full-scale program implementation.
1.6 Early Action Program
While the core of the Pilot focuses on stormwater retrofitting conducted in partnership with the
City of St. Louis, MSD sought to build partnerships with other municipalities, schools,
community development organizations, and private developers. The goal of these efforts is to
engage with partners and identify joint opportunities to incorporate GI into ongoing programs
and future redevelopment projects.
During the Pilot and as further outlined in the CSO LTCP, there were projects that had been
identified by MSD as high priority projects suitable for early implementation even before the
full-scale program was developed. When MSD identified a project or a group of projects that it
believed was appropriate for early implementation, the District proposed these projects as an
early action project(s) by submitting a written proposal to MDNR/EPA, for approval.
1.7 Description of the CSO Green Infrastructure (GI) Program Area
The drainage areas for combined sewers with overflows directly to the Mississippi River
constitute the area for the CSO GI Program. See Figure 1-2, at the end of Section 1, for a map of
the CSO GI Program Area. The majority of the CSO GI Program Area is located in the Bissell
Point Service Area, with treatment provided by the Bissell Point Wastewater Treatment Facility
(WWTF). The CSO GI Program Area includes a large part of the City of St. Louis, a small
portion of north St. Louis County, and serves a watershed of approximately 43 square miles,
naturally tributary to the Mississippi River. The population of the CSO GI Program Area is
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1-6 April 15, 2016
estimated to be 210,000 based on the 2010 Federal census. The City of St. Louis has lost
population in each of the last six federal census counts.
The median household income for the City of St. Louis was approximately $34,500 in 2013 with
an increase of income of 27% between 2000 and 2013. The median per capita income was
approximately $22,900 in 2013 with an increase of income of 42% between 2000 and 2013.
1.7.1 Physical Geography
Physical geography describes the land use and impervious cover, geology and soils, climate,
topography, and the CSO regions that drain to CSOs along the Mississippi River.
1.7.1.1 Land Use and Imperviousness
Large portions of the CSO GI Program Area are comprised of residential properties, interspersed
with commercial development along the major roadways. Higher concentrations of industrial
and commercial development exist in the areas adjacent to the Mississippi River and in the
corridor along and between Interstate Highways 44 and 64. There are a total of 89,511 parcels of
property within the CSO GI Program Area, including 75,818 residential parcels (comprising 85%
of the total).
Land use for the CSO GI Program Area is based on information from the City of St. Louis and
St. Louis County parcel databases. The land use breakdown based on area is as follows:
Residential 32%
Industrial/Utility 11%
Commercial 20%
Recreational/Park 3%
Institutional 9%
Undeveloped/Misc. 1%
Right-of-way 25%
See Figure 1-3, at the end of Section 1, for land use within the CSO GI Program Area. Broken
down by CSO regions, the land use is as shown in Table 1-1 and Table 1-2.
Table 1-1 Land Use by Area
CSO Region Area (acres) Commercial Industrial/Utility Institutional Recreational/Park Residential Undeveloped/Misc. Right-of-way
Biddle, Chambers South-Benton 1281 410 172 98 10 219 0 371
Central 8415 2266 906 442 358 2295 2 2145
Dakota 270 25 16 46 3 93 0 86
Ferry 648 93 171 77 3 161 0 143
Gimblin 344 35 142 16 0 94 0 58
Harlem Creek 4967 878 612 542 191 1655 52 1038
Humboldt, Baden 4734 411 325 914 197 1835 107 945
Lemay North 1073 137 156 31 8 427 0 314
Louisa, Trudeau, Barton 641 164 156 10 2 132 0 177
Prairie 484 123 84 20 0 136 0 122
Rocky Branch, Salisbury 2782 539 223 152 38 1044 0 785
Southern Arsenal 1813 252 34 33 50 868 1 575
Utah 275 76 58 28 0 10 0 104
Total Area (acres)27730 5411 3055 2407 861 8971 163 6863
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Table 1-2 Land Use by Percentage
The amount of land cover with impervious surfaces has an impact on wet weather runoff
quantities. Approximately 51% of the surface area in the CSO GI Program Area is impervious
based on year 2013 data. See Figure 1-4, at the end of Section 1, for impervious surfaces within
the program area. This compares to 50% impervious in 2005, indicating relatively little change
in impervious area in the past eight years. In aggregate, public impervious surfaces such as
roadways and sidewalks account for approximately 32% of the impervious area. The other 68%
of the area represents private impervious surfaces such as roofs, driveways, parking lots, and
patios. These percentages are based on data from 2013. In 2005, these values were also 32%
and 68%, respectively. Broken down by CSO regions and specific impervious surfaces, the
imperviousness is as shown in Table 1-6 and Table 1-7, located at the end of Section 1.
1.7.1.2 Geology and Soil Types
General soil information for the CSO GI Program Area was ascertained from soil maps provided
by the US Department of Agriculture Natural Resources Conservation Service. The soils in the
CSO GI Program Area are varied but are generally classified as “Urban land - Harvester
complex.” This complex consists of impervious urban land and the intermingled areas of nearly
level to moderately (0 to 9%) sloping, moderately well drained Harvester soils. This complex is
not rated in a hydrologic soil group. Significant portions of the CSO GI Program Area are
classified as urban bottomland or urban upland with 0 to 5% slopes and are also unrated. The
minority remaining soils have hydrologic soil group ratings of C or C/D. These soils have a slow
to very slow infiltration rate when thoroughly wet. Therefore, underdrains are utilized for
bioretention facilities due to the C/D soils, compaction due to development, and significant
rubble and void spaces after demolition on urban land areas. See Figure 1-5, at the end of
Section 1, for soil types within the program area.
Bedrock underlying the St. Louis region consists primarily of Mississippian limestone/dolomite
and Pennsylvanian shale and sandstone. Depth can range from a few feet to over 100 feet. The
upper layers of bedrock are often weathered and fractured.
1.7.1.3 Climate
The climate of the St. Louis area is classified as modified continental with warm summers and
cold winters. Rapid and frequent daily and seasonal changes in the weather are common, since
moist Maritime Tropical, cold Continental Polar, and cool Maritime Polar air masses all affect
the region’s weather. On average, the St. Louis area receives 36.9 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 two inches of water
equivalent falls as snow in an average year keeping soils saturated in winter months.
CSO Region Commercial Industrial/Utility Institutional Recreational/Park Residential Undeveloped/Misc. Right-of-way
Biddle, Chambers South-Benton 32.0%13.4% 7.7%0.8% 17.1%0.0% 28.9%
Central 26.9%10.8% 5.3%4.3% 27.3%0.0% 25.5%
Dakota 9.3%6.1% 16.9%1.2% 34.6%0.0% 31.9%
Ferry 14.3%26.4% 11.9%0.4% 24.9%0.0% 22.1%
Gimblin 10.2%41.2% 4.5%0.0% 27.3%0.0% 16.8%
Harlem Creek 17.7%12.3% 10.9%3.9% 33.3%1.0% 20.9%
Humboldt, Baden 8.7%6.9% 19.3%4.2% 38.8%2.3% 20.0%
Lemay North 12.8%14.5% 2.9%0.8% 39.8%0.0% 29.3%
Louisa, Trudeau, Barton 25.6%24.3% 1.5%0.3% 20.6%0.0% 27.6%
Prairie 25.4%17.3% 4.0%0.0% 28.1%0.0% 25.1%
Rocky Branch, Salisbury 19.4%8.0% 5.5%1.3% 37.5%0.0% 28.2%
Southern Arsenal 13.9%1.9% 1.8%2.8% 47.9%0.0% 31.7%
Utah 27.7%21.0% 10.0%0.0% 3.5%0.0% 37.8%
Percent of Target Area 19.5%11.0% 8.7%3.1% 32.3%0.6% 24.7%
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Precipitation in the St. Louis region is seasonal, with the three winter months, December,
January, and February, being the driest. The spring and early summer months, March through
July, 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.
MSD selected the year 2000 as the year which best represents system-wide annual average
precipitation conditions pursuant to the June 2011, CSO LTCP. Long-term average rainfall
statistics for St. Louis are shown in Table 1-3 and compared to the selected typical year 2000
statistics. The typical year chosen is representative of average precipitation conditions.
Statistic Long‐Term
Average
Year
2000
Annual Rainfall (inches) 36.89 36.84
Total number of events 102 98
# more than 0.1 inches 59 59
# more than 0.5 inches 23 27
# more than 1.0 inches 9 9
# more than 1.5 inches 4 4
largest event (inches) 3.03 3.51
Average intensity (inches/hour) 0.073 0.075
Average event duration (hours) 6.28 6.2
Average time between events (hours)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 1-3 Average and Selected St. Louis Rainfall Characteristics
1.7.1.4 Topography
The CSO GI Program Area is primarily made up of flat to gently-sloping terrain. Adjacent to the
Mississippi River is a flat and fairly narrow floodplain. The Mississippi River floodplain located
north of downtown St. Louis to Maline Creek is protected from high river conditions by a flood
wall. A series of flood wall 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 flood wall and 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 Mississippi River flood plain elevation.
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The typical residential lot in the program area is elevated above the street and stormwater runoff
drains to the street in front and alley in back. Most of the surface streams have been enclosed
with pipe and there are few unobstructed overland flow paths.
1.7.1.5 CSO Regions
There are 54 CSOs within the CSO GI Program Area. The CSOs have been grouped into 13
CSO regions based on hydraulics and geography. The CSO regions are made up of various
individual sewersheds, also known as “citysheds” that drain to CSOs along the Mississippi River.
See Figure 1-6, at the end of Section 1, for the CSO region locations and Table 1-4, below, for a
list of the CSO regions with associated CSO outfalls.
CSO Region CSO Outfalls
Biddle, Chambers South Benton
BP-022, BP-023, BP-024, BP-025, BP-026, BP-027,
BP-028, BP-029, BP-030, BP-031, BP-032, BP-033,
BP-034, BP-035, BP-036, BP-061
Central BP-011, BP-012, BP-013, BP-014, BP-015, BP-016,
BP-017, BP-018, BP-019, BP-020, BP-021
Dakota BP-002, BP-057
Ferry BP-043, BP-044
Gimblin BP-050
Harlem Creek BP-047
Humboldt, Baden BP-048, BP-049
Lemay North L-142, L-143, L-144, L-147, L-179
Louisa, Trudeau, Barton BP-007, BP-008, BP-009, BP-010
Prairie BP-045, BP-046
Rocky Branch, Salisbury BP-037, BP-038, BP-041, BP-042
Southern Arsenal BP-003, BP-004, BP-006
Utah BP-005
Table 1-4 CSO Outfalls per Region
The Central CSO region includes the MSD Cityshed areas of 7th Street, 13th Street, Camp
Springs, Carroll, Compton, Downtown, Euclid, Forest Park, Lesperance, Mill Creek, Miller,
Ohio-Montrose, Rock Springs, Tower Grove-Manchester, and Western Mill Creek.
The Lemay North CSO region is located in the Lemay Service Area, with treatment provided by
the Lemay WWTF. This is the only CSO region in the program area that is not located in the
Bissell Point Service Area. This CSO region includes the MSD Cityshed areas of Catalan,
Fillmore, Quincy, and Stein.
1.7.2 Political Geography
The political geography includes the various political boundaries and interests included in the
CSO GI Program Area. For a brief description of various partners and stakeholders for the CSO
GI Program, see Appendix D.
1.7.2.1 Municipalities
The CSO GI Program Area encompasses several municipalities, including portions of the cities
of St. Louis, Hillsdale, Jennings, Normandy, and Wellston, and all of the cities of Beverly Hills,
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-10 April 15, 2016
Country Club Hills, Flordell Hills, Northwoods, Norwood Court, Pasadena Hills, Pasadena Park,
Pine Lawn, Uplands Park, Velda City, and Velda Village Hills. The remainder of the GI
Program Area is unincorporated St. Louis County. The vast majority of the program area, 89
percent, is located within the city limits of the City of St. Louis. See Figure 1-7, at the end of
Section 1, for municipalities located within the program area.
1.7.2.2 City of St. Louis
The City of St. Louis is comprised of 28 wards, each with a publically elected alderman. Within
the CSO GI Program Area, there are 23 wards, as shown on Figure 1-8, at the end of Section 1.
The Board of Aldermen is the law making body for the City of St. Louis responsible for the
passage of ordinances, including the annual budget. They also have a portion of the budget
under their control for capital improvements in their respective wards. The alderman or
alderwoman can have a large influence over what happens in their respective wards, can be a
valuable partner for communicating with their constituents, and have valuable insight into factors
influencing the viability of GI project.
The City of St. Louis government is divided into various offices, agencies, departments and
divisions. The Board of Public Service includes the Street Department, the Public Utilities
Department, and the Parks, Recreation, and Forestry Department. There is also the Community
Development Administration, the Planning and Urban Design Agency, which includes the
Cultural Resources Office and the Planning Department, and the St. Louis Development
Corporation, including the Land Reutilization Authority (LRA). The Building Division within
the Public Safety Department enforces building codes and issues permits. Coordination with and
approval from these entities is required for development in the City of St. Louis.
1.7.2.3 City of St. Louis Neighborhoods and Historic Districts
The CSO GI Program Area includes parts of 64 of the 79 distinctive neighborhoods comprising
the City of St. Louis. Many of these neighborhoods have very active community organizations
and associations. See Figure 1-9, at the end of Section 1, for the neighborhood boundaries within
the program area. Also contained within the CSO GI Program Area are the City of St. Louis
Historic Districts. Each City of St. Louis Historic District has a unique set of rehabilitation and
design standards that were developed by neighborhood residents. All changes to building
exteriors must be reviewed for compliance with each district’s standards. Some of these districts
within the program area are Certified Local Historic Districts. These certified districts have been
determined by the Department of the Interior to be eligible for the National Register of Historic
Places and have all the benefits of being listed in the Register. See Table 1-5 for a list of the City
of St. Louis Historic Districts. There are also Preservation Review Districts within the CSO GI
Program Area where demolition review is in the public interest. No demolition permit may be
issued without the approval of the Cultural Resources Office if located within a Preservation
Review District in the City of St. Louis.
41XX-43XX Lindell
Benton Park *
Cherokee-Lemp Brewery
Central West End *
Compton Hill *
Fox Park *
Hyde Park *
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-11 April 15, 2016
Lafayette Square
McKinley Heights
North I-44
Shaw Neighborhood *
Soulard *
Union Station
The Ville
* Certified Local Historic District
Table 1-5 City of St. Louis Historic Districts within Program Area
As can be seen, coordination with numerous political entities and interests is required prior to
project construction within the CSO GI Program Area.
1.7.3 CSO GI Pilot Program Focus Area
For the Pilot, the area for the entire CSO GI Program Area was reduced to only include the City
of St. Louis and the area north of Interstate I-64/40. As will be discussed in greater detail in the
following sections, MSD partnered with the LRA in order to find locations for demonstration
projects. Since the LRA is part of the City of St. Louis, the portions of the CSO GI Program
Area outside of the City of St. Louis’s boundary were eliminated. Also, there is a much larger
number of LRA owned parcels in the north part of the City of St. Louis, which is why the focus
for the Pilot was kept north of I-64/40. See Figure 1-10, at the end of Section 1, for a map of the
CSO Volume Reduction Green Infrastructure Pilot Program Focus Area (Pilot Focus Area).
Metropolitan St. Louis Sewer District CSO Volume Reduction Green Infrastructure Program 1-12 April 15, 2016 CSO Region Region Area Commercial Pavement Commercial Roofs Industrial/Utility Pavement Industrial/Utility Roofs Institutional Pavement Institutional Roofs Recreational/Park Pavement Recreational/ Park Roofs Residential Driveways Biddle, Chambers South-Benton 1281 120 11446473811 3 128Central 8415 869 646309217177115 50 7221Dakota 270 13 5431510 0 07Ferry 648 32 144728195 0 010Gimblin 344 17 676821 0 09Harlem Creek 4967 391 21318711711234 21 4122Humboldt, Baden 4734 198 81783010621 18 3171Lemay North 1073 42 293234106 1 027Louisa, Trudeau, Barton 641 75 43783234 0 012Prairie 484 40 16271671 0 07Rocky Branch, Salisbury 2782 153 10162474431 4 161Southern Arsenal 1813 93 92111099 4 157Utah 275 24 142010910 0 01Total (acres) 27730 2066 1373978598552257 101 18733CSO Region Residential Outbuildings Residential Patios Residential Sidewalks Residential Roofs ROW Pavement ROW Driveways ROW Roofs ROW Sidewalks Other/Misc. Total Impervious Biddle, Chambers South-Benton 1 2 114521712 47 18754Central 52 35 79547 1279810 271 71 4963Dakota 3 2 4214300 4 2136Ferry 1 1 3287811 14 20304Gimblin 3 1 3223000 4 2184Harlem Creek 36 13 4436452453 85 100 2375Humboldt, Baden 36 15 3535546361 47 40 1703Lemay North 17 8 1611117132 24 7541Louisa, Trudeau, Barton 4 2 4399711 23 5422Prairie 2 1 3236111 9 11226Rocky Branch, Salisbury 14 11 2518845733 95 18 1316Southern Arsenal 31 20 3524435132 64 13 1050Utah 0 0 022900 4 19142Total (acres) 200 112 2631989 38013127 691 326 14116Table 1-6 Imperviousness by Type and Area
Metropolitan St. Louis Sewer District CSO Volume Reduction Green Infrastructure Program 1-13 April 15, 2016 CSO Region Commercial Pavement Commercial Roofs Industrial/Utility Pavement Industrial/Utility Roofs Institutional Pavement Institutional Roofs Recreational/ Park Pavement Recreational/ Park Roofs Residential Driveways Residential Outbuildings Biddle, Chambers South-Benton 15.9% 15.1% 6.2% 6.3% 5.1% 1.5% 0.5% 0.1% 3.7% 0.1%Central 17.5% 13.0% 6.2%4.4% 3.6% 2.3%1.0% 0.1% 4.4% 1.1%Dakota 9.2% 3.4% 3.2%2.2% 11.2% 7.6%0.2% 0.0% 5.4% 2.0%Ferry 10.6% 4.5% 15.5%9.1% 6.4% 1.8%0.0% 0.0% 3.2% 0.4%Gimblin 9.3% 3.2% 41.3%4.5% 0.9% 0.5%0.0% 0.0% 4.8% 1.7%Harlem Creek 16.5% 9.0% 7.9%4.9% 4.7% 1.4%0.9% 0.2% 5.1% 1.5%Humboldt, Baden 11.6% 4.8% 4.6%1.7% 6.2% 1.2%1.0% 0.2% 10.0% 2.1%Lemay North 7.8% 5.4% 5.9%6.3% 1.8% 1.1%0.3% 0.0% 5.1% 3.2%Louisa, Trudeau, Barton 17.8% 10.2% 18.6%7.5% 0.6% 0.9%0.1% 0.0% 2.9% 1.0%Prairie 17.6% 7.1% 11.8%7.0% 3.0% 0.5%0.0% 0.0% 3.3% 0.8%Rocky Branch, Salisbury 11.6% 7.6% 4.7%3.6% 3.4% 2.3%0.3% 0.1% 4.6% 1.0%Southern Arsenal 8.8% 8.8% 1.1%1.0% 0.8% 0.9%0.4% 0.1% 5.4% 3.0%Utah 16.9% 9.8% 13.9%7.4% 6.6% 6.7%0.0% 0.0% 0.7% 0.0%Percent of total impervious area 14.6% 9.7% 6.9% 4.2% 3.9% 1.8% 0.7% 0.1% 5.2% 1.4%CSO Region Residential Patios Residential Sidewalks Residential Roofs ROW Pavement ROW Driveways ROW Roofs ROW Sidewalks Other/Misc. Total Biddle, Chambers South-Benton 0.3% 1.5% 5.9% 28.8% 0.2% 0.3% 6.2% 2.5% 100.0%Central 0.7% 1.6% 11.0%25.8% 0.2% 0.2%5.5% 1.4% 100.0%Dakota 1.6% 2.7% 15.6%31.3% 0.2% 0.3%2.6% 1.2% 100.0%Ferry 0.4% 1.1% 9.2%25.8% 0.3% 0.2%4.7% 6.6% 100.0%Gimblin 0.4% 1.8% 11.9%16.5% 0.1% 0.1%2.2% 0.8% 100.0%Harlem Creek 0.6% 1.9% 15.3%22.0% 0.2% 0.1%3.6% 4.2% 100.0%Humboldt, Baden 0.9% 2.0% 20.8%27.2% 0.3% 0.1%2.8% 2.4% 100.0%Lemay North 1.5% 2.9% 20.5%31.6% 0.6% 0.4%4.5% 1.2% 100.0%Louisa, Trudeau, Barton 0.5% 0.9% 9.2%23.0% 0.1% 0.2%5.4% 1.3% 100.0%Prairie 0.6% 1.4% 10.1%27.2% 0.3% 0.3%4.1% 5.1% 100.0%Rocky Branch, Salisbury 0.8% 1.9% 14.3%34.7% 0.3% 0.2%7.2% 1.3% 100.0%Southern Arsenal 1.9% 3.3% 23.2%33.5% 0.2% 0.2%6.1% 1.2% 100.0%Utah 0.0% 0.2% 1.2%20.5% 0.1% 0.3%2.5% 13.2% 100.0%Percent of total impervious area 0.8% 1.9% 14.1% 26.9% 0.2% 0.2% 4.9% 2.3% 100.0%Table 1-7 Imperviousness by Type and Percentage
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-14 April 15, 2016
Figure 1-2 MSD’s Green Infrastructure Program Area
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-15 April 15, 2016
Figure 1-3 MSD’s Program Area with Land Use
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-16 April 15, 2016
Figure 1-4 MSD’s Program Area with Impervious Surfaces
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-17 April 15, 2016
Figure 1-5 MSD’s Program Area with Soil Types
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-18 April 15, 2016
Figure 1-6 MSD’s Program Area with CSO Regions
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-19 April 15, 2016
Figure 1-7 MSD’s Program Area with Municipalities
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-20 April 15, 2016
Figure 1-8 MSD’s Program Area with City Wards
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
1-21 April 15, 2016
Figure 1-9 MSD’s Program Area with City Neighborhoods
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
II El
Legend
Pilot Program Focus Area
St_ Louis City
St_ Louis County
Figure 1-10 MSD's Green Infrastructure Pilot Program Focus Area
1-22
April 15, 2016
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
2-23 April 15, 2016
2 GREEN INFRASTRUCTURE PILOT PROGRAM IMPLEMENTATION
2.1 Introduction
This section outlines the implementation and results of the CSO Volume Reduction Green
Infrastructure Pilot Program (Pilot). It starts with a list of the projects completed in the Pilot and
then outlines the implementation process. Results from the monitoring conducted in the Pilot are
found in Section 3.
Although MSD committed to spend $3 million in the Pilot, the total expenditure was
considerably higher in order to maximize construction of green infrastructure (GI). MSD
completed the Pilot as outlined in the CSO Long-Term Control Plan (LTCP), and included the
following:
Using a variety of GI techniques, in partnership with the City of St. Louis’ Land
Reutilization Authority (LRA), to build implementation experience;
Monitoring and evaluating performance of various types of practices; and
Using various methods of public education and outreach in order to inform the
community and solicit input.
The processes and lessons gained have now been documented for use and further adaptation as
MSD moves towards full-scale implementation of the CSO Volume Reduction Green
Infrastructure Program (CSO GI Program).
2.2 Pilot Summary
MSD constructed 35 GI Site-scale and Neighborhood-scale facilities during the Pilot, as
summarized in Table 2-1.
Facility Type1, 2 Green Infrastructure Practice # of Facilities
Site‐scale Planter Box 13
Site‐scale Rain Garden 3
Site‐scale Amended Soil3 13
Neighborhood‐scale Bioretention 4
Neighborhood‐scale Bioretention with Detention 2
1. Site-scale – Small practices designed to capture runoff from a single lot.
2. Neighborhood-scale – Larger practices designed to capture runoff from multiple lots.
3. Amended soil was done across multiple parcels at five locations; each parcel is considered a
“facility” for the purpose of this table.
Table 2-1 Pilot Program Facility Type Summary
Table 2-2, Pilot Program Facility Summary, identifies the Pilot projects by name and provides
the cost, capacity and area treated by the facility, both total area and impervious area. Figure 2-1
shows locations of the facilities constructed during the Pilot. For a larger format version of
Figure 2-1, see Appendix DD, which also shows the locations of parcels with demolitions.
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
2-24 April 15, 2016
Table 2-2 Pilot Program Facility Summary
Facility Type GI Practice Type Facility Address
MSD
Project #
Planting
Completed
Conceptual
Cost When
Identified
Final MSD
Construction
Cost
Designed
Capacity
(CF)
# of
Parcels
Treated
Area
Controlled
(AC)
Design
Impervious
(AC)
Site-scale Planter Box 2956 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2954 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2946 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2944 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2942 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2940 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2945 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2951 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2953 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box 2957 Thomas St. P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box
2944 Sheridan
Ave.P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box
2942 Sheridan
Ave.P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Planter Box
1341 N. Garrison
Ave.P-28660-01 Fall, 2011 $3,000.00 $3,000.00 99 1 0.03 0.03
Site-scale Rain Garden 1451 Monroe St. P-29210-00 Spring, 2012 $3,000.00 $3,550.00 93 1 0.05 0.03
Site-scale Rain Garden 1453 Monroe St. P-29210-00 Spring, 2012 $3,000.00 $3,550.00 64 1 0.04 0.02
Site-scale Rain Garden 835 Harlan Ave. P-29340-00 Spring, 2012 $6,000.00 $5,500.00 76 1 0.04 0.04
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
4228 Warne Av. 11048 Fall, 2011 $2,000.00 $1,600.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
4232 Warne Av. 11048 Fall, 2011 $2,000.00 $1,600.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
4234 Warne Av. 11048 Fall, 2011 $2,000.00 $1,600.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
4238 Warne Av. 11048 Fall, 2011 $2,000.00 $1,600.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
4240 Warne Av. 11048 Fall, 2011 $2,000.00 $1,600.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 4133 Lea Pl. 11048 Fall, 2011 $1,500.00 $1,000.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 4135 Lea Pl. 11048 Fall, 2011 $1,500.00 $1,000.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
3832 Labadie Av. 11048 Spring, 2012 $3,000.00 $3,350.00 N/A N/A N/A N/A
Site-scale
Front – compost
amendment
Rear – aerate and
top dress
3834 Labadie Av. 11048 Spring, 2012 $3,000.00 $3,350.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 3139 N. Sarah St. 11048 Spring, 2012 $1,500.00 $2,000.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 3143 N. Sarah St. 11048 Spring, 2012 $1,500.00 $2,000.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 4021 Glasgow Av. 11048 Spring, 2012 $1,500.00 $2,000.00 N/A N/A N/A N/A
Site-scale Compost
Amendment 4023 Glasgow Av. 11048 Spring, 2012 $1,500.00 $2,000.00 N/A N/A N/A N/A
Neighborhood-
scale
Bioretention w/
Detention 1323 Clinton St. 11157 Fall, 2012 $141,000.00 $184,873.46 4155 14 1.72 1.18
Neighborhood-
scale Bioretention 1801 North Sarah 11778 Spring, 2013 $120,000.00 $123,782.50 5482 34 3.48 1.77
Neighborhood-
scale Bioretention 2812 North
Vandeventer 11778 Spring, 2013 $96,000.00 $114,005.50 3090 16 1.42 0.78
Neighborhood-
scale Bioretention 5099 Geraldine
Avenue 11802 Spring, 2013 $20,000.00 $92,214.86 1205 3 0.42 0.33
Neighborhood-
scale
Bioretention w/
Detention
5479 Beacon
Avenue 11802 Spring, 2013 $101,000.00 $128,355.12 3461 30 1.79 1.02
Neighborhood-
scale Bioretention 4241 Warne
Avenue 11804 Fall, 2013 $46,000.00 $65,287.00 1427 5 0.68 0.46
$600,000.00 $784,818.44 20,340 118 10.0 6.0
Demolition N/A Various 11048 N/A N/A $213,928.00 N/A N/A N/A N/A
Demolition N/A Various 11048 N/A N/A $63,550.00 N/A N/A N/A N/A
Demolition Future Facilit y Various 11048 N/A N/A $1,222,522.00 N/A 176 23.6 15.6
$2,284,818.44 20,340 294 33.6 21.6Pilot Program Project Totals
Project Name
Habitat for
Humanity Planter
Boxes in
JeffVanderLou
Monroe St. Lot-
scale Rain Gardens
in Old North
Demolition Parcels
Used for or
Tributary to Pilot
Facilities
Demolition Parcels
"Swapped" for other
LRA Parcels
Constructed Project Totals
Beacon Ave. Rain
Garden in Walnut
Park East
Warne Ave. Rain
Garden in O’Fallon
Harlan Av. Lot-scale
Rain Garden in
Baden
Site 4
Site 5
Clinton St. Rain
Garden in Old North
N. Sarah St. Rain
Garden in The Ville
N. Vandeventer
Ave. Rain Garden in
JeffVanderLou
Geraldine Ave. Rain
Garden in Mark
Twain
Demolitions with
Development
Agreement with
Reserve Area
Amended
Soil Package
#2
Site 3
Site 2
Amended
Soil Package
#1
Site 1
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
2-25 April 15, 2016
Figure 2-1 Pilot Program Facility Locations
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
2-26 April 15, 2016
It should be noted that in Table 2-2, the amended soil sites do not include drainage area information
because these parcels are also included in the count for demolitions with “Development Agreement
with Reserve Area”, which provides for a future GI facility when the parcel is redeveloped. To
summarize the table, 118 parcels were treated with permanent facilities, with a total drainage area
redirected to GI of 10 acres. In addition, as described in Section 2.8, MSD-funded demolitions
reduced approximately 9.4 acres of impervious surface on LRA properties in the CSO Volume
Reduction Green Infrastructure Program Area (CSO GI Program Area) and a “Development
Agreement with Reserve Area” was recorded for 176 parcels, which provides for a future GI facility
to be funded by MSD when the parcel is redeveloped. These deed restrictions amount to control of
another 23.6 acres, bringing the Pilot total to 33.6 acres, and 294 parcels controlled. The original
estimate as outlined in the CSO LTCP and Consent Decree (CD) Appendix D was 200–400
properties, or 20–40 acres. Therefore, the performance criteria for the Pilot was achieved.
Also, please note on Figure 2-1 that one Site-scale project, the Harlan Avenue Rain Garden, is
shown outside of the CSO GI Program Area. This is due to a refining of the CSO GI Program Area
as the Combined System model was analyzed more carefully in preparation for estimating CSO
Volume Reduction for the Pilot and the CSO GI Program. Although the site does not provide CSO
volume reduction to the Mississippi River directly (since it is just over the drainage boundary to
Maline Creek), there were valuable lessons learned from this project as explained in Section 2.11.
2.3 Pilot Program Requirements
The requirements for the Pilot are outlined in the LTCP. A brief reference is included in Section 12
of the CSO LTCP, but the detailed scope of the Pilot can be found in Appendix Q of the LTCP,
pages Q-3 through Q-5. Refer to Appendices A and B for a copy of the CSO LTCP language.
In summary, the Pilot requirements are to:
Collect information deemed necessary to evaluate and design CSO GI projects, largely
focused on property owned by the LRA;
Work out the logistics for providing GI on LRA-associated properties including planning,
design, construction, maintenance, and monitoring;
Conduct public education and outreach in neighborhoods where GI projects will be
undertaken;
Include a variety of GI practices;
Design the GI projects, including acquiring any necessary property rights;
Bid and construct the GI projects;
Define and provide for long-term maintenance of the GI facilities;
Create a monitoring protocol for the Pilot;
Monitor selected GI projects according to the protocol to determine project effectiveness;
Complete a final report for the Pilot, to include:
o Description of activities during Pilot
o Summary of maintenance and inspection activities
o Evaluation of the effectiveness, implementability, and costs of the GI included in
the Pilot
o Monitoring data and evaluation
o Summary of community reaction and support of GI
Metropolitan St. Louis Sewer District
CSO Volume Reduction Green Infrastructure Program
2-27 April 15, 2016
o Potential community benefits associated with GI
o Evaluation of barriers to GI encountered, with recommendations as appropriate
o Evaluation of opportunities that presented themselves to coordinate installation of
GI more closely with redevelopment activities
o Updated or refined GI design standards
o An analysis of if or how hydrologic and hydraulic models need to be updated,
refined and calibrated to take into account the effects of the CSO GI Program
o Evaluate benefits of the Pilot in terms of CSO activations and discharge volumes;
and
Use the experience gained from the Pilot to inform full-scale implementation of the $100
million CSO GI Program, update the goal of the CSO GI Program in terms of CSO
discharge volumes, and establish performance criteria for measuring progress toward the
CSO GI Program goals. The plan for the CSO GI Program is to be included in the final
report for the Pilot.
2.4 MSD / Land Reutilization Authority (LRA) Agreement
To begin the implementation process, MSD had to secure land to construct Pilot retrofit projects.
Since MSD is not part of the City of St. Louis or St. Louis County government organizations, it does
not own street right-of-way, parks or other public spaces. Therefore, MSD partnered with the LRA
which receives title to all tax delinquent properties not sold at Sheriff sales. The LRA also receives
title to properties through donations. The LRA maintains, markets, and sells these properties and
performs land assemblage for future development. The LRA owns thousands of parcels throughout
the City of St. Louis, the majority located north of I-64 in economically-distressed portions of the
City. In addition, the LRA has a program for demolition of unsafe buildings on properties they own.
The LRA is one of seven economic development authorities under the St. Louis Development
Corporation (SLDC). The SLDC is an umbrella, not-for-profit corporation with the mission of
fostering economic development and growth in the City of St. Louis by stimulating the market for
private investment in the City’s real estate and business development and improve the quality of life
for everyone who lives in, works in, and visits the City of St. Louis.
For MSD’s Pilot Partnership Agreement with the LRA, MSD provided $1.5 million to LRA for their
demolition program. In exchange, MSD was able to use these lots, or others as agreed, to construct
demonstration GI projects. MSD’s partnership with the LRA for implementation of the Pilot was
critical to resolving the logistical and political aspects of locating and constructing demonstration
projects. A copy of the MSD Pilot Partnership Agreement between MSD and LRA can be found in
Appendix E.
2.5 Pilot Program Administration
The Pilot was managed by MSD’s Engineering Department. However, a program of this scale
requires input not only from external partners and stakeholders such as the LRA, but from practically
every department, division, and group within MSD. For example, the Program Planning group
conducted site selection and GIS database development and mapping. The Development Review
group reviewed private GI facility construction. The Project Design group worked on final design of
MSD-owned facilities with assistance from the Right-of-Way/Survey group for survey and recording
of associated deed restriction documents. The Construction Management division performed
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construction inspection of the facilities. The Operations Department also maintained the
neighborhood-scale facilities and added all of the facilities to MSD’s Asset Management system.
The Operations Department was also involved in the monitoring of the facilities by installing,
maintaining, and collecting monitoring data for analysis. MSD’s Public Information group assisted
with information on the websites, press releases, blogs, and other public outreach efforts.
Although MSD has been promoting GI since 2006, as described in Section 1.2, MSD had not
previously owned any GI facilities of the type included in the Pilot. Most of the expertise within the
District was through the Development Review group, as well as the division of Environmental
Compliance who already had processes in place for post-construction inspection. Wherever
possible, existing systems and processes were adapted to incorporate the GI planning, design,
construction, and maintenance. Using these existing systems and processes helped keep the projects
from feeling too “different.” Where additional expertise was needed, outside experts were
incorporated into the process, specifically for environmental assessments of the sites, geotechnical
exploration, landscape design, and plant expertise.
Through the experience of conducting the Pilot, MSD now has processes in place to further
accommodate GI projects.
2.6 Categories of Green Infrastructure Practices
This section provides information related to structural and non-structural GI practices commonly
used, and the particular types of projects which MSD used during the Pilot.
2.6.1 Green Infrastructure Categories
Table 2-3 summarizes practices that are commonly considered “green infrastructure.” Not all of
these practices were used during the Pilot, but are included here because of reference in other parts
of this report.
Green
Infrastructure
Practice
Description
Amended Soil
Soil amendments are any materials, organic or inorganic, that are added to a soil.
Soil amendments increase a soil's infiltration and water retention capacity and add
runoff storage volume.
Bioretention/Rain
Garden
Bioretention basins, commonly referred to as rain gardens, are shallow surface
depressions planted with specially selected native vegetation to treat and capture
runoff. Some are highly engineered with layers of soil, sand, gravel and underdrains
while others are simpler “native soil” rain gardens with limited soil amendments.
Bioswale Bioswales are shallow stormwater channels planted with a variety of grasses,
shrubs, and/or trees to slow, filter, and infiltrate stormwater runoff.
Downspout
Disconnection
Downspout disconnection is the process of separating roof downspouts from the
sewer system and redirecting roof runoff onto pervious surfaces, such as a lawn or
rain garden. This gives the roof runoff the opportunity to infiltrate, reducing the
volume of runoff to the sewer system.
Green Roof Green roofs, also known as vegetated roofs, are vegetated systems placed on roof
surfaces that capture and store rainwater in soil medium.
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Infiltration Trench
Infiltration trenches are subsurface infiltration structures composed of a stone
trench used for stormwater infiltration and conveyance in drainage areas (due to
the generally low permeability of soils in the St. Louis area, rapid infiltration is not
seen as a common practice within the CSO GI Program Area).
Pervious Pavement Pervious pavement combines stormwater infiltration, storage, and structural
pavement consisting of a permeable surface underlain by a storage/infiltration bed.
Planter Box
Planter boxes are containers or enclosed structures located at least partially above
ground and planted with vegetation that captures, filters through soil media, and
may infiltrate or slowly release stormwater runoff.
Rainwater
Harvesting
Rainwater harvesting using cisterns and rain barrels are storage containers designed
to intercept and store runoff from rooftops and other impervious surfaces to allow
for its reuse.
Tree Box
Tree boxes incorporate stone storage areas, in combination with planting soils for
healthy tree growth, providing storage for captured runoff to infiltrate into the soil.
They can be used in ROWs of streets and in public space such as plazas and parks.
Table 2-3 Green Infrastructure Practices Commonly Used
2.7 Facility Types
For the Pilot, MSD constructed two types of GI facilities—Site-scale Facilities and Neighborhood-
scale Facilities.
2.7.1 Site-scale Facilities
“Site-scale” facilities are GI facilities that are designed to capture runoff from a single parcel,
typically from the roof or other impervious area on the property. Occasionally, the facilities are
oversized to capture some runoff from adjacent impervious areas such as streets and alleyways. Just
like all privately owned stormwater management facilities in the Separate Sewer Area regulated by
the MS4 program by MSD, these facilities are constructed within a “reserve area” that is recorded
with the property, as part of a Maintenance Agreement, assigning maintenance responsibility to the
current owner of the property.
2.7.2 Neighborhood-scale Facilities
“Neighborhood-scale” facilities are GI facilities designed to capture runoff from multiple lots as well
as adjacent roadways and alleys. MSD acquired the properties through the agreements with LRA
and owns and maintains these facilities. The facilities are designed for a future redeveloped
condition in the drainage, or tributary area. Therefore, if redevelopment occurs in that area, MSD
will consider the stormwater management provided by the Neighborhood-scale facility in reviewing
the requirements for the development. Therefore, besides being an amenity for the existing
neighborhood, these facilities could provide an incentive for redevelopment due to at least part of the
stormwater management being provided by the facility. Much will depend on the regulations at the
time, as well as the proposed impervious footprint of the new development, and also whether it is
less than what was assumed for in the design.
2.7.3 Direct vs. Indirect Projects
MSD’s GI projects are further defined as “direct” or “indirect” projects. These terms refer more to
the delivery mechanism of a project as opposed to a particular facility type.
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“Direct Projects” are designed, constructed, and maintained directly by MSD, such as the
Neighborhood-scale facilities implemented during the Pilot.
“Indirect Projects” are projects where MSD provides partial or full funding for the design and
construction of the GI but the facilities are owned and maintained by others. The Site-scaled
facilities in the Pilot, other than the amended soil sites, are examples of “indirect projects.”
2.8 Demolitions and Deed Recorded Agreements
The $1.5 million in MSD funding for LRA’s demolition program resulted in the demolition of 221
buildings on 219 LRA owned parcels. The demolitions not only improved safety but removed
impervious surface, much of it directly connected to the combined sewer system. In the CSO GI
Program Area, approximately 9.4 acres of impervious surface was removed. The location of these
demolitions is shown in Figure 2-3, at the end of this Section 2.8 and a tabular listing is shown in
Appendix F. For a larger format map of demolition locations, see Appendix DD.
In addition to an immediate
reduction in the connected
impervious area, MSD was able
to build GI facilities on the
properties or, alternatively, record
deed restrictions against those
properties in order to provide
lasting control for stormwater
volume reduction.
As explained in the next section,
all of the locations within the
CSO Volume Reduction Green
Infrastructure Pilot Program
Focus Area (Pilot Focus Area),
with MSD funded demolitions,
were visited to determine if a GI
facility would be feasible. If not
feasible at that time, MSD created a
“Development Agreement with Reserve Area” that was signed by MSD and LRA, and recorded
against the deed of the property. The development agreement stipulates the following:
MSD review of development plans required
Future downspouts for roof drainage will not be re-connected to the combined sewer system
Sets a maximum area of impervious surface
Specifies a minimum reserve area needed for future MSD funded GI facility to be built when
the lot is re-developed
The demolition properties were handled in one of the following ways:
“MSD Owned” – If the property was considered a desirable location for a Neighborhood-
scale Facility, the property was conveyed to MSD.
Figure 2-2 Example of LRA Demolition Property
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“Tributary Lot Agreement” – If the property drained to a Neighborhood-scale GI Facility, a
Tributary Lot Development Agreement was recorded. This was also true for other LRA-
owned properties in the tributary area, regardless of whether a MSD funded demolition took
place or not.
“Maintenance Agreement” – If a privately owned Site-scale GI facility was constructed, a
Maintenance Agreement was recorded. This was true of all private facilities, regardless of
whether a MSD funded demolition took place or not.
“Development Agreement with Reserve Area” – If the property was in the Pilot Focus Area,
but was not a feasible location for a GI facility at this time, then a Development Agreement
with Future Reserve Area was recorded in order to coordinate construction of a GI facility
when the lot is re-developed.
“Swapped” – As can be seen in Figure 2-2, not all demolition properties fell within the CSO
GI Program Area. If the property was out of the CSO GI Program Area, then MSD’s rights
to the property were “swapped” for a different property in the Pilot Focus Area for
construction of a Neighborhood-scale GI facility, which was then conveyed to MSD, or as a
“Tributary Lot” described below.
A breakdown of the use of the 219 parcels with MSD funded demolition is below:
Use of Demolition Parcel No. of Parcels*
MSD Owned (used for Neighborhood‐scale facility) 5
Tributary Lot Agreement (drains to Neighborhood‐scale facility) 5
Maintenance Agreement (used for Site‐scale facility) 2
Development Agreement with Reserve Area (future facility) 176
Swapped (outside of Program Area) 31
*Number indicates final use of parcel as a result of both the Pilot and Early Action Program as
discussed in Section 6.
Table 2-4 Use of Parcel with Pilot Funded Demolitions
Deed Recorded Agreements
The following is a summary of all of the deed recorded agreement types as a result of the Pilot,
including a few changes incorporated when additional Neighborhood-scale projects were constructed
during the Early Action Program (See Section 4). See Appendix G for examples of the agreement
documents and a complete listing of parcels with agreements.
Tributary Lot Development Agreement (66 recorded agreements)
Used for lots that drain to a Neighborhood-scale facility
MSD review of development plans required
Future downspouts for roof drainage will not be re-connected to the combined sewer system
Sets a maximum area of impervious surface equal to what was used to design the facility
Development Agreement with Future Reserve Area (176 recorded agreements)
On properties with MSD funded demolition but construction of a GI facility now is not
feasible
MSD review of development plans required
Future downspouts for roof drainage will not be re-connected to the combined sewer system
Sets a maximum area of impervious surface
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Specifies a minimum reserve area needed for future MSD funded GI facility to be built when
the lot is re-developed
Maintenance Agreement (16 recorded agreements)
On properties to receive a privately owned GI facility
MSD review of development plans required
Future downspouts for roof drainage will not be re-connected to the combined sewer system
Sets a maximum area of impervious surface equal to what was used to design the facility
Includes a “Reserve Area” exhibit showing the GI facility location
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Figure 2-3 Demolition Locations
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2.9 Site Selection
In order to find viable sites for the Pilot, MSD developed a screening process along with a priority
ranking system. This process identified those parcels most desirable for Neighborhood-scale
projects or Site-scale projects. MSD spent considerable time and effort investigating the demolition
parcels and adjacent vacant LRA parcels on 192 city blocks. Thirteen Neighborhood-scale facilities
were identified as viable and moved forward to design. Of the thirteen facilities, six were
constructed under the Pilot and six were constructed as Early Action projects, as described in Section
4.
2.9.1 Phase 1 Screening
A screening process was used to provide an initial overview for rating all of the city blocks in the
Pilot Focus Area and to determine the most appealing blocks for GI facilities. MSD’s GIS database
was utilized for the Phase 1 Screening.
It was determined that the major factors affecting GI feasibility that could be screened quickly were
open area, impervious area, and habitable buildings. Data fields deemed to be the most important for
the Phase 1 screening were MSD grid number, city watershed, number of LRA-owned properties,
number of MSD funded demolitions, whether there was more than 0.25 acre of contiguous open
space on LRA-owned properties, and whether there were any habitable structures on LRA-owned
property for each city block. Using these fields along with a data field for notes, a Microsoft Access
database was created with a form to collect the data for all of the blocks in the Pilot Focus Area.
ArcGIS and Microsoft Excel were then used to sum the number of LRA-owned parcels, MSD
funded demolitions, and parcels on each city block. An Excel file was exported from GIS that
contained all of the blocks within the Pilot Focus Area with the respective LRA-owned parcels,
MSD funded demolitions, and parcels for each block. This information, along with viewing aerial
photography in GIS, was used to populate the Access database.
The following Phase 1 rating system was developed:
0.1 point for each LRA-owned lots in city block
2 points for each lot with MSD funded demolition
1 point for > ¼ acre of contiguous area of empty and/or MSD funded demolition
4 points if the entire block is vacant
1 point if all of the LRA-owned lots are vacant
This rating system was used to prioritize the city blocks for field investigation.
2.9.2 Use of the “Universe of Technologies”
The “Universe of Technologies” is a spreadsheet created by MSD staff composed of feasible GI
alternatives for the Pilot. The staff’s goal during the site selection process was to visit city blocks
with and without MSD funded demolitions and find LRA-owned parcels where the different
“Universe of Technologies” could be applied.
The list of technologies was derived from staff experience, stormwater design manuals, Center for
Watershed Protection guidance, and other literature. Technologies were then categorized into five
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general response actions: (1) impervious area reduction; (2) collection and discharge (to sewer); (3)
collection and infiltration; (4) collection and reuse; and (5) cityshed (i.e., watershed) restoration.
(“No action” is also a general response action that could be considered, but none of the technologies
were categorized as “no action”). The appropriateness of the technology for the site was evaluated
by three primary criteria: effectiveness, technical implementability, and retrofit cost. A technical
memo and spreadsheet was prepared by the District and is shown in Appendix H.
2.9.3 Process for Investigating Demolitions
A list of the buildings contracted to be demolished with MSD funds was first obtained from LRA.
MSD staff then developed a GIS map showing the entire city block, including the LRA-owned
parcels and the parcels with demolitions being funded by MSD (Figure 2-4). During the field visit,
staff looked at all the lots owned by LRA and
determined if one of the “Universe of
Technologies” could be constructed on the
property.
Since MSD paid for the demolitions on some
lots, city blocks containing those lots were
investigated first. If the block did not appear
to be a good candidate for a GI facility and
was in the Pilot Focus Area, then the lot was
marked for a development agreement with
reserve area. The reserve area was determined
by calculating the water quality volume for a
future bioretention cell based on the proposed
land use. If the block was outside the Pilot
Focus Area, then the lot was marked to be swapped for vacant LRA properties where MSD could
construct GI facilities.
2.9.4 Review Process for Viable Sites
During the field visit, MSD staff visited city blocks with and without MSD funded demolitions.
They looked for parcels owned by LRA where GI facilities from the “Universe of Technologies”
could be used. Once a desirable parcel was found, staff prepared a project folder with an exhibit
illustrating the project scope, field notes, hydraulic calculations, and a conceptual cost estimate. The
project folder was then sent to the project manager for review and approval. After in-house
approval, MSD staff then met with LRA to discuss the project and to verify that the City of St. Louis
did not have other plans for the parcel. The projects were then added to the project database.
Potential sites were investigated to see if there were any streets, alleys, or properties with impervious
area draining to the MSD funded demolitions or other LRA-owned properties. Factors such as the
slope of the site, elevation difference between the site and the street, current development in the area,
parking lots that drained to the site, and nearby location of churches and schools were considered.
After a site was considered viable in the field, the “Universe of Technologies” was used to determine
the most applicable GI for the location. The GI was designed based on the drainage area and the
higher of the planned and current impervious area for the water quality volume storm. The design of
the GI also considered how the water was getting into the facility and whether an overflow was
Figure 2-4 GIS Exhibit for Investigating Demolitions
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needed. After sizing the GI facility, the downstream system was evaluated to determine if detention
would be required and if there was enough room for detention.
2.9.5 Development of Cost Estimates
As with all MSD conceptual studies, a design and construction cost estimate was developed at a
conceptual level for each proposed GI facility. The “Universe of Technologies” was used to obtain
the associated retrofit cost per unit of provided stormwater storage volume. A spreadsheet was used
in the design of the bioretention cell facilities to calculate the water quality volume and determine
the size of the facility.
A unit cost of $20/cubic feet of storage for bioretention cells was obtained from the GI “universe.”
MSD considered whether the unit price was too high compared to other GI projects constructed in
the District and based on that analysis, recommended a reevaluation of the unit price. Using a
proposed city block scale project as an example, a detailed cost estimate was created using the
District’s pay item unit costs where available and the contractor furnished estimates for pay items
without defined unit costs. This exercise resulted in a unit cost of $17.50/cubic feet stored and was
used instead of $20/cubic feet stored for pricing bioretention cells, the most common type of GI used
in the Pilot.
For other types of GI facilities, the “universe” unit costs were assumed. One exception was a
calculated unit cost of $7/cubic feet for detention basins. It was later decided to itemize the
individual pay items in the basin construction which gave a lower and more accurate cost estimate.
2.9.6 Development of Conceptual Project Database
During the first part of the site selection process, Excel worksheets were used to keep track of the
city blocks visited, demolition locations, and potential projects. It quickly became apparent that a
database would be required to maintain the information in a central location and to make tracking
and record keeping readily available. After discussions by team members, it was decided that an
Oracle database would be the most appropriate for this program. An Oracle database provided the
power needed to generate the required tables, forms, and reports along with the ability to directly
communicate instantaneously with GIS. This allowed for ease of tracking the eventual projects on
the MSD mapping system. The database was designed so that when a project went to design it could
be linked to MSD’s Oracle E-Business Suite where projects are tracked from beginning to end. The
database was designed with a web application for easy input of data and higher control settings for
the data. This application tracked personnel who entered the information along with the date and
time.
2.9.7 Project Priority Matrix
The viable projects obtained from the site selection process were put into a project matrix and
classified by the following categories:
type (site or neighborhood scale)
location factors (watershed, CSO #, ward #, in ROW or on lot, etc.)
drainage from (street, yard, rooftop, etc.)
impervious area reduction (pavement abandonment, porous pavement, etc.)
collection/filter/discharge (planter box, amended soil, bioretention, extended detention, etc.)
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infiltration (rain gardens, berms, etc.)
reuse (rain barrel, cistern, etc.)
restoration (prairie, forest, etc.)
inlet method (curb bump-out, gutter sump, warped pavement, curb inlet, etc.)
pre-treatment (basin, forebay, etc.)
overflow (structure, bypass, or spillway)
flood detention (100-year, stacked, separate, none, etc.)
The matrix was not set up as an objective ranking system but rather a way for the selection team to
look at a variety of factors at the same time. If a much larger number of viable sites had been
identified, a more objective ranking method would have been warranted. As it was, the selection
team simply needed a method to determine which, if any, would be dropped, and a method to assign
priority to determine which would move forward as funding allowed. The projects were ranked
according to the classifications with priority given to those with unique characteristics.
Due to the small number of Site-scale projects, all projects identified were determined to move
forward. For Neighborhood-scale projects, 13 sites were identified as viable. They were each
evaluated according to the constructability, cost, and uniqueness of the project. The sites were then
issued a ranking number. Based on conceptual costs, 10 sites were planned to be constructed during
the Pilot and 3 sites were considered contingency projects (i.e., projects that might by constructed if
another project did not move forward or was dropped based on newly discovered information or
factors). The project rationale (why it’s different) was also stated in the matrix.
A copy of the Project Priority Matrix can be found in Appendix I.
2.9.8 Summary of Sites Selected
Two types of projects were selected for further design and implementation, Site-scale projects and
Neighborhood-scale projects:
Site-scale Projects – Site-scale projects selected to move forward included 13 planter boxes with
Habitat for Humanity in the JeffVanderLou (JVL) neighborhood, 2 rain gardens with a property
owner on Monroe Street who purchased two LRA properties adjacent to their home after the
demolitions funded by MSD had been completed, and 1 rain garden for a home being rehabilitated
through the Community Development Administration.
Neighborhood-scale Projects – There were a total of 10 Neighborhood-scale projects selected to
move forward in design and 3 were selected as contingency projects. Of the 13, all but one were
bioretention projects of a variety of sizes, some with detention, some without, and with a variety of
forebay types and configurations. A pervious alley project was also identified, but it was not
constructed because MSD could not reach agreement with the City of St. Louis regarding
maintenance of the alley. Following is a summary of the Neighborhood-scale sites and a brief
description of what made each unique. The project name includes the street on which the project is
located and the city block number.
Selected Projects – Following is a table of all of the Site-scale and Neighborhood-scale projects
selected to move forward into design:
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Table 2-5 Selected Projects
Project Type Rank Rationale Constructed?
Habitat for
Humanity 13
Planter Boxes in
JeffVanderLou
Site‐scale Site‐scale bioretention
applicable to
redevelopment
Constructed during GI
Pilot Program
Monroe St. 2
Site‐scale Rain
Gardens in Old
North
Site‐scale Site‐scale retrofit
adjacent to habitable
home
Constructed during GI
Pilot Program
Harlan Av. 1 Site‐
scale Rain
Garden in Baden
Site‐scale Site‐scale retrofit
adjacent to habitable
home
Constructed during GI
Pilot Program
Clinton St.
Pervious Alley in
Old North
Neighborhood‐
scale
1 Only pervious alley
being used as
Neighborhood‐scale,
high redevelopment
potential
Not constructed. Could
not come to agreement
with the City of St.
Louis regarding
maintenance of the
alley
Clinton St. Rain
Garden in Old
North
Neighborhood‐
scale
2 High redevelopment
potential, mid‐sized
bioretention with
detention, bumpout,
potential "adopter"
organization
Constructed during GI
Pilot Program
N. Vandeventer
Ave. Rain Garden
in JeffVanderLou
Neighborhood‐
scale
3 Large bioretention,
potential downspout
disconnection pilot due
to large number of
homes in drainage area
Constructed during GI
Pilot Program
N. Sarah St. Rain
Garden in The
Ville
Neighborhood‐
scale
4 Only Neighborhood‐
scale in Western Mill, 3
demo sites, parking lot
drainage, pretreatment
basin
Constructed during GI
Pilot Program
Geraldine Ave.
Rain Garden in
Mark Twain
Neighborhood‐
scale
5 Only Harlem & Ward 1,
church next door, small
Constructed during GI
Pilot Program
Beacon Ave. Rain
Garden in
Walnut Park East
Neighborhood‐
scale
6 Only Baden, separate
100‐yr detention from
bioretention
Constructed during GI
Pilot Program
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Project Type Rank Rationale Constructed?
Warne Ave. Rain
Garden in
O’Fallon
Neighborhood‐
scale
7 Only Neighborhood‐
scale bioretention
totally contained in
ROW ‐ establish
maintenance
relationships
Constructed during GI
Pilot Program
Linton Ave. Rain
Garden in
Fairground
Neighborhood‐
scale
8 Only Neighborhood‐
scale in Prairie, 3 demo
sites, pretreatment
basin
Constructed as an Early
Action project due to
limited funding during
GI Pilot
Blair Ave. Rain
Garden in Hyde
Park
Neighborhood‐
scale
9 Only Neighborhood‐
scale in Ferry, 2 demo
sites, medium
bioretention
Constructed as an Early
Action project due to
limited funding during
GI Pilot
19th St. Rain
Garden in Hyde
Park
Neighborhood‐
scale
10 Small bioretention,
different overflow
Constructed as an Early
Action project due to
limited funding during
GI Pilot
Prairie Ave. Rain
Garden in
Fairground
Neighborhood‐
scale
C1 1 demo, many projects
in ward 3
Constructed as an Early
Action project
Lee Ave. Rain
Garden in
O'Fallon
Neighborhood‐
scale
C2 1 demo, needs
infrastructure upgrade
Constructed as an Early
Action project
N. Spring Rain
Garden in
JeffVanderLou
Neighborhood‐
scale
C3 1 demo, have large
similar project in Rocky,
might have to replace
pipe
Constructed as an Early
Action project
Table 2-5 Selected Projects
2.9.9 Challenges and Lessons Learned
LRA-owned Demolition Parcels
The parcels with structures to be demolished were selected by LRA and the demolition list had
already been prioritized. Therefore, MSD had to work with parcels scattered throughout the City of
St. Louis. From a stormwater collection perspective, parcels that are clustered together (or
contiguous) and/or located at low points would have been ideal. However, as is the case with all
partnerships, MSD had to work within the constraints and priorities of our partner, LRA, to make the
best use of various types of GI technologies for both the Neighborhood-scale and Site-scale projects.
Adjacent Parcels
There are only a few locations where the parcels with demolitions parcels are contiguous. Site
investigation revealed that several parcels are located between dilapidated houses. Most likely, these
buildings will be torn down in the near future. Due to lack of working room on these narrow
parcels, there is a strong probability that a GI facility would be significantly disturbed during the
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demolition of the neighboring parcels. Therefore, the GI that could be built will be subject to
impacts from future activities in the block. These parcels were evaluated during the site selection
process and the lack of working room was taken into account during the prioritization of parcels.
Existing Structure Conditions
During the site selection process for the Site-scale projects, an alternative was investigated to
disconnect and re-direct neighboring downspouts to a GI facility on the neighboring vacant LRA-
owned property. However, in many instances, the roof gutters and downspouts on the neighboring
house were missing. These gutters and downspouts were made of copper and had been stolen.
Replacing gutters on a private residence and re-directing the flow across a property was determined
to be problematic. Therefore, existing structure conditions provided limited ability to direct
downspouts to GI and this was taken into account during the site selection process.
Topography
The vast majority of single-family parcels
in the City of St. Louis are approximately
0.1 acre lots – typically 30’ to 35’ wide
and about 125’ from street to alley. The
footprint of the house is perched, i.e., the
first floor level sits at least 2 to 3 feet
above street level. Front yards typically
drain to the street, rear yards typically
drain to the alley, the house roof area is
collected in the private lateral, and the
detached garage downspouts daylight
directly to the alley. Given this scenario
for every parcel, collecting impervious
runoff from the public right of way or
from neighboring properties is nearly
impossible. In fact, during the screening
process to evaluate the most appropriate GI facility size and type, 93% of the LRA-owned parcels
with demolitions were determined not desirable for Neighborhood-scale projects. Therefore,
considering all eligible real estate in the City of St. Louis, only a small number of parcels are
suitable for future Neighborhood-scale bioretention. These parcels were evaluated during the site
selection process and the lot topography was taken into account during the prioritization of parcels.
2.10 Evaluation of Site Selection Methodology
The site selection methodology used for the Pilot was tailored to fit the parameters set up in
Appendix Q of the LTCP. The method started by gathering data through GIS and evaluating
individual city blocks for further investigation. However, as demolition locations were determined
by LRA, the investigation focused more on opportunities at or near the demolition locations.
It is recommended that future site selection of Neighborhood-scale projects go back to the initial
Phase 1 analysis and further refine it in order to narrow down potential city blocks for facilities. For
example, the CSO region in which the block is located may play a higher role in ranking potential
blocks. MSD could start the investigation of blocks in a CSO region with a higher rank in terms of
Figure 2-5 Typical Lot After Demolition
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CSO volume reduction in response to reduced imperviousness. LRA property is constantly
changing, either through sales or additional acquisition, so some of the original Phase 1 analysis will
need to be updated.
2.11 Facility Design and Construction
For a map of all facilities constructed during the Pilot, see Appendix DD.
2.11.1 Design Approach
Through the development and implementation of the SWMP and as further discussed in Section 2,
MSD has required post-construction stormwater management (i.e., stormwater BMPs) on new
development and redevelopment projects in the separate sewer area since 2006. Most of the
allowable BMPs are the GI practices used in the Pilot. As such, there are already rules and
regulations governing the design of GI facilities and there are mechanisms in place to enforce their
operation and maintenance with regard to private developments. Internally, however, MSD had
done very limited design of GI facilities and did not itself own any stormwater GI facilities. Those
processes had to be developed during the Pilot.
The current design standard used for the stormwater BMPs in the separate sewer area is intended to
treat the “water quality storm,” or the 90% non-exceedance 24 hour storm depth of 1.14 inches. In
other words, 90% of rainfall events in a given year are 1.14 inches or below. This design standard
targets the removal of suspended sediments and is essential to water quality within the separate
storm sewer systems. The target volume treated is the “water quality volume” (WQv), as defined by
the MSD Rules and Regulations and Engineering Design Requirements for Sanitary Sewer and
Stormwater Drainage Facilities, February 2006 (MSD Rules and Regulations) (MSD, 2006),
calculated as:
WQv (acre-feet) = [(P)(Rv)(A)]/12
P = rainfall depth in inches and is equal to 1.14 inches
Rv = 0.05 + 0.009 (I) where I is percent impervious cover (in percent)
A = drainage area to the facility in acres
Because the Pilot is in the Combined sewer area and for the purpose of CSO volume reduction, the
design of GI for the water quality storm is not an essential priority as low flows will be treated at a
wastewater treatment plant. However, the methodology developed for treating the water quality
storm has been well established and has become well known by the engineering community. In the
Combined sewer area, this standard is occasionally used when there are capacity issues in the system
downstream of a new development of redevelopment project, especially when site constraints
preclude the use of larger flood detention facilities. In addition, there has also been research to show
the water quality design standard and typical facilities, especially bioretention facilities, do a good
job of mimicking natural runoff for the soil and bedrock conditions found in the Program Area
(Hoskins and Peterein, 2013).
Therefore, an argument could be made that following this standard would effectively negate the
influence of the impervious surfaces in the drainage area when diverted to GI practices. For these
reasons, the 1.14 inch water quality storm was adopted for the Pilot design standard. The design
methods can be found in the MSD Rules and Regulations.
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Using the same design standard as what has been required for stormwater BMPs in the separate
sewer area also allows designers to make use of the design tools and details that have been
developed for the MS4 program. This “BMP Toolbox” is available on MSD’s website, and
includes: information about the development review process; information on allowable technologies,
design calculation and report preparation tools; maintenance agreement information including a
checklist and example; construction information such as shop drawing review, deposits and MSD
permits and inspection; and maintenance information including responsibilities, checklist, and
requirements for annual reporting.
2.11.2 Site-scale Facilities
As described previously, Site-scale facilities are designed to capture runoff from a single parcel,
typically from the roof or other impervious area on the property. Since these facilities are on
individual properties, maintenance is the responsibility of the property owner.
MSD paid for three types of Site-scale facilities during the Pilot. Planter boxes and rain gardens
were built where there was a habitable structure either existing or being constructed as a
redevelopment project. A limited number of amended soil sites were constructed where there had
been a demolition without redevelopment of the lot.
2.11.2.1 Rain Gardens and Planter Boxes
The following 16 Site-scale rain gardens and planter boxes were designed and constructed during the
Pilot:
Project Name GI Practice Type Facility Address MSD
Project #
Habitat for Humanity Planter Boxes in
JeffVanderLou
Planter Box 2956 Thomas St. P‐28660‐01
Planter Box 2954 Thomas St.
Planter Box 2946 Thomas St.
Planter Box 2944 Thomas St.
Planter Box 2942 Thomas St.
Planter Box 2940 Thomas St.
Planter Box 2945 Thomas St.
Planter Box 2951 Thomas St.
Planter Box 2953 Thomas St.
Planter Box 2957 Thomas St.
Planter Box 2944 Sheridan Ave.
Planter Box 2942 Sheridan Ave.
Planter Box 1341 N. Garrison
Ave.
Monroe St. Lot‐scale Rain Gardens in
Old North
Rain Garden 1451 Monroe St. P‐29210‐00
Rain Garden 1453 Monroe St.
Harlan Av. Lot‐scale Rain Garden in
Baden
Rain Garden 835 Harlan Ave. P‐29340‐00
Table 2-6 Site-scale Rain Gardens and Planter Boxes
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As private facilities, these projects were reviewed by MSD’s Engineering Department/Development
Review group and the District’s Construction group provided inspection for approval of payment.
The Monroe Street Rain Gardens were designed by MSD staff but the others were designed by the
developer. The construction was bid by the property owner or developer and reimbursed by MSD.
The design approach for the rain gardens and the planter boxes was the same as that for the
Neighborhood-scale bioretention facilities. These smaller sites are intended to operate as micro-
bioretention facilities.
Following is a brief description of the projects listed above. For additional detail, see Appendix J.
Habitat for Humanity Planter Boxes in JeffVanderLou
Habitat for Humanity St. Louis is a not-for-profit ecumenical housing organization that helps
provide housing for families. Since the early 1990s, Habitat for Humanity has constructed
approximately 250 houses in the CSO GI Program Area and LRA has donated numerous parcels to
Habitat for Humanity for the construction of new homes. The redevelopment project in the JVL
neighborhood was a second phase for that particular development. The first phase involved
installation of an individual rain garden for each house. The timing of the second phase worked well
for inclusion in the Pilot. The additional houses were each designed to include a planter box
attached to the back of the home, with the 1,273 square feet of roof area going into the planter box.
See Figure 2-6 for a map showing the development and houses with rain gardens and planter boxes.
This development gave MSD a unique opportunity for monitoring during the Pilot since almost
every house in a city block had an individual GI facility. The monitoring protocol is discussed in
Section 2.15.
Figure 2-6 JeffVanderLou Habitat For Humanity Development
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Each planter box included an overflow and underdrain system that connected to the combined sewer
system, thereby retaining some volume within the pore spaces of the soil media or taken up by plants
through evapo-transpiration, and some was detained and slowly drained into the sewer system. See
Figures 2-7 and 2-8 for a cross section view of a planter box, and a photo of one of the constructed
boxes. MSD reimbursed Habitat for Humanity $3000 for each planter box (although the actual cost
was reportedly higher, even with discounts and some volunteer time) and all of the planter boxes
were constructed in the fall of 2011.
Figure 2-7 Planter Box Section
Figure 2-8 Typical Planter Box Installation in the JeffVanderLou Neighborhood
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Monroe St. Lot-scale Rain Gardens in Old North
This project involved installation of two rain gardens at 1451 and 1455 Monroe Street in the Old
North St. Louis neighborhood in the City of St. Louis. 1451 and 1455 Monroe Street previously
consisted of two condemned residential buildings. As part of the Pilot, the LRA demolished the
buildings and MSD recorded a Development Agreement with Reserve Area for a future GI facility to
be located when the parcels are redeveloped, as explained in Section 2.8. The homeowner at 1453
Monroe Street purchased these two lots from the LRA with the intent to use them as side yards and
green space. Installation of rain gardens to divert the impervious surfaces of the existing home and
carriage house on 1453 Monroe was discussed and agreed to. An assumed future impervious surface
of 50% of the lots was used as a basis for sizing the gardens in order to accommodate for the future
sale and redevelopment of the lots. As a result, the gardens are considerably oversized for the
current condition.
MSD assisted with design of the rain gardens and the property owner hired a contractor to install
them. The project was submitted through the Development Review group for compliance with
MSD’s Rules and Regulations and to ensure that the contractor was entered into MSD’s permitting
and inspection system. MSD reimbursed the property owner $7,100 for the cost of constructing the
two rain gardens that were completed in the spring of 2012. See Figure 2-9 for a photo of the rain
garden at 1451 Monroe.
Figure 2-9 Rain Garden at 1451 Monroe St.
As mentioned above, the rain gardens are designed as micro-bioretention facilities. Since the
existing site soils at this site are of low permeability, the rain gardens include an “underdrain”
constructed of pea gravel wrapped in geotextile to act as a seepage path into the overflow channel
and to prevent excessive ponding.
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Harlan Av. Lot-scale Rain Garden in Baden
The City of St. Louis’ Community Development Administration (CDA) partnered with the
Riverview West Florissant Development Corporation, a 501(c) 3 agency that undertakes community
development activities, to rehabilitate the house at 835 Harlan Avenue in the Baden neighborhood.
MSD discussed with CDA potential rehab projects that could be good demonstrations of Site-scaled
GI facilities. This house was recommended for the Pilot and MSD staff worked with Riverview
West Florissant Development Corporation’s architect in order to incorporate a rain garden into the
design plans of this reconstructed house. The design plans were reviewed and approved by MSD’s
Development Review group. Approximately 1,700 square feet of the property’s impervious area
(driveway, sidewalk and portions of the roof) and some pervious areas are directed to the rain
garden.
Later in the Pilot, as the system models were reviewed in preparation for estimating the impact the
CSO GI Program will have on CSO volume discharges, the CSO GI Program Area was revised.
With this revision, the rain garden at 835 Harlan is slightly outside of the CSO GI Program Area.
For that reason, it is not included in the estimated CSO volume discharge reduction. It did, however,
provide valuable information into the logistics of working with the CDA and with home
rehabilitation projects.
Amended Soil
In order to determine the effectiveness of amended soil techniques, 13 parcels were identified for
soil amendments during the site selection process. All of the parcels are in rows of two or more,
resulting in 5 amended soil sites. These sites were combined to allow for two bid packages named
“Amended Soil Package #1” and “Amended Soil Package #2.”
Following is a list of the 13 parcels:
Project Name Site GI Practice Type Facility Address MSD
Project #
Amended Soil
Package #1
Site 1 Front – compost amendment
Rear – aerate and top dress 4228 Warne Av.
11048
Front – compost amendment
Rear – aerate and top dress 4232 Warne Av.
Front – compost amendment
Rear – aerate and top dress 4234 Warne Av.
Front – compost amendment
Rear – aerate and top dress 4238 Warne Av.
Front – compost amendment
Rear – aerate and top dress 4240 Warne Av.
Site 2 Aerate and top dress 4133 Lea Pl.
Compost Amendment 4135 Lea Pl.
Amended Soil
Package #2
Site 3 Front – compost amendment
Rear – aerate and top dress 3832 Labadie Av.
11048
Front – compost amendment
Rear – aerate and top dress 3834 Labadie Av.
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Site 4 Compost Amendment 3139 N. Sarah St.
Compost Amendment 3143 N. Sarah St.
Site 5 Compost Amendment 4021 Glasgow Av.
Compost Amendment 4023 Glasgow Av.
Table 2-7 Amended Soil Sites
The amended soil projects were not designed for a particular design storm or volume. The goal of
the projects was to gain information regarding different amended soil techniques. Therefore, two
techniques were used. One technique is to clear the surface, core aerate the existing soil, top dress
with fertilizers according to soils analysis, and then install sod. The other technique is to clear the
surface, rototill to a depth of 6 to 8 inches, add 2 inches of compost and rototill again, and then
install sod.
Existing soil samples were taken from each of the sites and sent to a University of Missouri
Extension soil testing lab for analysis. Each sample was analyzed for pH, Phosphorus, Potassium,
Calcium, Magnesium, Organic Matter, and acidity. The report included recommended application
rates for Nitrogen, Phosphorus, Potash and Lime, as applicable for growing common lawn grasses.
For all the compost amended sites, the specified compost would cover any necessary fertilization, so
only the “aerate and top dress” sites received additional fertilizers.
The two packages of amended soil sites were constructed during the Pilot in the fall of 2011 and
spring of 2012. Each was designed by MSD. Construction was bid through MSD’s Small
Contractor Program, which allows for simplified contractor requirements and bid process for
projects with construction less than $25,000.
2.11.3 Neighborhood-scale Facilities
As described previously, Neighborhood-scale facilities are GI facilities designed to capture runoff
from multiple lots as well as adjacent roadways and alleys. MSD acquired the parcels from LRA
and maintains these facilities. The facilities are designed for a future, redeveloped condition in the
drainage or tributary area. See Appendix J and Appendix K for more details regarding the design
and construction of the Neighborhood-scale facilities.
Project Name GI Practice
Type
Facility Address MSD
Project
#
Planted
Clinton St. Rain Garden in Old
North
Bioretention
w/ Detention
1323 Clinton Street 11157 Fall
2012
N. Sarah St. Rain Garden in
The Ville
Bioretention 1801 North Sarah 11778 Spring
2013
N. Vandeventer Ave. Rain
Garden in JeffVanderLou
Bioretention 2812 North
Vandeventer
11778 Spring
2013
Geraldine Ave. Rain Garden in
Mark Twain
Bioretention 5099 Geraldine
Avenue
11802 Spring
2013
Beacon Ave. Rain Garden in
Walnut Park East
Bioretention
w/ Detention
5479 Beacon Avenue 11802 Spring
2013
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Warne Ave. Rain Garden in
O’Fallon
Bioretention 4241 Warne Avenue 11804 Fall
2013
Table 2-8 Neighborhood-scale Facility Constructed During the Pilot
Table 2-8 lists the 6 facilities designed and constructed during the Pilot. Each includes a
bioretention cell with an underdrain. The underdrain outlet is elevated, creating an area of internal
water storage (IWS) within the rock layers below the soil. Two of the facilities include additional
storage to act as detention to address downstream capacity concerns. See Figure 2-10 for a
schematic cross section of a typical bioretention cell with IWS.
Figure 2-10 Schematic of Typical Bioretention Cell
Each of the bioretention facilities also includes a forebay where flow enters the facility. The forebay
acts as pre-treatment by catching trash and debris as well as coarse sediment in an area that is easy to
access and clean, thereby easing maintenance and prolonging the life of the bioretention filter.
Figure 2-11 shows the forebay at the N. Sarah Street Rain Garden in The Ville neighborhood.
The Neighborhood-scale bioretention projects were designed by MSD’s internal design staff. As
explained earlier, these projects were unique in that MSD rarely designs and constructs GI facilities.
However, thanks to the experience from private development with these type of facilities, design
tools, details, and specifications could be adapted or developed in order to create the construction
plans and specifications needed. Process documents were also created to supplement the “normal”
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design procedures for unique aspects of
GI design and requirements of the pilot.
Whenever possible, the procedures
mimicked processes already in place.
The Neighborhood-scale facilities are
intended to manage stormwater from a
future, redeveloped condition. The
bioretention cells are designed for the
WQv described above, using a predicted
redeveloped impervious area of 50% for
residential areas and 75% impervious
for commercial areas. If the current
imperviousness of a parcel was higher
than the predicted future value, the
higher value was used.
The downstream system was evaluated using hydraulic models and customer complaint data to
determine if detention is needed to address capacity issues. If needed, a detention volume was
determined such that the peak flow for the 20-year, 24-hour storm is restricted to an all grass
condition. If space allowed, the 100-yr, 24-hour storm was detained.
Figure 2-12 Example of a Neighborhood-Scale Pilot Project Grading Plan
To assist MSD design staff with unique aspects of the program, MSD contracted a general services
agreement with a local engineering firm. Through the contract, MSD was able to task out
environmental site assessments, geotechnical exploration, and landscape design services.
Figure 2-11 Forebay at the N. Sarah Street Rain Garden in The Ville
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Figure 2-13 Excavation for a Neighborhood-scale Bioretention Cell
Because MSD would own and operate these facilities, each site was evaluated using Phase I
Environmental Site Assessment procedures in order to determine potential environmental threats.
Geotechnical exploration was conducted at each site to determine the extents of former building
footprints and infiltration rates of the in situ soils. Historic maps used to locate former building
locations and open trenching, as opposed to borings, were chosen where feasible to provide better
insight of the site-specific subsurface conditions.
Inclusion of a qualified landscape designer was integral to the goal of making the Neighborhood-
scale projects an enjoyable amenity for the residents living around them and for promoting GI in the
urban setting.
Construction of the Neighborhood-scale bioretention projects was bid through MSD’s normal capital
project process, using pre-qualified contractors and a formal advertisement and bid process. Each
contract went before MSD’s Board of Trustee for approval. All projects included a pre-bid meeting
attended by MSD, the landscape architect, and potential contractors. Following is a brief description
of each Neighborhood-scale facility. See
Appendix J for more details.
2.11.3.1 Clinton Street Rain Garden in Old North
The Clinton Street Rain Garden is located at the
northeastern corner of 14th Street and Clinton
Avenue in the Old North St. Louis neighborhood
of the City of St. Louis. It treats a drainage area
of approximately 1.7 acres, including several new
homes constructed by Habitat for Humanity, as
well as runoff from the alley and street. The
facility is a 2,140 square foot bioretention filter
with IWS. This facility also includes added Figure 2-14 Clinton Street Rain Garden in Old North
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storage for detention that is “stacked” above the bioretention. This is accomplished by setting the
low flow opening on the control structure 12 inches above the basin surface. Care is taken to not
allow excessive ponding which could compact the bioretention soil or kill the plants.
2.11.3.2 N. Sarah St. Rain Garden in The Ville
The North Sarah Street Rain Garden is
located near the northwestern corner of
North Sarah Street and North Cote
Brilliante Avenue in The Ville
neighborhood of the City of St. Louis. It
treats a drainage area of approximately
1.4 acres. The majority of the lots are
occupied with buildings. The block
slopes gradually toward the alley where
the proposed facility will intercept the
stormwater runoff. The facility is a 1,236
square foot bioretention filter with IWS
and a flagstone forebay.
2.11.3.3 N. Vandeventer Ave. Rain Garden
in JeffVanderLou
The North Vandeventer Avenue Rain Garden
is located near the northeastern corner of
Maffitt Avenue and North Vandeventer
Avenue in the JVL neighborhood of the City
of St. Louis. The facility treats a drainage
area of approximately 3.5 acres. The
majority of the lots are occupied with
residential buildings or multi-family units.
The block slopes gradually toward the alley
where the proposed facility will intercept the runoff. The facility is a 2,570 square foot bioretention
filter with IWS and a turfstone forebay. The N. Vandeventer facility was also designed with a
monitoring manhole to facilitate flow monitoring as described in Section 2.15.
2.11.3.4 Geraldine Ave. Rain Garden in Mark
Twain
The Geraldine Avenue Rain Garden is located at
the northwest corner of Geraldine Avenue and
Thekla Avenue in the Mark Twain neighborhood
of the City of St. Louis. The facility treats a
drainage area of approximately 0.4 acres of
currently vacant lots. The facility includes a 335
square foot bioretention filter with IWS. The
forebay for the facility was created in a curb
“bump-out” which can also provide traffic
calming. The Geraldine Avenue facility was also
Figure 2-15 N. Sarah St. Rain Garden in The Ville
Figure 2-16 N. Vandeventer Ave. Rain Garden in JeffVanderLou
Figure 2-17 Geraldine Ave. Rain Garden in Mark Twain
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designed with a monitoring manhole to facilitate flow monitoring.
2.11.3.5 Beacon Ave. Rain Garden in Walnut Park East
The Beacon Avenue Rain Garden is located at the
northwest corner of Beacon Avenue and Harney
Avenue in the Walnut Park East neighborhood of
the City of St. Louis. The facility treats a drainage
area of approximately 1.8 acres including multiple
residential homes and some vacant lots.
The facility includes a 1,248 square foot
bioretention filter with a separate cell to act as
detention. The bioretention filter includes IWS and
a forebay.
Flow enters the facility through the forebay, spills over a cobble spillway to the bioretention cell, and
then flows to the detention cell.
2.11.3.6 Warne Ave. Rain Garden in O’Fallon
The Warne Avenue Rain Garden is located near
the northeastern corner of Green Lea Place and
Warne Avenue in the O’Fallon neighborhood of
the City of St. Louis. This facility is the only
project located entirely in the street right-of-way.
It treats a drainage area of approximately 0.7
acres, which is comprised of a combination of
vacant lots and residential buildings. A portion of
the block slopes gradually toward Green Lea Place
where the proposed facility will intercept the
runoff. The facility includes a 800 square foot
bioretention filter with IWS and a flagstone forebay.
2.11.4 Design and Construction Lessons Learned
The Neighborhood-scale Pilot projects provided MSD an opportunity to work through the technical
and logistical process for designing, building, and maintaining GI facilities. The facilities were
successfully designed and installed, and maintenance so far has been routine, other than a few
isolated instances of dumping or vandalism. Following are a few of the lessons that will help to
inform the process of implementing additional Neighborhood-scale facilities during the full-
implementation of the CSO GI Program.
Estimate of Cost
Table 2-9 shows a comparison of the conceptual cost when the design was started, and the final
constructed cost. As can be seen in the table, the final costs varied from 3% to 361% higher than the
conceptual cost. The highest change was the smallest facility on Geraldine Avenue. The original
plan for that facility did not include the monitoring manhole for monitoring, as well as a water
source which was added to all of the facilities, other than the one on Warne. If the Geraldine Rain
Garden is taken out, the average is 20% increase in final cost over conceptual cost.
Figure 2-18 Beacon Ave. Rain Garden in Walnut Park East
Figure 2-19 Warne Ave. Rain Garden in O'Fallon
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Part of this differential in cost was due to providing a water source at the facilities. Also, the original
cost estimating data was associated with construction of stormwater BMPs constructed as part of an
overall development typically in green fields under an MS4 environment. Conversely, MSD
constructed the Pilot facilities individually in a retrofit situation, which is inherently more costly.
Also, the size of the drainage area and basin for the city blocks selected was generally smaller than
the size of new developments, so economies of scale were not realized.
Project Name Conceptual
Cost
Final
Construction
Cost
%
Higher
Design
Capacity
(cu. ft.)
Cost per
cu. ft.
Clinton St. Rain Garden
in Old North $ 141,000 $ 184,873.46 31% 4,155 $ 44.49
N. Sarah St. Rain Garden
in The Ville $ 120,000 $ 123,782.50 3% 5,482 $ 22.58
N. Vandeventer Ave.
Rain Garden in
JeffVanderLou $ 96,000 $ 114,005.50 19% 3,090 $ 36.89
Geraldine Ave. Rain
Garden in Mark Twain $ 20,000 $ 92,214.86 361% 1,205 $ 76.53
Beacon Ave. Rain Garden
in Walnut Park East $ 101,000 $ 128,355.12 27% 3,461 $ 37.09
Warne Ave. Rain Garden
in O’Fallon $ 46,000 $ 65,287.00 42% 1,427 $ 45.75
Table 2-9 Neighboorhood-scale Facility Construction Costs
Pay Items/Bidding
Since MSD had little experience bidding bioretention cells prior to the Pilot, there is no history of
bid items and prices. It was considered inefficient to add dozens of pay items, many of which could
be very small quantities and difficult to measure in the field. Therefore, to deal with this new issue,
it was decided each site would be paid for by a single pay item, e.g. “Site 1”. However, a Schedule
of Values (SOV) was requested from each bidder to provide a more traditional breakdown of items,
quantities, and cost. The SOV also provided information needed to address any potential change
orders during construction.
Forebay Transition
The design of the forebay transition area in a bioretention basin can be quite puzzling. On one hand,
the inflow velocity must be reduced enough for the sediment to drop out but on the other hand, the
forebay needs to drain in a reasonable amount of time. Any system that drains slowly through
narrow openings is also prone to clogging. A technique that seems to be working well is that of a
“boulder berm” where water is able to seep between the spaces between the boulders. The natural
boulders also complement the plantings and can be repeated in other rock features. Early projects
experienced some clogging by leaves and mulch if the rocks were too close together. Therefore, the
specifications have been changed to include a minimum spacing of one inch between the boulders in
addition to the maximum spacing of three inches. Another caution is to be sure the elevation drops
after the forebay in order to ensure flow through the berm.
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Availability of Materials
Due to MSD’s stormwater regulations requiring the design and installation of various stormwater
BMPs, several suppliers in the region had begun providing needed materials such as bioretention
cells. MSD was able to capitalize on this familiarity and specify materials such as aggregate and
bioretention soil mix in accordance with that locally available. The close proximity of several rivers
in the region provides rounded, durable river aggregate of particular suitability for use in
bioretention facilities.
Construction Inspection
MSD generally has inspectors present in the field during construction. Due to the unique nature of
the projects as compared to MSD’s typical capital and infrastructure repair projects, the inspectors
had varying knowledge of GI construction techniques. In-house training was provided for MSD
inspectors. Plant related submittals and field checks were conducted by a landscape architect, but all
other construction items were handled by the MSD inspector.
Buried Rubble
Excavation and grading of the facilities was complicated by the presence of buried rubble due to
previously demolished buildings. The typical standard for demolition by LRA’s contractors was
followed, which allows for the basement floors and walls to be broken up, and non-hazardous rubble
to be used to fill the basement. Only a shallow layer of “clean” fill is required at the top.
Demolitions that occurred at various points in the past had even less stringent criteria, so some
locations even had some intact building
foundations (Figure 2-20).
To accommodate for this in the design and
bidding of the projects, the geotechnical
investigation used open trench exploration, as
well as review of historic “fire marshall maps”
to estimate the extents of the building rubble,
which was included in the construction
specifications. Additionally, the construction
specifications required that building rubble
encountered during excavation for the
bioretention facilities be removed to a depth of
two (2) feet below the proposed bottom of the
bioretention facility. Geotextile fabric was
then used to “bridge” over remaining rubble to obtain smooth and workman-like grading surfaces.
The amounts of rubble excavated were extensive at each site.
A similar situation existed with the amended soil projects. Within the first 8 inches of soil, broken
pieces of bricks and concrete were common. All of this led to higher excavation costs and, hence
higher total project costs.
Vandalism
While aesthetically pleasing and appreciated by the immediate neighbors, several of the completed
project sites have been the victim of vandalism. The first instance was reported in June 2012 by
Figure 2-20 Intact Foundation at a Neighborhood-scale
Facility Site
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MSD staff during a routine inspection route of the amended soil sites. One thousand square feet of
newly placed sod had been stolen from the Glasgow Avenue site.
Based on monthly inspections by Operations staff for the first half of 2014, there were 5 documented
reports of damaged or stolen plants or sedges and a stolen cleanout cap. Other instances of vandalism
include (some reported by neighbors to the inspectors or maintenance contractors):
Children riding bicycles through the N. Vandeventer basin.
Several reports of the Meramec River cobble stones removed from the basins at N.
Vandeventer, Geraldine, and Beacon sites. The adjacent property owners reported several
broken house windows and/or parked car windows due to someone throwing these stones.
At the N. Sarah site, sod was installed on the afternoon of May 16, 2013. During the
inspection the following morning, half of it had been stolen.
Evidence of a vehicle that drove across one corner of the N. Sarah basin.
Several trees broken off at ground level at the N. Vandeventer site.
One sign post damaged at the Beacon Avenue site.
A plexiglass cover for the sign at the Clinton Avenue site was damaged shortly after
installation.
Over $1,200 worth of maintenance equipment (gas weed trimmers and backpack blowers)
were stolen from a maintenance contractor while they were working on the Beacon Avenue
site. A police report was filed by the contractor.
MSD will continue education and outreach efforts as one means of minimizing the vandalism. In
regards to the incident of stolen maintenance equipment, MSD’s Risk Management staff offered
several suggestions with regards to the safety of MSD staff and contractors, which will be
incorporated into our activities to minimize the risk of theft.
2.12 Post-construction Inspection and Maintenance
This section explains how MSD has developed mechanisms and procedures to ensure long-term
performance and maintenance of GI projects constructed as part to the Pilot. Also included is a
summary of inspection and maintenance activities conducted during the Pilot.
2.12.1 Site-scale Rain Gardens and Planter Box Facilities
Since all of the Site-scale facilities are privately owned, maintenance is the responsibility of the
property owner. MSD used the logistics followed for regulated BMPs in the Separate Sewer Area
under the MS4 Program to ensure long-term sustainment of these facilities. As part of MSD’s
development plan review process, the property owner is required to sign a Maintenance Agreement
that ensures private stormwater management facilities will be maintained by the current property
owner. Once executed by the property owner and MSD, the Maintenance Agreement is recorded
with the appropriate Recorder of Deeds office. An example of a recorded Maintenance Agreement
is provided in Appendix G. MSD also requires an Operation and Maintenance Plan be submitted
during the approval process, which must include a recommended maintenance schedule and specify
maintenance activities.
Enforcement of Maintenance Agreements is handled by MSD’s Division of Environmental
Compliance (DEC). Typically, DEC inspects BMPs every three years and commercial owners are
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required to submit an annual maintenance report. DEC has educational information and programs in
place to help BMP owners understand their responsibilities and typical maintenance.
The MS4 Program processes worked well for the Pilot projects with regard to ensuring the GI
facilities were reviewed, inspected, mapped, and entered into DEC’s inspection and enforcement
program. The only revision to the process for the Pilot was to increase the inspections by DEC to
annual inspections during the Pilot. This revision was necessary in order to identify and address
issues earlier, to better track and understand GI maintenance needs and the owners’ engagement, and
to more adequately inform the full-scale implementation of the CSO GI Program. After the Pilot,
inspections will revert to the typical three year interval. Based on knowledge gained from the
thousands of stormwater BMPs MSD has inspected as part of the MS4 Program and the privately-
owned Pilot projects, MSD will continue to gather information on the function of common and new
GI practices and use the inspections as an effective tool to provide information to owners on
maintenance. Sharing findings from the inspections with owners allows MSD to bring their
attention to needed maintenance which can aid in ensuring the effective long-term performance of
the GI practice.
Through the annual inspections of the Site-scale facilities and other education and outreach
explained in Section 2.13, MSD has found that maintaining vegetation is often tedious or confusing
for property owners. In some cases, property owners removed plantings or allowed overgrowth.
Other owners did maintain vegetation and took pride in making their GI facilities amenities to their
home. Long-term maintenance of vegetation can be costly and time consuming for individual
homeowners. Systems constructed during the Pilot continued to be operable, i.e. allow infiltration
and maintaining ponding area, even in the absence of routine vegetation maintenance. Consideration
for early property owner engagement and modifications to required plantings is important for future
planning for privately owned GI, especially those with more frequent routine maintenance
requirements.
2.12.2 Amended Soil
The amended soil Site-scale facilities are located on property owned by the LRA. Because of
uncertainty as to how the parcels would be developed in the future, a Development Agreement with
Future Reserve Area, as described in Section 2.8, was recorded for each parcel. This agreement
requires that a stormwater management control is constructed on the site if the site is redeveloped.
Since these parcels are still owned by LRA, they retain responsibility for maintenance, which is
limited to mowing the parcels as they do with all of their properties.
2.12.3 Neighborhood-scale Facilities
With the exception of a few detention basins, the Neighborhood-scale facilities are the first GI
facilities that MSD has owned and operated. Therefore, internal processes and procedures had to be
set up to both transition from construction contractor maintenance responsibilities to MSD’s
Operations Department, as well as for long-term inspection and maintenance.
Immediate post-construction maintenance was written into the projects’ technical specifications to be
the responsibility of the construction contractor for a 60-day period from the acceptance of plant
installation. The construction contractors are also bound by a one-year warrantee period to address
any issues, such as plant mortality, that would be attributable to materials or quality of installation.
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Beyond that, responsibility for maintenance is vested with MSD’s Operations Department. A
Stormwater Facility Management Report was created for each facility during the design phase. The
report is the operations and maintenance manual for the facility, which includes a description of the
facility, design calculations, material specifications for use in replacing materials as needed, plant
descriptions, recommended maintenance activities and schedule, and recommended inspection
checklists. Copies of the report were given to the Operations Department and to DEC so that DEC
could include these facilities in their inspection process that they use for regulated BMPs. Although
MSD owns and operates the Neighborhood-scale facilities, another set of eyes from DEC is prudent.
As with the Site-scale facilities, DEC inspected annually during the Pilot and will then revert to their
typical triennial inspection schedule. See Appendix L for a sample Neighborhood-scale Operations
and Maintenance manual.
One concern for the Neighborhood-scale facilities is that redevelopment activities in the drainage, or
tributary area might lead to construction sediment flowing into the facility. Therefore, knowledge of
planned construction in the area is essential to ensuring the facilities are protected through erosion
and sediment control and possibly blocking the inlets to the facilities during construction. This was
one of the reasons behind the Tributary Lot Agreements described in Section 2.8. The Tributary Lot
Agreements recorded on LRA-owned parcels draining to the facility require MSD review of the
planned project. MSD review is required so that MSD can determine if the planned imperviousness
is within the amount assumed in the design and so MSD can be prepared for possible construction
sediment. All development and redevelopment plans should be submitted to MSD as a matter of
course, but smaller developments, such as a single new home using an abandoned lateral connection
to the sewer, will sometimes fail to submit. In addition to the Tributary Lot Agreements helping
ensure at least redevelopment on currently LRA-owned properties will be submitted for MSD
review, MSD’s development plan review process includes looking for other projects near the
projects that come in for review. On MSD’s GIS mapping, a polygon surrounding all of the parcels
that are tributary to the Neighborhood-scale facility is shown to alert the reviewer that a
redevelopment project drains to the facility. The Development Review group can then alert the
Operations Department of the potential construction in the area.
The majority of the maintenance activities for the Neighborhood-scale facilities are being performed
by landscape maintenance contractors that have expertise in native plants and invasive species.
Routine maintenance activities such as trash cleanup and plant care are typically performed on a
monthly basis except for growing seasons (spring and summer) where mowing and weeding require
two visits per month on average. Annual tasks such as replenishing mulch and pruning are also
conducted by the maintenance contractors. MSD’s Operations Department staff assists on an as-
needed basis for sediment removal from the forebay, large debris removal, and inlet structure
cleaning. Operations staff also inspects the facilities monthly and oversees the maintenance
contractors.
Table 2.10 summarizes the maintenance periods and activities for the Neighborhood-scale facilities.
Samples of inspection and maintenance documents are provided in Appendix M.
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Table 2-10 Summary of Maintenance and Inspection Responsibilities for Neighborhood-Scale Facilities
2.12.4 Permeable Alley Sweeping
In addition to Neighborhood-scale bioretention maintenance, MSD also paid for sweeping one of the
City of St. Louis’s permeable paver alleys. This alley is being monitored as part of the monitoring
protocol developed for the Pilot, and described later in Section 2.15. The alley had not been
maintained since it had been constructed in 2011 and clogging and weed growth was evident
between the pavers. MSD’s cleaning and monitoring efforts provided a learning opportunity to
better evaluate the costs attributable to permeable alley maintenance and to observe how the
pavement performed before and after intensive maintenance. See Figure 2-21 for how the pavers
looked before and after the sweep.
MSD contracted for a vendor to do restorative maintenance on the pavement, which included power
washing and vacuum sweeping. The cost for sweeping the 10,670 square foot of permeable alley
was $18,750 or $1.76/SF. According to the vendor, if the alley was swept on a regular basis,
Inspection/Maintenance Responsibilities
Item Construction InspectorConstruction ContractorOperations Contract ManagerMaintenance ContractorOperations CrewsDECDuring construction
Erosion and sediment control X X
Routine maintenance X X
Plant replacement (paid for by Contractor) X X
60 day maintenance period (ends at final acceptance)
Erosion and sediment control X X
Routine maintenance X X
Plant replacement (paid for by Contractor) X X
1 year guarantee period
Routine inspections (quarterly) X
Erosion and sediment control maintenance X X
Routine maintenance X X
Plant replacement (paid for by Contractor) X X I
After 1 year guarantee period
Routine inspections X
Routine maintenance (plants, mulch and trash)X X
Routine maintenance (slight erosion repair & sediment removal)X X
Plant replacement (paid for by MSD)X X
Non-routine maintenance X X
Major maintenance X X
Annual inspection/maintenance reports*X X
Annual inspection X
I = Inform construction inspector of issues regarding plant condition, do NOT remove plants
Routine maintenance = weeding, watering, mulch replacement, vegetation, slight erosion repair, trash & sediment removal
Non-routine maintenance = major erosion repair, filter clogged at top (aerate), cleanout underdrain, cleanout structures/tideflex
Major maintenance = structure repair/replacement, tideflex replacement, remove and replace bioretention filter
*Submit annual inspection/maintenance report to Susan McCrary by March 31 for activity during the previous calendar year
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estimated at twice a year, the time to perform the sweep would be approximately half of what this
effort entailed, bringing the actual cost closer to $10,000 or $0.94/SF. Double-ring infiltrometer
testing from 2014 (before the sweep) to 2015 (after the sweep) showed a sharp increase in surface
infiltration from an average of 13.6 cm/hr in 2014 to 176.4 cm/hr in 2015 after the sweep.
Figure 2-21 Permeable Alley Before and After Sweep
Knowledge was gained on restorative, non-routine maintenance of the pavement and also on how
important routine maintenance is for porous pavement to ensure long-term performance.
2.12.5 Inspection and Maintenance Summary
During the course of the Pilot (prior to October 31, 2015), MSD conducted the following inspection
and maintenance activities on Pilot facilities:
Table 2-11 Inspections and Maintenance Activities (prior to October 31,2015)
Activity Occurrences
Neighborhood-scale Routine Maintenance (Maintenance Contractor)
Trash/Leaf Removal 236
Weed Planted Areas 203
Groom/Prune 21
Watering 75
Mulch/Fertilization 48
Mowing & Trimming 177
Other (Replanting, special clean ups, report preparation) -
Neighborhood-scale Inspections and Maintenance (MSD Operations Department)
Inspection 171
Install sign 5
Clean Forebay 1
Laid asphalt 1
Heavy debris 2
Flush trench drain 2
Flagstone repair 3
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Activity Occurrences
Replace CO Cap 1
Site restoration 3
Neighborhood-scale Inspections (MSD Division of Environmental Compliance)
Inspections 17
Site-scale Inspections (MSD Division of Environmental Compliance)
Inspections 47
Table 2-11 Inspections and Maintenance Activities (prior to October 31, 2015)
Planning for costs for maintenance of GI practices is critical for long-term performance.
Maintenance costs for the Neighborhood-scale projects were projected as 3-6% of construction cost
per year, as found in published literature (Erickson et. al., 2008). All of the costs for maintenance as
of October 31, 2015 can be found in the detailed expenditure information in Appendix Y. Included
here is information specific to 2014, which is when all of the Neighborhood-scale facilities were in
operation, and for which the entire year’s worth of data is available. During 2014, operation and
maintenance of the six Neighborhood-scale facilities amounted to $27,112.74. The total
construction cost for the facilities is $708,518.44, for a maintenance cost of 3.8% of the construction
cost for 2014. This cost is in line with the predicted cost. The following Table 2-12 summarizes the
Year 2014 activities and costs.
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Table 2-12 2014 Operations and Maintenance Activities and Costs OtherFacilityTotal Maintenance Cost
Construction Cost
Maint./ Const. Cost (%)
Trash/ Leaf Removal (#)
Weed Planted Areas (#)
Groom/ Prune Plants (#)
Watering (#)
Mulch/ Fertilization (#
Mowing & Trimming (#)
Extra
Cost
Inspection (#)
Install sign (#)
Clean Forebay (#)
Laid asphalt (curb inlet) (#)
Heavy debris removal
Flush Trench Drain (#)
Flagstone repair (#)
Replace Cleanout Cap (#)
Cost
Water Charge
Beacon Ave. Rain Garden in Walnut Park East4,083.59$ $128,355.12 3.2% 22 20 2 8 10 14 1,788.80$ 13 1 1 1 2,146.43$ 148.36$ Clinton St. Rain Garden in Old North 3,399.08$ $184,873.46 1.8% 15 12 1 0 1 122,375.00$ 13 1876.17$ 147.91$ Geraldine Ave. Rain Garden in Mark Twain6,046.13$ $92,214.86 6.6% 22 20 2 8 10 141,788.80$ 13 11 4,100.41$ 156.92$ N. Sarah St. Rain Garden in The Ville 4,999.78$ $123,782.50 4.0% 22 20 2 8 10 141,788.80$ 13 112,940.82$ 270.16$ N. Vandeventer Ave. Rain Garden in JeffVanderLou5,349.20$ $114,005.50 4.7% 22 20 2 8 10 14 Replaced 2 trees2,268.80$ 13 11 2,810.60$ 269.80$ Warne Ave. Rain Garden in O’Fallon3,234.96$ $65,287.00 5.0% 22 20 2 8 0 141,398.80$ 13 11 1 1,836.16$ -$ Totals27,112.74$ $708,518.44 3.8% 125 112 11 40 41 8211,409.00$ 78501123114,710.59$ 993.15$ Operations MaintenanceContractor MaintenanceTotals
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2.13 Public Education and Outreach
As opposed to most gray infrastructure practices that are out of site and out of mind, GI practices are
visible facilities that are interspersed among the community. As such, community acceptance and
support is critical to the success of any GI program. Moreover, input from the community is
essential in order to maximize potential community benefits, as further outlined in Section 2.14.
As noted in Appendix Q, page Q-3, “MSD will conduct public education/workshops and outreach in
neighborhoods where projects will be undertaken during the pilot phase. MSD’s pilot program will
utilize the existing public outreach mechanisms (including public input meetings, commission
meetings, public hearings, website and printed communications) of the participating City agencies to
conduct education and outreach to the extent such mechanisms ensure public understanding of
project plans and effectively solicit public input.”
To fulfill this requirement MSD reached out to various sectors of the community on numerous
occasions through face-to-face meetings, workshops, presentations, internet, social media, press, a
targeted public survey, as well as other means of outreach.
A detailed list of education and outreach efforts can be found in Appendix N.
2.13.1 St. Louis Development Corporation and Board of Aldermen
Throughout this 5-year program, from the planning stage to the post-construction stage, MSD has
worked with the SLDC, the umbrella not-for-profit corporation that includes the LRA, to inform the
City of St. Louis Board of Alderman (BOA) about the Pilot and to keep them apprised of projects in
their Ward. The LRA is a separate entity with its own Board. Although the LRA does not need
permission from the aldermen and alderwomen to sell property, they often communicate with the
aldermen/alderwomen and other departments within the City of St. Louis in order to gain input and
coordinate efforts.
At the beginning of the Pilot, SLDC and MSD conducted an informational meeting in August, 2010
where SLDC’s Executive Director and MSD’s Director of Engineering presented to the BOA
members in the Pilot Focus Area. As the Pilot continued, MSD and SLDC carried out additional
face-to-face meetings and correspondence with aldermen/alderwomen where Neighborhood-scale
meetings were planned.
2.13.2 Neighborhood Meetings
In MSD’s past experience with a variety of types of projects, when a meeting is scheduled for the
sole purpose of discussing a project, rarely are they well attended. Therefore, the District chose to
seek out other public forums in the areas surrounding the Neighborhood-scale projects with the hope
of reaching a broader audience.
The City of St. Louis is composed of 79 different neighborhoods, each with its own distinctive style
and characteristics. Some are on the rebound, while others have remained stable for decades, and
still others are striving for renewal. Many of the City of St. Louis’s neighborhoods have active
community organizations with regular meetings with the community, often in coordination with the
alderman/alderwoman and Neighborhood Improvement Specialist (also known as Neighborhood
Stabilization Officers) to discuss things that are happening in their community, concerns, solicit
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volunteers, etc. By asking to be placed on the agenda for these already scheduled community
meetings, MSD was able to get information about GI and the projects built in their respective
neighborhoods to a much larger audience. A community meeting was found in the neighborhood for
five out of the six Neighborhood-scale projects. No meeting was found to discuss the Geraldine
Avenue site in the Mark Twain neighborhood. However, the meeting in Walnut Park East, where
the Beacon Avenue site is located, took place very close to the boundary with the 1st Ward.
Therefore, both projects were presented at that meeting.
For simplicity, exhibit boards showing the project features were created for the meetings. At these
meetings, the Pilot project manager and usually the designer for the project did a short presentation
followed by questions and answers. Following is a list of neighborhood meetings attended, which
are also included in Appendix N.
Project Ward Organization Name Meeting
Date
Clinton St. Rain Garden in Old
North
5 Old North neighborhood meeting
5th Ward meeting
7/27/2013
10/1/2013
N. Vandeventer Ave. Rain Garden
in JeffVanderLou
3 3rd Ward meeting
The Ville (4th Ward) meeting
5/28/2013
9/5/2013
N. Sarah St. Rain Garden in The
Ville
4 The Ville (4th Ward) meeting 9/5/2013
Geraldine Ave. Rain Garden in
Mark Twain
1 Walnut Park East (27th Ward)
meeting
9/21/2013
Beacon Ave. Rain Garden in
Walnut Park East
27 Walnut Park East (27th Ward)
meeting
9/21/2013
Warne Ave. Rain Garden in
O'Fallon
21 O'Fallon Community Developing Org
meeting (21st Ward)
11/8/2014
Table 2-13 Neighborhood Meetings
The names of the Neighborhood-scale projects also adopted the name of the City of St. Louis
neighborhood in which the facility is located. This helped to connect the rain gardens to the
surrounding community.
2.13.3 Educational Signs
At each Neighborhood-scale project an educational sign, measuring 36” x 24”, has been installed.
Shown below is the sign installed for the Clinton Street Rain Garden in the Old North neighborhood
(Figure 2-22).
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Figure 2-22 Neighborhood-scale Faciltiy Educations Sign
2.13.4 Site-scale Owner Outreach
Ownership and Maintenance Brochure
For the Site-scale projects where the property owner is required to maintain the rain garden, MSD
developed an “Ownership and Maintenance” brochure for residential rain gardens and one for
residential planter boxes. The planter box brochure explains the purpose and function of the planter
box, lists a typical maintenance schedule, includes maintenance and inspections tips, and provides
photos of common weeds. The rain garden brochure contains similar information and includes
photos of native plants to use when replanting.
The brochures are available online on MSD’s website at:
http://www.stlmsd.com/sites/default/files/engineering/498692.PDF and
http://www.stlmsd.com/sites/default/files/engineering/498693.PDF (a copy can also be found in
Appendix O).
USEPA Urban Small Waters Grant
The previously described Habitat for Humanity Planter Boxes for the JVL project included 13
planter boxes in a development that previously installed rain gardens on 24 properties. Most houses
in the City of St. Louis have roof downspouts that are directly connected to the combined sewers.
This neighborhood, however, posed a unique opportunity to compare flows in the combined sewer
from a city block where nearly every house had a Site-scale GI facility with a block of homes whose
roofs were directly connected to the Combined sewer. The development also presents a challenge in
that there are 37 individual GI facilities, each with a different owner. Since the facilities are
privately owned, they are the responsibility of the property owner to maintain through a Maintenance
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Agreement recorded with the property. While the facilities themselves were functioning as intended,
most had not been cared for in a manner that would add to the aesthetic value of the property. For
example, some of the older rain gardens had been neglected to the point that they were barely
discernible from the lawn.
In April 2012, the EPA selected a proposal submitted by Southern Illinois University – Edwardsville
(SIUE), in partnership with MSD and the City of St. Louis, for an Urban Small Waters Grant. The
title of the grant, “Community Rooted Green Infrastructures for Urban Water Improvements”
focused on the Habitat for Humanity community.
Figure 2-23 Typical Rain Garden in JVL Neighborhood
In order to take advantage of the unique stormwater management scenario as well as to help address
the educational needs of the neighborhood, SIUE, in partnership with MSD, Habitat for Humanity,
and the City of St. Louis, applied for the Urban Small Waters Grant. Specific project activities, as
noted in the grant’s scope, included the following:
Flow monitoring and evaluating flow reduction
Developing materials for community outreach and public education
Delivering education workshops
Publicity
The monitoring and evaluation information can be found in Appendix Z with the rest of the Pilot
monitoring information. The educational components are included in this section. For a more
detailed description of the work completed and the results achieved, a copy of final report prepared
by SIUE, as submitted to EPA on July 30, 2015, can be found in Appendix P.
For the purpose of the grant, two sets of workshops were planned in 2013. Two workshops were
planned for the spring to help owners understand the reasons for the facilities and to talk about
spring and summer maintenance activities. Two workshops were planned for the fall to cover fall
and winter maintenance activities. Each of the sets of workshops covered the same information with
the intention that holding two times would give more owners a time that would work with their
schedule.
Figure 2-24 Typical Planterbox in JVL Neighborhood
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The spring workshops were held on Saturday morning, April 27, 2013 and on Tuesday evening,
April 30, 2013. To encourage participation, MSD included an invitation in letters sent to residents
whose rain gardens or planter boxes were determined to need maintenance based on inspection. In
addition, the City of St. Louis and Habitat for Humanity volunteers went door-to-door to invite
residents, provide a goody bag (which included items such as garden gloves, seeds, and a metal
water bottle), and administer a pre-test to measure the resident’s attitudes towards the GI facility.
Although the majority of the residents (32/37) said someone would attend one of the workshops,
only 7 residences were represented. However, the attendees indicated that they were more informed,
although they wanted more information on identifying and controlling weeds.
In addition to the workshops envisioned for the grant, the City of St. Louis took the lead in
organizing a “planting party” for mid-May 2013. The Missouri Department of Conservation
provided 145 plants. While bad weather resulted in a low-turnout and plants were only distributed to
the nine families in attendance, a Habitat for Humanity representative facilitated an impromptu
workshop in which the MSD representative was able to talk about the purpose of GI and residents
with successful rain gardens were able to answer questions about how to properly maintain them.
Based on feedback from the spring workshop participants and discussions with Habitat for
Humanity, it was decided to integrate the fall education activities into a Habitat for Humanity-led
block party. Two residents participated in a planning meeting and they suggested activities to
include for increased participation and volunteered
to assist with encouraging participation in the event.
The event was held on a Saturday morning,
September 14, 2013, on a street in the neighborhood.
Approximately 175 people, including children,
participated in the community block party.
Activities included a presentation on the purpose of
GI facilities, fall and winter maintenance of GI
facilities, the Enviroscape model, and the Rain
Maker demonstration that provides a visualization of
the effect of surface perviousness on stormwater
runoff. In addition to the MSD education activities,
there were multiple activities targeting children as
well as a DJ providing music and free food. Tables
by other community organizations were also included
such as The Home Depot, a local nursery, and a master gardener from the Missouri Botanical
Garden’s Master Gardener Program. The inclusion of the master gardener was a direct result of
feedback from residents who said they wanted assistance with identifying weeds and understanding
how to take care of the plants. In addition to answering questions, the master gardener led tours of
neighborhood rain gardens and planter boxes.
In an effort to quantify results from the block party, a pre-test and post-test was incorporated into the
event. The flyer for the event that included a pre-test as well as information about the event and a
raffle designed to encourage participation. After turning in a completed pre-test, a resident was
provided with a form on which to gather stickers from the three primary education activities. Once
Figure 2-25 Block Party Demonstration at the
JeffVanderLou Neighborhood
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a resident turned in a completed sticker form and a completed post-test, the person was entered in the
raffle. Prizes included two $50 gift cards to a local grocery, a large container of Roundup, and large
plants. All prizes were donated. In addition, MSD provided a plant to each resident who participated.
2.13.5 Project Clear Stakeholder Engagement Committee
MSD Project Clear is MSD’s platform for informing the community about the variety of work MSD
is undertaking under the CD. Project Clear has a separate website, www.projectclearstl.org,
including dedicated pages for the Early Action Grants and Rainscaping Small Grants programs, as
well as other information regarding “rainscaping.”
As part of the overall CD outreach efforts, MSD formed a committee known as the Project Clear
Stakeholder Engagement Committee (SEC). The SEC is made up of 51 representatives from
economic, religious, community, political, engineering, not-for-profit, and higher education
organizations from the St. Louis region. The committee meets quarterly and provides input on all
aspects of Project Clear, including the CSO GI Program. The SEC is a conduit for disseminating
information about Project Clear and the CSO GI Program to their respective communities through
newsletters and other communication vehicles. They are also an invaluable sounding board for hot-
button issues.
2.13.6 Websites and Blogs
MSD has included information on the Pilot and the CSO GI Program in two main online forums.
Static information is kept on the Project Clear website, www.ProjectClearSTL.org. This website
was set up to inform the community about the CD and the how MSD is addressing the region’s
sanitary sewer issues. It divides the work into three categories:
1. “Get the Rain Out” including the CSO GI Program as well as an extensive program for
disconnecting stormwater sources into the sanitary system.
2. “Repair and Maintain” efforts such as an accelerated schedule for cleaning and inspecting
and miles of pipes annually, and rehabilitating deteriorated pipes using cured-in-place pipe
lining techniques.
3. “Build System Improvements” includes wastewater treatment plant upgrades, sewer projects,
above ground storage tanks, and large deep tunnel storage projects.
The “Rainscaping” page on the website is where the information about the CSO GI Program is
located. There are individual pages for the “Rainscaping Small Grants Program” and the “Early
Action Program” which are covered in Section 3 of this report.
In addition to the Project Clear website, MSD has included several articles about the Pilot on its
blog, located on the main MSD website at: www.stlmsd.com/blog. On September 17, 2010, MSD
issued the first Pilot blog to announce the CSO GI Pilot Program:
LRA & MSD Announce $3 Million Pilot Green Program to Protect the Environment and Assist
Redevelopment
The City of St. Louis’ Land Reutilization Authority (LRA) and The Metropolitan St.
Louis Sewer District (MSD) have finalized an agreement for a $3 million pilot GI
program in the combined sewer portion of MSD’s service area. This pilot program
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is meant to help understand the regulatory, logistical, financial, and educational
challenges that will need to be managed as green infrastructure is utilized to address
sewer overflows. If successful, similar type programs may be implemented
throughout the St. Louis area.
Designed to reduce the amount of sewer overflow volumes that occur during
moderate to heavy rainfalls, thereby protecting local waterways, this program will
also assist redevelopment of vacant properties through the construction of
stormwater facilities that meet MSD’s current stormwater management
requirements.
Combined sewers handle both wastewater and stormwater through the same sewer
pipe and have a limited capacity. During moderate to heavy rainfalls, these sewers,
which serve both the City of St. Louis and large portions of St. Louis County, can
become overwhelmed by too much rainwater entering the sewer system. The result
of this “overcharging” is that sewer overflow points throughout the City and County
activate and act as relief valves. Without these overflow points, potentially hundreds
to thousands of basement backups could occur and miles of streets could
flood. Green infrastructure, such as the types that will be utilized in the LRA-MSD
pilot program, can lower the costs of addressing these overflows, improve overall
water quality, and add to the aesthetic value and quality of life in residential areas
throughout the St. Louis area.
Specific to the LRA-MSD pilot program, beginning in September 2010,
approximately 50% of the $3 million will be used to remove vacant structures from
approximately 200 LRA owned lots in North St. Louis City. LRA will manage
administration of these funds and the demolition process itself. As structures are
removed, MSD will utilize the remainder of the funds to build GI facilities on these
properties that reduce stormwater flows into area sewers. These facilities will
include rain gardens, pervious pavements, detention and micro-detention basins,
planter boxes, rain barrels, wetlands, and other types of GI that hold back or divert
storm runoff during rainstorms. The $3 million for this work is funded by MSD’s
sanitary sewer rates. Demolition is expected to be completed over the next several
months and construction of the green facilities will take place throughout 2011.
Another Pilot-related blog on the website was written on January 31, 2012:
MSD’s CSO Volume Reduction Green Infrastructure Pilot Program – Introduction
Green infrastructure is practices or facilities that reduce the volume, rate or pollutant
load of stormwater runoff before it goes into the sewer system and creeks. They do this
by capturing stormwater and diverting it to where it can be detained, infiltrated into the
ground, evaporated, taken up by plants, or reused. There are several types of green
infrastructure best management practices. These include:
Bioretention cells, planter boxes and other rain garden techniques
Amended soils, tree plantings and native plantings
Pervious pavements and green roofs
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Wet ponds and constructed wetlands
Tree trenches and native plantings
Rain barrels and other rainwater harvesting techniques
Combined sewers are pipes that carry both wastewater and stormwater which go to
MSD’s wastewater treatment plants during dry weather and small rain events. 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.
As part of MSD’s Combined Sewer Overflow Long Term Control Plan (CSO LTCP),
MSD is creating a green infrastructure program in the combined sewer area that flows
to CSOs along the Mississippi River. The purpose of the program is to reduce the
volume of stormwater runoff that enters the combined sewer system during rain events.
There are a number of challenges to launching a green infrastructure program. Where
to find land that could be used for green infrastructure in the target area? What kinds of
facilities work best for St. Louis? Who will maintain the facilities? MSD is working
through these challenges with a five-year pilot program.
The first hurdle was overcome with the help of the Land Reutilization Authority (LRA),
which is one of St. Louis City’s economic development authorities. The LRA owns about
10,000 properties. Many of these properties have abandoned buildings in need of
demolition, and many of the properties are in the target area for the green infrastructure
program. So, a partnership opportunity was born!
The green infrastructure pilot program works like this:
Over the past year, MSD funded the LRA’s program to demolish about 220
abandoned buildings, which reduces runoff in the short term by removing the
impervious rooftops and pavement on those parcels
In demolition and other agreed upon LRA owned locations, MSD will build green
infrastructure best management practices (BMPs) or will reserve areas for future
green infrastructure BMP construction
Larger “Neighborhood-scale” facilities built during the pilot program will be
owned and maintained by MSD
Smaller “Site-scale” facilities sized for a single lot will be in a BMP Reserve
Area, and these lots will be maintained by LRA and future property owners. All
reserve areas are recorded with a maintenance agreement that will transfer to
the new property owners
Demolition locations where it does not make sense to build a facility now will
have a development agreement recorded with the property for future green
infrastructure to be built in cooperation with redevelopment of the property
The projects built in the pilot program will be an opportunity to show the
community different green infrastructure practices, learn which practices are
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most desirable and collect information that will be used to create the broader
green infrastructure program
Why is MSD interested in a green infrastructure program? Besides being a cost
effective means for reducing the amount of runoff that enters the combined sewer
system, green infrastructure can also improve groundwater recharge, improve the
water quality of the runoff, enhance property values, and increase awareness of
stormwater and water quality issues.
More information on the green infrastructure program, including the pilot program,
can be found in MSD’s CSO Long Term Control Plan. Details of the green
infrastructure program can be found in Chapter 12 and Appendix Q.
For additional information on the green infrastructure pilot program, please contact
314-768-6260.
2.13.7 Social Media
MSD uses Twitter and Facebook to connect with the community through social media. Here are a
couple of examples of Pilot-related content.
Twitter (example August 18, 2014)
MSD St Louis retweeted
ProjectClearSTL @ProjectClearSTL · Aug 18 http://www.5citiesplus.org hosts
@CincinnatiMSD @CDPU #LouMSD @IndyDPW @YourMSD We're proud to show off our
rainscaping!
Figure 2-26 5 Cities Conference - Tour of Green Infrastructure Projects - Clinton Site
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Facebook
Figure 2-27 Example Project Clear Facebook Entry
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2.13.8 Press
Press Releases
MSD has issued a number of press releases and press events for local newspapers and TV stations
noting critical milestones. One such event was a dedication ceremony at the Clinton Street Rain
Garden in Old North St. Louis, the first Neighborhood-scale project completed in the Pilot. The
event included remarks by MSD’s Executive Director and received coverage by local newspaper and
radio.
Raingarden In Old North St. Louis Will Take Pressure Off Storm Drains
Brett Blume
July 25, 2013 12:30 PM
ST. LOUIS (KMOX) – It’s called “rainscaping”, and the Metropolitan St. Louis Sewer District is
willing to bet up to $100 million that it will be at least a partial solution to damaging stormwater
runoff.
“It helps us to manage stormwater before it gets into the sewer system,” said MSD executive
director Brian Hoelscher during a ceremony Thursday morning at the new raingarden in the city’s
Old North neighborhood (14th & Clinton). “It keeps us from having to build gray infrastructure —
bigger sewers, more sewers, pump stations, treatment facilities — by letting Mother Nature do what
Mother Nature does best.”
It’s all a part of Project Clear, the MSD’s 23-year, $4.7 billion initiative to plan, design and build
system-wide improvements to address water quality and alleviate wastewater concerns throughout
the St. Louis region.
Figure 2-28 St. Louis Post-Dispatch Article, December 30, 2011
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The Old North Raingarden will retain stormwater and slow its flow into the combined sewer system
and thus into MSD’s wastewater treatment plants.
The combined system, mostly in the city of St. Louis, carries both stormwater and wastewater in
contrast to the separate system in most of St. Louis County where runoff is designed to flow into
different systems.
“The more we can manage the rain on the ground through rainscaping techniques such as these, the
less we have to deal with in the combined sewers,” Hoelscher said.
He added that even in a so-called “20-year storm” of five-to-six inches of rainfall in a 24-hour
period, the Old North Raingarden is designed to manage so much water that the runoff will be as
though the entire city block were grass.
The Old North site is the first of six large Neighborhood-scale raingardens all located within MSD’s
Bissell Point watershed as part of the District’s consent decree with the Environmental Protection
Agency.
Four others are nearing construction, located in the JeffVanderLou, Ville, Mark Twain, and Walnut
Park East neighborhoods.
A sixth raingarden will be under construction soon in the O’Fallon neighborhood.
2.13.9 Targeted Public Survey
In July 2015, MSD commissioned an online survey in order to gather a better insight to the
community’s knowledge and reaction to GI. This survey was distributed to 575 individuals within
MSD’s entire service area, ranging from the District’s SEC and municipal leaders to individual
ratepayers. The survey’s main objectives were to gain feedback on:
Community reaction to rainscaping (GI)
Perceived benefits of GI
Perceived obstacle of GI
A copy of the online survey and detailed summary of results are provided in Appendix Q.
Between July 21 and July 28, 2015, the survey recorded 88 responses. This is a typical 5 to 10
minute survey sent via email and requires respondents to click through to complete the survey. A
survey of this type generally generates a response rate of 2% to 3%. By comparison, this survey’s
response was 15.3% – clearly indicating a determinedly interested audience.
Overwhelmingly, those surveyed are both familiar with and support Rainscaping projects. With the
exception of “Wetlands”, the types of projects that individuals expressed familiarity with were more
likely to be those kinds of projects they supported in their own neighborhoods. Respondent
familiarity with “Wetlands” exceeded support for installation of Wetlands in their neighborhood by
the greatest margin (52 familiar vs. 43 support). Familiarity also exceeded support for “Permeable
Pavements” (70 familiar vs. 69 support) and “Rain Barrels” (77 familiar vs. 75 support), though only
slightly.
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Despite the high familiarity with and support of Rainscaping projects, respondents did not believe
many of these project types were in their neighborhoods – “Street Trees and Curb Plantings” were
identified most as in their neighborhood (40/88), though still less than half indicated they were
present. Twenty-six (26) of the respondents indicated that no Rainscaping was present in their
neighborhood at all (30%).
The single greatest obstacle that respondents identified to Rainscaping in their area was “Lack of
information/awareness” – though it seems to be the awareness available to others that was their main
concern. This is indicated by the overwhelming number of individuals that indicated familiarity with
the term “Rainscaping” (72/88) and by the very small number of individuals who were unfamiliar
with any type of Rainscaping project (4/88).
One quarter of survey respondents live within the CSO GI Program Area (22/88) and of those
respondents, only one was unfamiliar with Rainscaping and did not believe it could provide any
benefits to their neighborhood. Only one of these respondents indicated they would not support the
installation of Rainscaping in their neighborhood. There was no significant difference in the
percentage of CSO GI Program Area respondents who thought there was no Rainscaping in their
neighborhood or did not know whether there was Rainscaping.
Of those respondents in the Rainscaping Focus Area, only two were not familiar with the term
Rainscaping – much less than the total group (9% vs. 18%). This is an encouraging statistic in
familiarity with the project types. However, individuals were more likely to indicate that “No
Rainscaping projects” were present in their neighborhood (37% vs. 30%). This may be explained by
the fact that there are relatively few installed Rainscaping projects in the CSO GI Program Area and
even fewer are in high-traffic areas. Still, this represents an opportunity for public engagement and
education on the existence of projects within neighborhoods.
In conclusion, this survey represents a brief snapshot into a universally positive community
perception of and support for Rainscaping/GI. Areas for growth include community awareness of
Rainscaping projects’ presence in their neighborhood and availability of information on Rainscaping
to the community in general.
2.13.10 Other Outreach Activities
The maintenance contractors have proven to be great ambassadors for the GI practices. Since they
are at the Neighborhood-scale sites at least once a month, they receive many impromptu comments
from neighboring property owners. Instead of having a run-down dilapidated house next to them,
the adjacent property owners have voiced that they are delighted to see a significant and positive
improvement. They acknowledge that the GI sites go beyond being aesthetically pleasing; they are
well aware that the improvement has a positive impact on their property value. Plus, they recognize
that these sites are well maintained.
The maintenance contractors document comments that they receive from property owners in their
monthly reports that are submitted to MSD. Below are sample excerpts from those monthly reports:
N. Sarah site – the neighbor is ecstatic about the improvement
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Beacon site – the neighbors love the improvement and even more so since a large established
tree was not removed. The site gets lots of pedestrian traffic.
Beacon site – the Neighborhood Stabilization Officer (NSO) stopped by and noted her
support
Additional presentations have been made at a wide variety of events. Some are community
organizations interested in more information, some are more technical audiences within the St. Louis
landscaping and engineering community, and still others were national conferences or an
informational booth. The venues included:
St. Louis Earth Day Symposium
City of St. Louis Mayor’s Sustainability Summit
Green Business Exposition
5 Cities Plus Conference
Environmental & Water Resources Institute’s World Environmental & Water Resources
Congress (American Society of Civil Engineers)
Shaw Professional Landscaping Series (Missouri Botanical Gardens)
St. Louis University Engineering Department
Home Builders Association
River Rally
The entire list of public outreach presentations and meetings with elected officials is provided in
Appendix N.
2.13.11 Public Education and Outreach Lessons Learned
As stated earlier, the success of any CSO GI Program relies on buy-in and acceptance of the
community. Knowledge and acceptance brings new opportunities for incorporating GI into the
landscape and helps to build upon the effort to incorporate more sustainable practices into new
development and redevelopment practices.
Some of the key lessons regarding public education and outreach are as follows:
In order to reach the community in the Program Area, considerable time in face-to-face
meetings with aldermen/alderwomen, community group meetings, individual meetings with
interested parties, and others is required in order to get the most inclusion possible into the
CSO GI Program.
Utilizing the City of St. Louis and its networks, including LRA and the Neighborhood
Improvement Specialists, can be an effective way to find out about possible community
meetings and get on the agenda.
LRA is a valuable resource for communication with the City of St. Louis BOA and other
City of St. Louis departments.
Educating private homeowners about GI facilities on their individual properties is a time
consuming task with mixed results and will need to be repeated periodically as property
changes hands. One-on-one time with experts in plant design, maintenance, and weed
identification, such as Master Gardeners, appears to be a more effective strategy than some
others attempted.
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2.14 Potential Community Benefits
As stated in Section 12 of the CSO LTCP, in addition to reducing wet weather flows, GI 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 GI as an appropriate
element of LTCPs is becoming increasingly common all across the country.
One aspect of GI 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 GI 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 conventional engineered drainage systems.
Major costs of GI are acquisition of land and system installation (Field, 2009). Green solutions can
provide insulation for buildings and mitigate urban heat island effects, thereby decreasing utility
costs. Although conventional systems may initially be less expensive, they require more in terms of
maintenance throughout their life cycle. By comparison, the overall life cycle cost of green
technology can be much less than conventional systems.
Finally, GI 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. GI
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, 2014).
In order to more specifically identify those potential benefits in the CSO GI Program Area, MSD
retained SIUE to perform a study of GI-related community benefits. The scope of SIUE’s study
included:
Reviewing literature of up to 15 large metropolitan sewer districts or municipalities in the
United States and internationally that have or plan to incorporate GI;
Utilizing information obtained in the literature review combined with input from MSD staff
to determine lessons learned of relevant benefits;
Gathering data from local agencies on socio-economic conditions of the CSO GI Program
Area, such as population density, age, property value, gross income per capita, household
income per capita, educational level of head of household, employment situation, registered
unemployment rate, and crime rate for the Bissell service area; and
Summarizing findings in report format that specifically focused on environmental, social,
and economic benefits in the neighborhoods surrounding recently constructed GI facilities.
The City of St. Louis’ Planning & Urban Design Agency (PDA) provided electronic datasets
containing the socio-economic categories mentioned above.
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The full Community Benefits report by SIUE can be found in Appendix R. A summary of potential
community benefits of the CSO GI Program are as follows:
Social
o Improvement of community livability
o Enhancement of physical and mental health
o Improvement of quality of life
o Increases awareness of stormwater and water quality issues
Environmental
o Reduction of urban heat island effect and heat stress
o Enhancement of urban nature aesthetics
o Increased recreational opportunities
o Equitable access to healthy neighborhoods
o Improvement of air quality
o Reduction of flood events
o Reduction in combined sewer overflow volume
Economic
o Creation of “Green” jobs
o Reduction of energy bills
o Increase in property values
o Increase in tourism and opportunities for local small businesses
o Reduction of costs for wastewater treatment facility
2.15 Monitoring
One of the main objectives of the Pilot is to evaluate project effectiveness by monitoring selected GI
projects. This means monitoring stormwater runoff volumes from the project sites and computing
estimates of runoff volume reduction based upon hydrologic modeling of the drainage area to each
project. The focus of the monitoring is solely on the hydrologic benefit, specifically runoff volume
reduction of the GI element. The data collected during the Pilot is used to help predict the expected
runoff volume reduction value of future GI projects.
The monitoring program was laid out in accordance with the “CSO Volume Reduction Green
Infrastructure Pilot Program Monitoring Protocol” (LimnoTech, October 2012) report submitted to
EPA on November 1, 2012. The Monitoring Protocol can be found in Appendix S.
2.15.1 Pilot Project Monitoring Locations:
To determine the monitoring locations, the planned Pilot projects were reviewed to identify which
should be monitored. The factors considered included the total number of projects identified of each
project type, size of the project drainage area in order to monitor a range of project sizes, and unique
aspects of the projects. The following projects were selected:
Project Type Project
Number Location Scale Rationale for Monitoring
Porous Alley* 11787 Clinton St / N 13th St Neighborhood Sole porous alley pilot
project
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Bioretention 11778 2818 N
Vandeventer
Neighborhood Largest bioretention
project
Bioretention 11802 5099 Geraldine Ave Neighborhood Small bioretention
project
Amended Soil Package #1 4228‐4240 Warne
Ave
Site‐Scale
Multiple Lots
Represents soil package
#1
Amended Soil Package #2 3832‐3834 Labadie
Ave
Site‐Scale
Multiple Lots
Represents soil package
#2
Rain Garden P‐29210 1451 Monroe St Site‐Scale
Multiple Lots
Most accessible rain
garden pilot project
Planter Boxes P‐28660 Habitat for
Humanity: 2940‐
2957 Thomas St;
2942 Sheridan Ave;
1341 Garrison Ave
Site‐Scale
Multiple Lots
MSD/SIUE already
monitoring, represents
basic planter design
*The Clinton Street alley project was later dropped from the Pilot . Therefore, an alley that had been constructed by the
City of St. Louis was monitored in order to gain insight into this form of GI. The alley is located from Spring Ave. to
Grand Blvd. between Humphrey Avenue and Utah Avenue (Project Number P-0029066-00).
Table 2-14 Pilot Monitoring Locations
2.15.2 Monitoring Approach:
The basic monitoring approach is to collect sufficient data for calculation of runoff volume reduction
or peak rate reduction. The key elements include:
Rainfall monitoring using MSD’s array of rain gages near Pilot projects and radar rainfall
data adjusted using the rain gages to provide spatially continuous rainfall coverage. The
rainfall data is then used to characterize rainfall events associated with measured flows at
each GI project and to calculate runoff to the GI project. In cases where both storage and
outflow (determined from depth/velocity measurements) are measured, such as with
bioretention projects, the rainfall-derived runoff volume can be compared to runoff volume
calculated from monitored outflow and storage volumes. For projects where only outflow is
monitored, such as with rain gardens, the rainfall is used to calculate runoff flows to the
projects.
Storage monitoring – for the bioretention projects, understanding the change in storage over
time within the project is monitored by recording the stage using a level logger in both the
underdrain and at the surface of the basin.
Outflow monitoring – Outflow determined from depth or velocity measurements is
measured where possible in order to determine the reduction in peak flows and volumes
from the GI projects.
Infiltration testing – Surface infiltration is measured using a double ring infiltrometer
according to standard methodologies (ASTM D3385-09) to determine the rate water can
enter the surface of the GI features. In order to provide consistency in the infiltrometer
testing, a work plan was developed by M3 Engineering Group, P.C. A copy of the work
plan can be found in Appendix T and a copy of the final Double Ring Infiltrometer Testing
Results report, which includes results from all three annual tests, can be found in Appendix
O.
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Inflow modeling – Monitoring of runoff flowing into the Pilot projects would be impractical
due to multiple inflow locations as well as overland flow. Therefore, MSD developed
hydrologic models of the drainage areas contributing stormwater runoff to the Geraldine and
Vandeventer bioretention areas, the Monroe rain garden, and the Humphrey permeable
alley. MSD developed these models using the U.S. Army Corps of Engineers’ HEC-HMS
model platform to simulate runoff to the projects.
2.15.2.1 Bioretention Cell Monitoring
The bioretention cells at Geraldine and N. Vandeventer each incorporated the following monitoring
approach:
The surface infiltration rate into the bioretention soil media was measured using a double ring
infiltrometer annually in 2013, 2014 and 2015. Inflow volume into the bioretention basin is
calculated using drainage area characteristics entered into HEC-HMS to simulate runoff. Outflow is
directly measured using a monitoring manhole equipped with a flume between the overflow structure
and the combined sewer manhole. The elevation in the flume is measured with an ultrasonic flow
meter taking depth measurements at a 5-minute interval. To measure the change in storage, a level
logger is installed in the clean-out for the underdrain as well as at the surface of the basin.
2.15.2.2 Porous Alley Monitoring
The porous alley between Humphrey Avenue and Utah Avenue was monitored using the following
approach:
The alley is a permeable interlocking concrete pavement (PICP) blocks over a 2” thick ASTM No. 8
bedding (also used for joint aggregate) over a 4” thick ASTM No. 57 base aggregate over an 18”
thick ASTM No. 2 sub-base aggregate for storage. The surface infiltration rate was measured using
a double ring infiltrometer annually in 2013, 2014 and 2015. The infiltrometer was sealed to the
pavement using a waterproof sealant between the inside and outside of each metal ring. Inflow
volume onto the alley is calculated using drainage area characteristics entered into HEC-HMS to
simulate runoff. Outflow is directly measured using a bubbler flow meter with a Thel-Mar weir
taking depth measurements at a 5-minute interval.
2.15.2.3 Rain Garden Monitoring
The rain garden at 1451 Monroe Street was monitored using the following approach:
Inflow volume onto the alley is calculated using drainage area characteristics entered into HEC-
HMS to simulate runoff. Outflow is measured with the use of a v-notch weir installed lower than the
underdrain seep into the overflow weir, in order to capture both the underdrain and overflow volume.
The v-notch weir has a stilling well with a level logger installed to measure the stage in the weir at 5-
minute intervals. Due to the small footprint and dense vegetation of the rain garden, infiltrometer
testing was not feasible.
2.15.2.4 Planter Box / Rain Garden Monitoring
As described elsewhere, the planter boxes were installed in a Habitat for Humanity development in
the JVL neighborhood where several previously constructed houses included an individual rain
garden for each house. This gave a unique opportunity to compare flows in the combined sewer
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servicing a block with an individual GI facility on nearly every lot to another block where roof
downspouts were directly connected to the combined sewer.
The “treatment” site with the rain gardens and planter boxes was the block bounded by Sheridan
Avenue to the north, Thomas Street to the south, Glasgow Avenue to the east and N. Garrison
Avenue to the west. The block includes 24 houses, 18 of which have either a planter box or rain
garden, and 12 vacant lots.
The “control” site selected is the block east of Thurman bounded by McRee to the south and Blaine
to the north. The block includes 34 houses. Area-velocity flow meters were installed in the
combined sewers servicing each block. The dry weather flow was removed from the flow data as
base flow and the stormwater volume was normalized to account for the difference in drainage areas
and rainfall at the two sites. Detailed information about the study conducted with SIUE can be
found in Appendix P.
2.15.2.5 Amended Soil Monitoring
The amended soil sites were monitored using the following approach to try to determine soil water
storage. Infiltrometer testing was done at 6 locations for each site. Two tests in the compost
amended area, two tests in the core aeration and top dressed with amendments area, and two tests in
the area not amended. Tests were conducted in 2013, 2014, and 2015. In addition, two water level
wells were installed at each site, one in the compost amended area and one in the core aerated and
top dressed with amendments area. Each well was equipped with a level logger. In addition, a more
subjective monitoring was conducted by going to the site and assessing the vegetation in the various
areas as well as using a spade to take a wedge of soil and measure root depth. Inspection results
from this subjective monitoring can be found in Appendix V.
2.15.3 Semi-annual monitoring assessments
MSD and LimnoTech staff reviewed the monitoring data and evaluation every six months in order to
discuss issues and resolutions and determine if additional monitoring at the individual sites was
warranted. See presentations from those assessment meetings in Appendix W.
At the first semi-annual monitoring assessment, a recommendation was made for direct testing of the
bioretention facilities and Monroe rain garden site. The objectives of the testing were primarily to
verify system behavior, such as checking for inlet structure bypassing, short-circuiting, and other
related system behaviors; and to check inflow calculations. Secondary objectives were to verify
system performance parameters such as overall infiltration rates, volume required to generate
outflow, and other related performance parameters; and to provide synthetic event data to
supplement the actual rain events available. Direct testing using a fire hydrant for the bioretention
facilities and a garden hose for the Monroe rain garden site was conducted in October, 2014.
2.15.4 Monitoring Results
MSD monitored the outflow of six project sites from 2013 to 2015. The program successfully
collected data to inform MSD of expected runoff volume reduction from various GI practices. The
monitoring data recorded during the Pilot is provided in Appendix EE. A summary of the
monitoring program results is as follows:
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6 pilot project sites were monitored, 2 bioretention sites, 2 amended soil sites, 1 rain garden,
1 permeable pavement alley project;
Additional direct testing with fire hydrant or water hose was conducted on the 2 bioretention
sites and 1 rain garden site
Statistical models were created for the bioretention sites and the permeable pavement alley
project from the monitoring data;
The amended soil sites had inconclusive results from the monitoring data;
During the LTCP typical year 2000 rainfall, the statistical model estimates a runoff volume
reduction of 96% for the bioretention sites;
During the LTCP typical year, the statistical model estimates runoff volume reduction of
92% for the permeable pavement alley project;
The rain garden had an observed runoff volume reduction of 95% during the monitoring
period; and
Reports from SIUE for the planter box sites indicate between 55% and 65% runoff volume
reduction.
2.15.5 Monitoring Lessons Learned
Monitoring – Flumes
The first six months of the monitoring program at the Vandeventer and Geraldine bioretention sites,
the Monroe rain garden, and the pervious alley at Spring Avenue resulted in very little usable data.
All of these monitors utilize a flume for flow measurements. As discovered during routine
inspection visits, there is a quick buildup of debris in the flumes and behind the weir which disrupts
the flow elevation, hence, leading to unusable data. To rectify this situation, the Operations
Maintenance crews and Monitoring staff coordinated inspections of these sites. Inspection of the
equipment was revised so as visits would be made within 24 hours after a storm event. In addition,
inspections were made more frequently to ensure that good data would be obtained for use in
determination of the effectiveness of these facilities.
Other lessons learned from monitoring stormwater runoff during the Pilot include:
Monitoring wells for amended soil sites should not be much deeper than the amendment
depth to provide consistent measurements
Monitoring equipment can hold water for extended periods attracting nuisance pests such as
mosquitos
Monitoring equipment in storm pipes are vulnerable to damage by varmints such as raccoons
Controlled tests with fire hydrant flow provides ability to validate flow monitoring
2.16 Annual Reports
MSD submits an Annual Report to the EPA by October 31st of each year for the previous calendar
year with program updates, progress summaries, projections of work for the following year, and data
tables. MSD has included progress toward the CSO Control Measure “Green Infrastructure Program
– Pilot Program” in the Annual Report since 2011. Also included in the Annual Report is a table
reporting the status of the CSO GI Program Costs, including the Pilot and Early Action Programs
(described in Section 4). This table is a summary table showing expenditures by year and cost
category, as outlined in the LTCP, and below in Section 2.17. MSD also included a detailed table
for each project and other cost groupings such as Operation and Maintenance for the reporting year
during the Pilot. See Appendix X for an example of the applicable sections of the Annual Report.
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2.17 Project Accounting
The LTCP Appendix Q contains specific information about what types of expenses will be allowed
under the CD CSO Control Measures Performance Criteria. Documentation of the expenditures
made by MSD in connection with the CSO GI Program during the Pilot phase were maintained and
submitted for approval on an annual basis. The following categories of costs were tracked, reported
on, and count toward MSD’s $3 million GI Pilot phase commitment (which is included within the
$100 million full-scale implementation commitment):
Engineering
Soils assessment and/or restoration
Legal costs associated with deed restrictions and/or easements,
Property acquisition
Demolition
Construction of GI
Maintenance of GI
Public participation activities
Monitoring of GI practices and associated laboratory analyses
Identification of potential community benefits
MSD’s Oracle-based Enterprise Business System was used to track almost all of the Pilot
expenditures according to the project number and task number associated with the category. For
example, a Neighborhood-scale project has a task dedicated to external engineering costs,
construction costs, and internal design labor costs. The exception was internal labor and material
costs for operation and maintenance of the MSD Neighborhood-scale facilities, which are tracked
through MSD’s asset management system, Maximo. As part of the annual reporting during the Pilot,
a detailed expenditure breakdown by project for that year was prepared.
Following is an accounting of the expenditures made during the Pilot showing MSD exceeded the $3
million commitment by $842,198. A breakdown of the Pilot costs by project is provided in
Appendix Y.
Engineering $ 990,484.55
Soils Assessment and/or Restoration $ 382.00
Legal Costs associated with deed restrictions and/or easements $ 18,494.47
Property Acquisition $ 2,616.00
Demolition $1,500,000.00
Construction of Green infrastructure $ 887,379.89
Maintenance of Green Infrastructure $ 56,445.84
Public Participation Activities $ 55,863.03
Monitoring of Green Infrastructure practices and associated laboratory
analysis $ 319,879.92
Identification of community benefits $ 10,652.46
Total Expenditures $ 3,842,198.16
Table 2-15 Pilot Program Expenditures
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2.18 Conclusions
Starting in 2010, MSD began implementation of the Pilot in accordance with the LTCP, Section 12
and Appendix Q, in order to inform decision-making for the full scale CSO GI Program. The Pilot
has given MSD the opportunity to plan for anticipated regulatory, logistical, and financial aspects of
the CSO GI Program among the multiple stakeholders.
Over the past five years, MSD has:
Exceeded the committed expenditure amount of $3 million;
Negotiated an agreement with the LRA to fund demolition of dangerous buildings in
exchange for locations to build demonstration GI facilities;
Conducted public education and outreach, especially in the neighborhoods where projects
were constructed, in order to inform the community and solicit input;
Conducted a targeted survey to continue the process of soliciting input from the community;
Identified the community benefits associated with GI implementation in the MSD service
area;
Identified a diversity of GI facilities using property owned by the LRA, or that had been
owned by the LRA at the start of the Pilot;
Recorded Development Agreements against the deeds of properties with demolitions funded
MSD, to retain the benefit from the reduced impervious surface and setting the stage for
future GI facilities when those parcels are re-developed;
Designed and constructed GI facilities or reimbursed others for their construction;
Developed internal processes for designing and constructing MSD-owned GI facilities;
Developed internal processes for maintaining MSD-owned GI facilities as District assets;
Worked with existing processes for reviewing, inspecting, and enforcing Maintenance
Agreements on non-MSD owned GI facilities;
Monitored selected facilities to determine effectiveness in reducing runoff volume to the
combined sewer.
Developed methodology to extrapolate the runoff volume reduction to CSO volume
reduction; and
Met the CD Appendix D performance criteria for the Pilot.
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3 PERFORMANCE EVALUATION
The requirement for MSD’s CSO Volume Reduction Green Infrastructure Program (CSO GI
Program) is to spend a minimum of $100 million, including a $3 million CSO Volume Reduction
Green Infrastructure Pilot Program (Pilot) for costs outlined in this document and the CSO Long-
Term Control Plan (LTCP). The motivation for those costs is to reduce stormwater runoff with the
intent of reducing Combined Sewer Overflow (CSO) discharge volume to the Mississippi River
during the typical year, as defined in the LTCP. A primary goal of the Pilot was to inform the
performance goals and criteria which define a successful program.
3.1 Performance Considerations
3.1.1 Runoff Retention
The CSO GI Program directly increases runoff retention for the drainage areas managed. The
captured runoff is partially or completely infiltrated to the ground, permanently removing it from
entering the Combined Sewer System (CSS). This has the effect of reducing the discharge volume
of CSOs. MSD has experience implementing runoff volume reducing Best Management Practices
(BMPs) and green infrastructure (GI) in the Separate Storm Sewer System areas and select
Combined Sewer areas since 2006.
As such, MSD already had rules and regulations governing the design of such BMPs and
mechanisms in place which enforce their operation and maintenance. The current design standard
used in the Pilot and enforced throughout the District is intended to treat the water quality storm, or
the 90% non-exceedance 24-hour storm depth of 1.14 inches was used in the Pilot. This design
standard targets the removal of suspended sediments and is essential to water quality within the
Separate Storm Sewer systems. The current design standard is intended to mimic natural hydrology,
minimizing increases in annual runoff volume from new development, which equivalently converts
the drainage area to a GI facility to perform as green space.
The design of GI for the 90th percentile storm is not an essential priority for Combined Sewer areas
as low flows will be treated at a wastewater treatment facility, thus meeting water quality standards.
With the overall goal of CSO Volume Reduction in mind, it follows that the largest benefit to the
Combined Sewer System will come from maximizing drainage area managed, with the particular
design storm depth of secondary importance. Urban environments have limited available space for
GI facilities, so in order to maximize area managed without exceeding the GI footprint allotted to a
particular site, it may be desirable for the design storm depth to be reduced. MSD believes that
runoff volume retention during the more frequent smaller wet weather events could also have
benefits for reducing CSO discharge volume. Therefore, MSD intends to use an adaptive
management strategy in implementing GI design standards within the Combined Sewer areas such as
to permit alternative designs to maximize drainage and impervious area managed. It is expected that
any alternative design will have the maintenance capacity and runoff volume reduction benefit
reasonably quantified.
3.1.2 Peak Flow Control
Green Infrastructure also has the ability to limit the rate at which runoff can enter the sewer system.
A reduction in peak flow has the benefit of reducing the required conveyance capacity of a sewer
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and can reduce the frequency and discharge volume of CSOs. This function can be realized at all GI
facilities and is an important benefit which may be significant even without runoff volume reduction.
3.1.3 Pilot Program Monitoring Results
MSD conducted monitoring per the Monitoring Plan of the outflow at the following seven Pilot
project sites from 2013 to 2015:
Geraldine Bioretention Project
Vandeventer Bioretention Project
Monroe Street Rain Garden Project
Warne Avenue Soil Amendment Site
Labadie Avenue Soil Amendment Site
Humphrey Permeable Alley
Habitat for Humanity Planter Boxes and Rain Garden
The monitoring program was able to successfully collect data to inform MSD of expected runoff
volume reduction from the various GI practices. A monitoring report with site locations and detailed
descriptions of the monitoring data and statistical inferences from it are provided in Appendix Z,
with electronic data provided in Appendix EE and summarized herein.
Evaluation of monitoring data from the bioretention sites indicates that the two projects performed
very well and produced high rates of runoff capture. The data from the two bioretention sites was
combined into a statistical regression model based on event rainfall depth. Application of the
regression model to the typical year predicted an annual runoff reduction of approximately 96%.
The monitoring at the amended soil sites did not produce enough data to evaluate runoff reduction.
Between the two sites, only three observed rainfall events generated an observed response in the
monitoring well. Due to the limited quantity of available data, MSD was not able to make a
prediction of the potential runoff volume reduction for amended soil practices.
The Monroe Street Rain Garden Project monitoring data was insufficient to develop a statistical
model upon which to make predictions of runoff volume reduction during the LTCP typical year
rainfall. It was found through the observed data however that for the 128 events captured by
monitoring, runoff volume was reduced by approximately 95%. This result, similar to that of the
bioretention sites, suggests that rain gardens have the potential to be highly effective at runoff
volume reduction.
The Humphrey Permeable Alley monitoring data was used to create a similar statistical model to that
created for the bioretention sites using event rainfall depth as the model parameter. The statistical
model applied to the LTCP typical year predicted a runoff volume reduction of approximately 92%,
suggesting high level of performance.
Data from the Habitat for Humanity Project has been collected and evaluated by the Department of
Civil Engineering at Southern Illinois University Edwardsville (SIUE), under the direction of Dr.
Jianpeng Zhou. The findings of the SIUE study have been published in the Proceedings of the
World Environmental and Water Resources Congress in 2014 and 2015 (Bloorchian, et al., 2014 and
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Bloorchian, et al., 2015). The SIUE researchers found that at the block scale, the planter box and
rain garden techniques resulted in 55% to 65% capture of stormwater.
Overall, for each GI practice which yielded monitoring results for runoff volume reduction, it was
found that performance is very good and higher than typically reported in other literature (e.g. Davis
2008, Hunt et. al. 2006, Li et. al. 2009). Recognizing also that underlying soil conditions may vary
widely and to reflect a more sustainable level of performance over the lifetime of a particular GI
practice, MSD has decided to use an annual runoff volume reduction of 70% during the LTCP
typical year rainfall. This value is consistent with other observed values reported by others. MSD
also performed hydrant tests, described in Appendix Z, which flooded the bioretention basins with a
volume greater than any of the observed events. The hydrant tests also found that the Vandeventer
bioretention facility reduced the volume by approximately 70% and the Geraldine bioretention
facility removed 100% of the volume. Since MSD has monitoring data suggesting that all practices
monitored can perform at levels much greater than 70%, it is a conservative value which can be
uniformly applied across the CSO regions.
3.2 Initial Performance Estimate
While the Consent Decree (CD) requirement for the CSO GI Program is monetary, the purpose and
goal of the CSO GI Program is CSO Volume Reduction through runoff management. Therefore,
MSD desires to evaluate the performance of GI based upon criteria relevant to MSD’s CSO control
measures. Two metrics which were identified in the CSO LTCP as compatible with MSD’s long
term CSO control measures are the amount of impervious area managed or removed, and the
reduction in CSO volume during the typical year.
Impervious area managed or removed was considered a strong indirect metric relevant to the long
term goal of CSO Volume Reduction because it is directly proportional to runoff entering the sewer
system and easily measured. The CSO Volume Reduction was also an obvious metric because it
represents the ultimate goal and is easy to estimate through hydraulic modeling. The LTCP initial
estimate for CSO Volume Reduction during the typical year after the expenditure of $100 million
was 85- 222 million gallons (MG) with the intent to revise that estimate at the completion of the
Pilot Program.
3.3 Hydraulic and Hydrologic Modeling
One significant purpose and outcome of the Pilot is the development of a technique to connect GI
practices to the CSO LTCP collection system XP-SWMM model. MSD will use the collection
system model developed for use in the LTCP to compute the effect of GI on the CSO discharge
volume during the LTCP typical year. MSD identified within the model 12 geographical regions
served by Combined Sewer Systems draining to the Mississippi River which are both hydraulically
and hydrologically independent of each other, meaning the systems had no cross-connections in the
sewers or intersecting overland flow paths.
For each of the 13 regions identified in Section 1.7, the runoff and CSO volumes during the typical
year rainfall were related to a model land cover parameter. Relating runoff and CSO volume to a
model land cover parameter assisted MSD in connecting GI practices to the collection system model
similar as with other communities (EPA 2014). A detailed presentation of the methods used by
MSD in relating GI practices to CSO Volume Reduction is presented in Appendix AA. The ultimate
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result of that analysis is a parameter which relates acreage of area managed by GI practices to CSO
Volume Reduction and is presented in Table 3.1.
It should be noted that the analysis presented within Table 3.1 does not include the Lemay North
Region. It is recognized by MSD that there may be opportunities for GI available within that
particular drainage, however due to the interconnectedness of the sewer system within the Lemay
service area, there was not a directly identifiable way to separate the impact of GI on the Mississippi
River from its impact on the adjacent CSOs to the River Des Peres and its tributaries. As such, those
areas were not ranked with the Bissel Point service area drainages. It is believed that since the total
CSO volume to the Mississippi River in the Lemay system is less than 10% of the total during the
typical year, and that the areas which do directly contribute to those overflows are in a narrow strip
of land along the Mississippi River, that the impact of GI in Lemay will be at or below average
compared to the Bissel service areas.
CSO Region Efficiency Parameter
(MG/Acre)
Normalized
Efficiency Parameter
Central 0.320 1.385
Gimblin 0.271 1.176
Southern Arsenal 0.250 1.084
Utah 0.247 1.071
Louisa, Trudeau, Barton 0.238 1.033
Entire Mississippi River CSO
Drainage 0.231 1.000
Dakota 0.208 0.903
Rocky Branch, Salisbury 0.198 0.860
Harlem Creek 0.186 0.806
Humboldt, Baden 0.182 0.788
Ferry 0.135 0.585
Prairie 0.129 0.561
Biddle, Chambers South
Benton 0.126 0.548
Table 3-1 Efficiency Parameter for CSO Regions
The parameters presented in Table 3.1 have been termed an efficiency parameter by MSD because it
can be interpreted as representing the effectiveness of GI practices in reducing CSO discharge
volume for a particular CSO Region. The efficiency parameter represents the CSO volume (in
million gallons) reduced per acre of drainage area in the Region that is managed by GI facility or
acre of impervious area removed. It should be noted that the table is sorted from most efficient (or
the most responsive region for GI use) to least efficient. Refer to Figure 1-6 for the location of the
CSO Regions.
The approach developed by MSD and described in Appendix AA is conservative in two ways. First,
the approach assumes a mixed land use which is neither completely impervious nor completely grass
for the area draining to a GI facility. MSD believes that a large portion of projects completed will
take runoff from primarily impervious surfaces, and thus the net impact on CSO Volume Reduction
would be greater than predicted using the described approach. Second, the approach does not take
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advantage of the peak flow attenuation inherent in GI facilities. MSD believes that these two
unquantified aspects of CSO volume and peak flow reduction will be significant, but accounting for
them given the uncertainty in both facility type and location in the future is difficult. Because of the
uncertainty in estimating the impact of peak flow reduction on the CSO outfalls, MSD will continue
with the approach to only take credit for runoff volume reduction in GI facilities at this time. It is
anticipated that there may be an additional benefit realized of peak flow reduction that will both
provide significant additional water quality benefits and resiliency to climate change.
3.4 Evaluation of Performance Criteria and Metrics
At the completion of the Pilot, MSD has a better understanding of GI, its costs, and its capability to
reduce CSO volume. It is thus desired to revisit the initial performance metrics identified in the
CSO LTCP and used as performance criteria for the CSO control measure.
3.4.1 Total Drainage Area
Total drainage area is a primary measure for runoff volume, and thus must be considered in
quantifying available runoff to be reduced by GI practices and ultimately CSO Volume Reduction.
The methods described in Section 3.3 utilize total drainage area as the predictor for CSO Volume
Reduction within a particular CSO Region.
3.4.2 Impervious Area
Impervious area managed or removed is a significant indicator of MSD’s long term CSO GI
Program goals. While total drainage area managed is important in the calculation of runoff volume
reduced, and therefore CSO discharge volume reduced, impervious area allows comparison of
progress towards goals across the region. Because runoff processes on non-impervious surfaces
depend largely on the underlying soil conditions, it is not straightforward to compare the impact of
managing total drainage area across CSO Regions with varying soil types. The runoff processes for
impervious areas on the other hand are not dependent on location or soil type. Additionally,
impervious area is recognized as contributing large amounts of stormwater runoff to the Combined
Sewer System so that managing impervious area with GI practices will have a greater benefit of
reducing CSOs than would come from managing runoff from strictly green spaces. Therefore,
impervious area is a recommended metric and performance criteria for the CSO Green Infrastructure
Control Measure.
3.4.3 CSO Activations
CSO activations as defined in the LTCP are the number of continuous periods for which the sum of
all CSO discharges is greater than zero and separated by a minimum of 6 hours dry time. MSD
wanted to investigate its usefulness as a program metric after the Pilot study as it is an indicator of
water quality secondary to CSO discharge volume. It was found that while GI has significant
potential to reduce CSO discharge volume because of the way activation is defined and because the
number of activations is relatively insensitive to GI. It was found that even with a 20% reduction in
impervious land over the entire CSO Volume Reduction Green Infrastructure Program Area (CSO
GI Program Area), no change would be realized in number of activations. For this reason, it is not
recommended to use CSO activations as a metric in the performance criteria for the CSO GI
Program.
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3.4.4 CSO Volume Reduction
CSO volume is the primary indicator of the CSO GI Program’s long term goal. It was still
considered important after the Pilot and with the additional understanding gained, the expected range
from the LTCP is to be updated. Using the methods described in Section 3.3 of this report, it is also
possible to update the CSO volume reduction estimate as actual projects are identified and
completed in the future. MSD intends to use estimated CSO volume reduction as a performance
metric in the annual reporting for the CSO Green Infrastructure control measure.
3.5 CSO Volume Reduction for Pilot Projects
The Pilot completed by MSD included more than 176 demolitions of existing structures on parcels
which now have an established agreement to treat any future impervious surface with GI. Thirteen
of these demolition locations were temporarily used to test amended soils. In addition, the Pilot
constructed 6 Neighborhood-scale bioretention facilities, 3 Site-scale rain gardens, and 13 Site-scale
planter boxes, as described in Section 2.2.
The projects were distributed throughout the CSO Volume Reduction Green Infrastructure Pilot
Program Focus Area (Pilot Focus Area) primarily within the Rocky Branch, Salisbury and the
Biddle, and Chambers South Benton CSO Regions. An estimated total of 33 acres is considered
managed by these pilot activities. Of the 33 acres, 23.6 acres are managed through parcel deed
restrictions that limit and provide for the management of future impervious surfaces. Included in
these 23.6 acres, 9.4 acres of impervious surface was demolished within the CSO GI Program Area,
which effectively resulted in this area being changed to green. For the balance of the 33 acres, 9.5
acres of drainage area (including 5.5 acres impervious surfaces) have been controlled by being
directed into a GI facility.
Using the methods described in Section 3.3, the estimated CSO Volume Reduction for the projects
completed during the Pilot was computed. The estimate of the CSO Volume Reduction during the
LTCP typical year rainfall is approximately 4 MG, equally split between demolitions and GI
facilities. It should be noted that the demolitions volume reduction includes the soil amendment
sites and is based only on removed impervious area (9.4 acres) for net CSO volume reduction until
the entire parcel area is managed by a constructed GI practice. The planter boxes provided a
relatively small contribution to CSO Volume Reduction and were therefore not included in the
detailed calculations. The details of the calculation are presented in Table 3.2. The Drainage Area
Managed (in acres) is multiplied by the Efficiency Parameter to obtain the CSO Volume Reduction
(in million gallons).
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Project Project Location Drainage Area
Managed (Ac)
Efficiency
Parameter
(MG/Ac)
CSO Volume
Reduction (MG)
N. Vandeventer
Ave. Bioretention
Rocky Branch,
Salisbury 3.4 0.198 0.67
N. Sarah Avenue
Bioretention Central
1.37 0.32 0.44
Beacon Avenue
Bioretention Humboldt, Baden 1.79 0.182 0.33
Monroe Street
Raingarden
Biddle, Chambers
South Benton 0.05 0.126 0.01
Warne Avenue
Bioretention
Rocky Branch,
Salisbury 0.68 0.198 0.13
Clinton Street
Bioretention
Biddle, Chambers
South Benton 1.75 0.126 0.22
Monroe Street
Raingarden
Biddle, Chambers
South Benton 0.05 0.126 0.01
Geraldine Avenue
Bioretention Harlem Creek 0.42 0.186 0.08
Demolition Southern Arsenal 0.12 0.25 0.03
Demolition Central 0.84 0.32 0.27
Demolition
Rocky Branch,
Salisbury 2.74 0.198 0.54
Demolition Humboldt, Baden 1.50 0.182 0.27
Demolition Harlem Creek 2.46 0.186 0.46
Demolition
Biddle, Chambers
South Benton 0.12 0.126 0.01
Demolition Ferry 0.99 0.135 0.13
Demolition Prairie 0.61 0.129 0.08
Total 19 4
Table 3-2 Calculated CSO Volume Reduction for Pilot Projects
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4 EARLY ACTION PROGRAM
4.1 Introduction
The Early Action Program (EAP) is termed “early” because MSD is moving forward with CSO GI
Program expenditures beyond the $3 million CSO Volume Reduction Green Infrastructure Pilot
Program (Pilot) prior to approval of MSD’s full-scale implementation plan for the CSO Volume
Reduction Green Infrastructure Program (CSO GI Program). These efforts have given MSD the
ability to move forward with high priority projects and have also vastly expanded the experience
with implementation logistics, especially in the realm of partnership with other entities in
incorporating green infrastructure (GI) into their planned projects.
4.2 Early Action Program Requirements
As stated in Chapter 12 and Appendix Q, page Q-7 of the Long-Term Control Plan (LTCP), it was
agreed that the Pilot would be a five-year period with complete implementation and reporting on the
Pilot submitted to the Plaintiffs at the end of calendar year 2015. It goes on to say:
“In general, work to be done to implement the full-scale green infrastructure program will be
based on the green infrastructure plan. However, there may be projects that are identified by
MSD and can be agreed upon as being high priority projects suitable for early implementation
even before the green infrastructure plan is finalized and approved.
When MSD identifies a project or a group of similar projects that it believes is appropriate for
early implementation (i.e., to be initiated prior to finalization and approval of the green
infrastructure plan) the District will propose this project or group of similar projects as an
“early action” project(s) by submitting a written proposal to MDNR/EPA, with a copy to the
Coalition. Information shall be provided in a concise format on the design parameters, costs, and
schedule, as well as the reasons the project or group of similar projects is being proposed as an
early action project. Within 45 days, MDNR/EPA will review and either approve, tentatively
approve, tentatively disapprove, or disapprove the project(s) as an early action project(s). If
MDNR/EPA does not respond within 45 days, the proposed early action project, or group of
early action projects, is deemed approved. If MDNR/EPA tentatively approve or tentatively
disapprove a proposed early action project(s), MDNR/EPA will provide comments, questions or
other requests for information as expeditiously as possible to MSD. MSD will either respond or
may decide to drop the project as an early action project. After tentative approval or
disapproval, the process for exchanging information shall not exceed 90 days from the date of
MSD’s original submittal unless agreed to by MSD and MDNR/EPA. A final approval or
disapproval action will be taken by the end of the 90-day period. If MDNR/EPA concurs that a
project(s) is appropriate as an early action project(s), costs incurred directly related to the
project(s) will count toward the $100 million green infrastructure commitment.
4.3 Indirect Projects: Early Action Grants
While the core of the Pilot will be stormwater retrofitting conducted in partnership with the City of
St. Louis, MSD will continue to seek to build partnerships with other municipalities, schools,
community development organizations, and private developers. The goal is to engage partners to
identify joint opportunities to incorporate GI into ongoing programs and future redevelopment
projects.
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From January 2013 to January 2015, MSD submitted 28 projects to the EPA/MDNR for approval as
Early Action Grants projects. Of these projects, there are 21 projects that have been constructed or
are still active. The 21 projects will manage a drainage area of approximately 85 acres with a MSD
reimbursement amount of approximately $16.7 million. A list of the projects is provided in the
following tables and associated maps.
Metropolitan St. Louis Sewer District Green Infrastructure Program
Proposed Early Action Projects
Projects Submitted in January 2013
Project Entity Amount
Requested
Expected
Funding
Amount
Drainage
Area
Managed
(Ac)
Status
Bellefontaine
Cemetery
Improvements
Non-profit $60,000 $0 0.00 Dropped
St. Louis University
Sustainable
Improvements to
Campus
Private $45,000 $15,000 0.22 Constructed
Mississippi River
Greenway - Bellerive
Park to Sister Marie
Charles Park
Government
agency $144,718 $0 0.00 Dropped
Northside
Regeneration
Residential Phase 1
Private $900,000 $0 0.00 Dropped
North Sarah Phase II Government
agency $680,339 $680,339 3.75 Constructed
Powell Symphony
Hall Parking Lot in
Grand Center
Non-profit $750,000 $0 0.00 Dropped
CORTEX District
Green Infrastructure Non-profit $4,000,000 $5,100,000 28.60
Partially
constructed
Total $6,580,057 $5,795,339 32.57
Table 4-1 Proposed Early Action Program Projects Submitted January 2013
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Figure 4-1 Proposed Early Action Grant Projects Submitted January 2013
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Metropolitan St. Louis Sewer District Green Infrastructure Program
Proposed Early Action Projects
Projects Submitted in January 2014
Project Entity
Amount
Requested
Expected
Funding
Amount
Drainage
Area
Managed
(Ac) Status
Hyde Park Bioretention
Basins Non-profit $26,410 $0 0.00 Dropped
South Grand Pocket Park Non-profit $42,300 $42,300 0.17 Constructed
Bridge of Hope
Community Church Non-profit $110,000 $180,000 0.41 Active
Washington University
Medical Center Campus
Renewal - New East
Parking Garage
Non-profit $253,336 $253,336 3.58 Active
St. Louis Food Roof
Farm Non-profit $135,017 $135,017 0.20 Constructed
North Riverfront
Commerce Corridor
Areas 1A & 3
Government
agency $1,978,828 $1,978,828 20.00 Active
Northside Regeneration
Residential Phase 1 Private $900,000 $0 0.00 Dropped
Lafayette Square Plaza Private $205,600 $205,600 1.00 Constructed
Herbert Hoover Boys &
Girls Club Non-profit $641,688 $641,688 0.87 Active
Flance Early Childhood
Education Center Non-profit $267,937 $267,937 0.32 Active
Wells Fargo Pocket Rain
Gardens Private $205,875 $205,875 1.06 Active
The Sheldon Parking Lot Non-profit $306,682 $0 0.00 Dropped
Total $5,073,673 $3,910,581 27.61
Table 4-2 Proposed Early Action Program Projects submitted January 2014
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Figure 4-2 Proposed Early Action Grant Project Submitted January 2014
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Metropolitan St. Louis Sewer District Green Infrastructure Program
Proposed Early Action Projects
Projects Submitted in January 2015
Project Entity
Amount
Requested
Expected
Funding
Amount
Drainage
Area
Managed
(Ac) Status
Washington University
Medical Center Traffic
Improvements
Non-profit $80,082 $80,082 1.57 Active
Bellefontaine Cemetery
- Evergreen Glen
Watershed Restoration
Non-profit $82,000 $82,000 0.83 Active
Luther Ely Smith
Square Improvements Non-profit $170,190 $170,190 0.81 Active
Northside Regeneration
Residential Phase 1 Private $900,000 $900,000 8.36 Active
North Sarah Phase III Government
agency $533,564 $533,564 3.40 Active
The Nexus Green Roof Private $117,034 $117,034 0.06 Active
Sigma Aldrich
Sustainable Stormwater
Improvements
Private $890,600 $890,600 2.85 Active
Heart of Pine
Lawn/Northwoods
Point
Government
agency $2,823,700 $2,823,700 2.54 Active
Union Station
Sustainable Stormwater
Improvements
Private $1,418,000 $1,418,000 4.24 Active
Total $7,015,170 $7,015,170 24.66
Table 4-3 Proposed Early Action Program Projects submitted January 2015
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Figure 4-3 Proposed Early Action Grant Projects Submitted January 2015
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The Early Action Grants started with its first application period in August 2012. The application
instructions for Early Action Grants indirect project submittals are provided on MSD’s Project Clear
website and are as follows:
Potential Eligible Green Infrastructure Practices
The following list shows eligible GI practices. Other practices related to the GI program may be
eligible if they are in accordance with the program objectives.
Impervious area reduction
Porous pavement
Reinforced turf
Amended soils
Planter boxes
Bioretention/Rain gardens
Impervious area sheet flow to buffer
Rooftop disconnection to rain barrel
Rooftop disconnection to cistern: irrigation reuse
Rooftop disconnection (splash to grade)
Green roofs
Blue roofs
Green streets
Curb extensions/Street bump outs
Educational Signage for Green Infrastructure
Other techniques as approved by MSD
Eligible Recipients
The following entities are eligible for financial partnering:
Municipalities and local government agencies
Schools
Non-profit organizations
Community development organizations
Business owners
Private developers
Funding Considerations
The Early Action Grants is a reimbursement program. Grantees must have adequate funding
available to cover all aspects of their GI project. MSD construction approval of the GI facility,
including stabilization of the tributary area upstream of the GI facility, is required prior to
reimbursement. MSD plans to spend approximately $5 million per year on the CSO GI Program,
which will fund both MSD projects and Early Action Grants. Allocations will be based on a priority
ranking system. Projects that provide a funding match will receive a higher priority ranking but
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providing a funding match is not required. Costs that may be eligible for reimbursement by MSD
include the following:
Engineering
Soils assessment and/or restoration
Legal costs associated with deed restrictions and/or easements
Property acquisition
Demolition
Construction of GI
Public participation activities
Monitoring of GI and associated laboratory analyses.
Costs for maintenance of GI facilities are not eligible. Projects that are completed or have already
started construction are not eligible.
Required Activities
Preference shall be given to projects that can manage at least 1.14 inches of stormwater rainfall from
the contributing drainage area. A reduction of runoff volume must be demonstrated and supported
with calculations. Applicants should utilize the Maximum Extent Practicable (MEP) spreadsheet
and calculation tool available at MSD’s website at stlmsd.com/what-we-do/stormwater-
management/bmp-toolbox/calculation–and-report-preparation-tools.
Upon approval, all projects chosen for financial assistance shall be submitted for review per the
District’s development review process. The cost categories listed above plus maintenance cost for
GI (during the first five years of operation) must be tracked and reported.
Evaluation Criteria and Process
General
Evaluators from MSD will score projects based on the application information submitted by the
applicants. Project ranking will be primarily based on their potential for anticipated reduction of
Combined Sewer Overflow (CSO) overflow volume. Eligible projects must be located upstream of a
CSO outfall that discharges directly to the Mississippi River. Projects that are located downstream
of the low flow interceptor will not be eligible. Wherever opportunities exist for MSD to make
informed choices between different properties available for stormwater retrofitting with GI, MSD
will prioritize these projects based on their expected CSO reductions from previous hydrologic
modeling.
For example, properties in the Harlem, Baden, and Rocky Branch citysheds would receive a higher
ranking than those in the Mill Creek cityshed because of the greater response rate of CSOs to
changing imperviousness in the former three citysheds. In addition, certain areas within the CSO
Volume Reduction Green Infrastructure Program Area (CSO GI Program Area) may be a lower
priority due to GI funding from previous years of this program that is already committed to those
areas. Efforts to coordinate with City of St. Louis Planning will also be considered, based on
focused areas of redevelopment to partner with other funding sources such as community
redevelopment fund areas. The project needs to be planned well enough to be constructed within the
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grant cycle, and, as mentioned above, must have funding to build the project with reimbursement by
MSD after the construction has been completed and approved.
Project Specific
Benefit points will be awarded for each 100 cubic feet of runoff volume reduced and each 100
square feet of impervious area removed or redirected to a Best Management Practice (BMP).
Projects proposed by municipalities and local governmental agencies will receive more benefit
points than non-profit entity projects, which will receive more benefit points than private entity
projects.
Additional benefit points may be awarded for proposed activities such as: public education,
information, and communication; innovative GI technologies; stormwater monitoring and analysis
program; location of CSO; project visibility; feasibility of future expansion; maintenance capability;
long term sustainability; and environmental justice considerations. The total benefit points will be
divided by MSD’s cost (in thousands of dollars) to calculate the priority ranking. This will yield the
most benefit points per MSD dollar spent.
Award of Funds
MSD will award funds through a CSO Green Infrastructure Grant Program Agreement executed by
MSD and the Grantee. The Agreement will describe the project, specify the funding amount and
outline additional terms and conditions, and will serve as the legal commitment of both parties as to
the scope and quality of work and the amount of funds committed. A BMP Expense Form, listing
the amount of reimbursement for each BMP, will be attached to the Agreement. The BMP Expense
Form must be completed prior to execution of the Agreement.
Disbursement of Funds and Progress Reports
Funds will be disbursed on a cost-incurred basis and supported with original receipts verifying costs.
MSD construction approval of the GI facility, including stabilization of the tributary area upstream
of the GI facility, is required prior to reimbursement. Progress reports are due with each payment
request. Progress reports are required each month regardless of the level of work completed during
the period unless otherwise specified by the District. Progress reports are required for timely
processing of payment requests.
Application and Submittal Process
The application period started in August 2012 for potential projects in MSD’s Fiscal Year 2013 (July
1, 2012 to June 30, 2013). The application period is from August 1 to October 31 of the current
fiscal year for projects to be selected for construction commencement in the following fiscal year.
An example is as follows:
FY 2014 Submittals
o The application period is from August 1, 2013 to October 31, 2013.
o Applications are due to MSD by October 31, 2013 at 5:00 p.m.
o MSD will notify the applicants of their decision by March 1, 2014.
o Construction must begin prior to September 1, 2014 (Fiscal Year 2015 begins July 1, 2015
and ends June 30, 2015).
A fourth round of applications has been added for August 1, 2015 to October 30, 2015.
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A copy of the Early Action Grants application form, the Benefit Allocation Schedule used for
ranking Early Action Grant applications, the MSD Green Infrastructure Grant Program Agreement
executed by MSD and the Grantee, and BMP Expense Form used for requesting reimbursement are
included in Appendix BB. The awarded applicant is also responsible for reporting maintenance
activities and costs on an annual basis to MSD.
The final group of Early Action Grants projects is concentrated on opportunities with upcoming
redevelopment within the GI Program Area. The “CSO Early Action Projects Grant Program” is a
reimbursement program where an entity such as a municipality, school, community development
organization, or private developer wishes to incorporate GI components into their new development.
MSD generally allocates $5 million per fiscal year to this program for both indirect and direct
projects. An application and priority ranking process was developed in order to prioritize those
projects for proposal to EPA.
Inspections and Maintenance
Each project owner is required to sign a Maintenance Agreement and is provided with instructions
on maintenance guidelines. MSD’s Environmental Compliance staff inspects the BMP once every
three years and documents their findings in the “Stormwater Management Facility Maintenance
Inspection Checklist” form (the same form utilized for Neighborhood-scale projects).
4.4 Direct Projects: MSD Acquired Neighborhood-scale Facilities
MSD’s success in the design and implementation of the Pilot encouraged MSD to submit to EPA an
additional 6 MSD-acquired Neighborhood-scale facilities as EAP projects. These projects are
identified in the table below. The project areas were selected from the remainder of the acceptable
sites from MSD’s site selection effort under the Pilot. At this point, no further acceptable sites have
been identified for implementation in the full-scale CSO GI Program. At the time of writing this
report, all the direct EAP projects have been designed and are either complete or under construction.
The approach, implementation, and results are identical to the Pilot and therefore, will not be
repeated here in the EAP discussion of lessons learned.
PUBLIC NAME Planted Address Zip
code
Blair Ave. Rain Garden in Hyde Park Spring, 2015 3961 Blair Av. 63107
19th St. Rain Garden in Hyde Park Spring, 2015 3301 19th St. 63107
Linton Ave. Rain Garden in Fairground Fall, 2015 4318-4320 Linton Av. 63107
Prairie Ave. Rain Garden in Fairground Fall, 2015 4229-4231 Prairie Av. 63107
N. Spring Rain Garden in JeffVanderLou Fall, 2015 2723 N. Spring Av. 63113
Lee Ave. Rain Garden in O'Fallon Fall, 2015 4212-4216 Lee Av. 63115
Table 4-4 Early Action Neighborhood-scale Facilities
4.5 Education and Outreach: Rainscaping Small Grants Program
The Pilot and Early Action Grants generated a lot of inquiries by the general public for installing
CSO GI on their individual properties. These small projects did not warrant the level of design and
rigorous paperwork required for the Early Action Grants. Therefore, MSD proposed to EPA in 2013
to spend $250,000 under the EAP and to develop a “Rainscaping Small Grants” program within the
CSO GI Program Area, primarily for the purpose of education and outreach. The term
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“Rainscaping” was developed by MSD’s Public Information Office as another name for GI so that
the public would be able to visualize the effect of GI on the landscape. Grants up to $3000 were
made available during a “model” round with area churches and schools to help work out the logistics
and promote the Rainscaping Small Grants program, and then a full round was conducted in the
spring of 2015.
The Rainscaping Small Grants Program encourages the use of simple GI techniques, i.e.
“rainscaping” on individual properties within the CSO GI Program Area. This “Rainscaping Small
Grant Program” targets individual landowners for the primary purpose of education. A Model
Round of the program was kicked off in August, 2014. A Full Round of grants was conducted in
2015. Since the focus of this program is on education and voluntary actions by individual residents,
MSD’s tracking of performance and CSO reductions for these facilities will not be included in CSO
performance measurements, although an unquantified benefit will certainly occur from the program.
The main objective for the Rainscaping Small Grants Program is to encourage the use of simple
rainscaping techniques by individual landowners to build capacity for community acceptance. In
addition, this program will help educate the public to understand how stormwater impacts the
combined sewer system and how the community can be part of the solution through the use of
rainscaping techniques on their properties. Rainscaping techniques such as rain barrels, rain
gardens, bioretention cells, lawn amendments, and amended soils, among others, are eligible for
grants of up to $3,000 per project. To assist MSD with administrating the grant program, MSD has
made an agreement with the Missouri Botanical Garden (MBG), a local entity that conducts a similar
grant program in the Deer Creek Watershed in St. Louis County.
Since the Rainscaping Small Grants Program focus is education, applicants are required to attend an
orientation meeting in order to be considered for a grant. The orientation covers information about
stormwater issues and the combined sewer system as well as discussing the grant process, going
through application forms, and covering some basics of design. Applicants are encouraged to use a
“participating contractor” to assist with design and/or installation of the GI features. Participating
contractors apply to the program and are required to attend an orientation. MSD and MBG provide a
list of Participating Contractors but do not certify the technical expertise of contractors participating
in the program. Applicants are encouraged to get bids and discuss qualifications with multiple
contractors.
In order to encourage participation which will maximize the education and outreach benefits of the
Rainscaping Small Grants Program, the grantees agree to maintain their features. However, there is
no formal maintenance agreement such as those recorded for GI features intended to meet
stormwater management requirements (as was required for the planter boxes in JeffVanderLou or the
raingardens on Monroe). While we expect to get some CSO volume reduction from the Rainscaping
Small Grant features, we are not including them in our volume reduction calculations at this time.
A committee with representatives from MSD, MBG, Metropolitan Congregations United, and the
Missouri Coalition for the Environment worked to develop the Rainscaping Small Grants Program.
The committee decided that for the 2014 Model Round, community-based locations such as
churches and schools would be optimal model sites. These sites offer an opportunity to engage
captive audiences that could learn about rainscaping features when they visit these locations.
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The goal is that the Model Round will help provide education and outreach to engage the public for
the program’s Full Round starting in February 2015. MSD also provided signs for the grant sites,
handouts, and other promotional materials to encourage property owners to participate in the Full
Round. The Rainscaping Small Grants program includes landowner workshops, participating
contractors to help with design and installation, and a hotline phone number and email address to
promptly answer questions throughout the process and during the following year for maintenance
questions.
MSD partnered with the MBG to help administrate the Model Round. Eight applications were
received from five different community locations for a variety of rainscaping projects. Locations of
these recipients include:
Clay Elementary School
Soulard Co-op Garden
St. Elizabeth Mother of John the Baptist Church
St. Matthew the Apostle Church
Clyde C. Miller Career Academy
A detailed description of the
Rainscaping Small Grants Program
including the Background, Program
Guidelines, and an Application are
shown in Appendix CC.
The interest in the second round
increased dramatically with the
District receiving 66 applications.
Fifty-one (51) of those entities are
receiving grants for a total of
$134,831.66 based on their requests.
In fact, there was a waiting list of 7
applicants in case any recipients
decided to opt out. Per the
Agreement, construction of these
projects had to be completed by
October 2015 in order to be
reimbursed. A listing of recipients
for the Model Round and the Full
Round are shown in Appendix CC.
Figure 4-4 Soulard Co-op Garden – Lawn Alternative
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Figure 4-5 St. Matthew the Apostle Church - Rain Garden
Figure 4-6 St. Elizabeth Mother of John the Baptist Church - Rain Barrels
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Figure 4-7 Clyde C. Miller Career Academy – Rain Garden
4.6 Findings and Results
4.6.1 Project Summary
As part of MSD Project Clear, the Consent Decree (CD) and the LTCP provides for early
implementation of high priority projects before the CSO Volume Reduction Green Infrastructure
Plan is finalized and approved by the EPA. EAP is MSD’s program for identifying and submitting
for approval projects for early implementation. While the core of the Pilot was focused on
stormwater retrofitting in partnership with the City of St. Louis, MSD endeavored to seek
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opportunities to build partnerships with other municipalities, schools, community development
organizations, and private developers within the CSO GI Program Area. These partnerships provide
an opportunity to incorporate GI into ongoing programs and future redevelopment projects. One of
the main challenges to encouraging implementation of GI on privately owned land stems from
funding and financing barriers (Brown, 2014). To help private land owners overcome this barrier
and to encourage partnerships and GI practices, MSD implemented the Early Action Grants.
The Early Action Grants specified GI elements that were eligible for funding, which included
impervious area reduction, pervious pavement, reinforced turf, planter boxes, amended soils,
bioretention/rain gardens, impervious area sheet flow to buffer, rooftop disconnection to rain
barrel/cistern/splash to grade, green roofs, blue roofs, green streets, curb extensions/street bumpouts,
educational signage for GI, and other techniques as approved by MSD. The Early Action Grants
reimbursed accepted applicants for approved GI elements of the projects submitted to MSD. With
the first round of applications accepted in 2012, MSD announced the third round of a GI program
cost-sharing opportunity in 2014. A fourth round of applications was accepted in 2015.
Seven projects were submitted to MSD in January 2013, of which four were delayed or dropped by
the owner’s request or for not meeting Early Action Grants schedule requirements. Twelve projects
were submitted in January 2014 and three of the projects were delayed or dropped by the owner’s
request. Nine projects were submitted in January 2015, all of which are still active and pending
construction.
The Early Action Grants has set a framework for opportunities to build partnerships and incorporate
GI in future development/redevelopment projects. Moving forward, consideration to application
review time required, modifications to time frame for application receipt, and construction start time
will be reviewed to enhance the continuation of a Green Infrastructure Grants Program as part of the
full-scale implementation of the CSO GI Program.
The total anticipated reimbursable funding for projects submitted from 2013 to 2015 for all active
projects in the program is $18,748,090. As of June 2015, MSD Development Review has provided
plan approval for 13 projects with total construction costs of $6,300,873. Total MSD approved
reimbursable construction costs is $4,778,663, based on reimbursing only eligible GI costs. Of these
approved projects, GI practices incorporated include bioretention/rain gardens, pervious pavement,
enhanced street trees (i.e. Silva Cells), green roof, amended soils, rainwater harvesting (cisterns), and
bioswales.
The Early Action Grants projects that have received MSD plan approval by the Development
Review group to date are listed below in Table 4.5.
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Table 4-5 List of Early Action Green Infrastructure BMP Technologies Receiving MSD Plan Approval as of June 2015
EARLY ACTION GI FACILITY NAMEPROJECT NUMBERBMP TYPETotal Drainage Area (SF)Design Impervious Area (SF)Total Construction CostTotal MSD Costs (MSD Approved Reimbursement Amount)St. Louis University Sustainable Improvements to Campus (SW of the Busch Student Center)P-0029866-00 Bioretention (2)9540 2178 15,000.00$ 15,000.00$ North Sarah Phase IIP-0029426-01Permeable Pavement (Concrete)and French Drain163350 99753 1,530,930.00$ 581,769.00$ North Sarah Phase IIP-0029426-02 Bump Out Rain Gardens (11) *49223 133,777.00$ 50,857.00$ North Sarah Phase IIP-0029426-02 Rain Garden (2)*4791 35,400.00$ 13,456.00$ CORTEX District Green Infrastructure Phase IP-0029761-00 Bioretention (25)226076 156836 2,399,826.37$ 2,271,276.36$ CORTEX District Green Infrastructure Phase I P-0029761-00Permeable Pavement (Permeable Paver Blocks)12197 12197 118,909.22$ 118,909.22$ CORTEX District Green Infrastructure Phase IP-0029761-00 Silva Cells (2)18731 18731 262,793.58$ 251,043.58$ CORTEX District Green Infrastructure Phase I P-0029761-00Bioretention w/Silva Cells (2)15246 24234 188,410.71$ 188,410.71$ Washington University Medical Center Campus Renewal - New East Parking GarageP-0011704-03 Bioretention (7) 195584 156129 292,550.00$ 253,336.00$ St. Louis Food Roof Farm P-0030155-00 Agricultural Green Roof 8927 8927 356,117.00$ 135,017.00$ Fountain Park Plaza P-0025970-01 Bioretention 33910 27300 124,917.00$ 58,300.00$ Fountain Park Plaza P-0025970-01Permeable Pavement (Concrete & Pavers)9530 5990 147,300.00$ 147,300.00$ South Grand Pocket Park P-0029755-01 Amended & Structural Soils 7405 535 43,254.00$ 42,300.00$ Bridge of Hope Community Church P-0030323-00 Cistern 3940 3940 52,525.00$ 52,525.00$ Bridge of Hope Community Church P-0030323-00 Bioswale 9685 8255 36,120.00$ 36,120.00$ Bridge of Hope Community Church P-0030323-00 Bioretention 4260 15585 91,355.00$ 91,355.00$ Wells Fargo Advisors Corporate Campus BioretentionP-0030192-00 Bioretention (39) 52727 46277 205,500.00$ 205,500.00$ Flance Early Childhood Education Center P-0029337-01 Bioretention (2) 10640 8777 107,668.00$ 107,668.00$ Flance Early Childhood Education Center P-0029337-01 Dry Swale 4287 450 92,539.00$ 92,539.00$ Flance Early Childhood Education Center P-0029337-01 Cisterns (2) 4680 4680 65,981.00$ 65,981.00$ TOTAL:$6,300,872.88 4,778,662.87$
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4.6.2 Early Action Grants Lessons
The Early Action Grants program was a very effective method to implement GI during the Pilot.
The benefits of the program include:
A significant amount of community excitement and positive press was received from the
program about the successful implementation of some of the projects, which improves the
public’s perception of GI and its benefits.
The program was a means to develop meaningful and beneficial partnerships with various
organizations in the community.
The program experienced a great deal more variety in the application of various GI
technologies (i.e. green roofs and silva cells) into a variety of urban settings (i.e. building
roofs, universities, parks and commercial areas).
Generally, these facilities directly and immediately helped to promote economic vitality in
the City of St. Louis by being associated with new development.
The design and construction of the Early Action Grants projects was typical of MSD’s plan
review and construction inspection for stormwater BMPs since 2006 and therefore, this
aspect of program implementation was fairly routine.
Alternatively, a number of negative aspects of administering the program were realized, which will
be addressed in the full scale implementation of the CSO GI Program:
A significant number of selected requestors dropped out of the program due to various
reasons, the most notable was the project was not ready for construction within the grant
cycle (6 months from initiation of Agreement).
A significant amount of time and discussion was spent by MSD personnel and others to
determine reimbursable expenses, review monthly progress reports, invoices, and BMP
expense forms. This aspect added to the delays and work load of the projects, both internally
and for the customers.
4.6.3 Early Action Program Expenditures
Once approved plans are constructed, eligible costs are submitted to MSD for reimbursement. The
status of the CSO GI Program costs from actual reimbursements paid to applicants for Early Action
Grants projects as of September 2015 are as follows:
Project Project Number
Costs
Amount
Requested
Plan Approval
Amount
Amount
Reimbursed
To Date
North Sarah Phase II P-29426-00, 01,
& 02 $680,339.00 $680,339.00 $647,264.00
St. Louis University
Sustainable
Improvements to
Campus
P-29866-00 $45,000.00 $15,000.00 $14,989.17
South Grand Pocket
Park P-29755-01 $42,300.00 $42,300.00 $42,300.00
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Bridge of Hope
Community Church P-30323 $180,000.00 $180,000.00 $33,973.00
St. Louis Food Roof
Farm P-30155 $135,017.00 $135,017.00 $135,017.00
TOTAL: $873,543.17
4.6.4 Predicted CSO Volume Reduction
Using the methods described in Section 3.3, Hydraulic and Hydrologic Modeling, an estimate of the
CSO Volume Reduction was computed for the EAP Projects. The estimated reduction for the MSD
acquired, Neighborhood-scale EAP projects is 1.6 MG and presented in Table 4.7.
Project Project Location Drainage Area
Managed (Ac)
Efficiency
Parameter
(MG/Ac)
CSO Volume Reduction
(MG)
Blair Ave. Rain
Garden in Hyde
Park
Ferry 0.9 0.135 0.12
19th St. Rain
Garden in Hyde
Park
Rocky Branch,
Salisbury 0.3 0.198 0.06
Linton Ave. Rain
Garden in
Fairground
Prairie 1.36 0.129 0.18
Prairie Ave. Rain
Garden in
Fairground
Ferry 1.48 0.135 0.20
N. Spring Rain
Garden in
JeffVanderLou
Rocky Branch,
Salisbury 3.93 0.198 0.78
Lee Ave. Rain
Garden in O'Fallon
Rocky Branch,
Salisbury 1.24 0.198 0.25
Total 9.2 1.6
Table 4-7 Calculated CSO Volume Reduction for MSD Owned EAP
The estimated CSO Volume Reduction for fully completed and reported Early Action Grants EAP
projects not owned by MSD is 1.4 MG and presented in Table 4.8.
Project Project
Location
Drainage Area
Managed (Ac)
Efficiency
Parameter
(MG/Ac)
CSO Volume Reduction
(MG)
North Sarah Phase II Central 3.75 0.32 1.20
St. Louis University
Sustainable
Improvements to
Campus
Central 0.22 0.32 0.07
Table 4-6 Early Action Projects - CY 2014 Expenditures and CY 2015 (through 9/17/15) Expenditures
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South Grand Pocket
Park
Southern
Arsenal 0.17 0.25 0.04
Bridge of Hope
Community Church
Rocky Branch,
Salisbury 0.41 0.198 0.08
St. Louis Food Roof
Farm
Biddle,
Chambers South
Benton
0.2 0.126 0.03
Total 4.7 1.4
Table 4-8 Calculated CSO Volume Reduction for EAP Owned by Others
4.6.5 Conclusions
The implementation of the EAP portion of the CSO GI Program was very positive and resulted in a
total to date of 13.9 acres managed, thereby reducing CSOs by 3 MG annually. In addition, the
projects in construction promise to reduce significantly more CSO volume. There were fewer
lessons learned due to the routine nature of the work through the Development Review, Permitting,
Construction Inspection, and BMP maintenance enforcement functions that MSD performs on a
daily basis. However, the Early Action Grants projects developed further partnerships with other
entities in addition to the Land Reutilization Authority (LRA). Also, the application process
provided a basis for ranking and prioritizing projects, and in some cases afforded the opportunity for
MSD to take advantage of matching funds provided by the applicant for the GI costs. MSD plans for
this aspect of the program to play to continue a prominent role in the future.
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5 GREEN INFRASTRUCTURE PROGRAM FULL IMPLEMENTATION PLAN
5.1 Introduction
The CSO Volume Reduction Green Infrastructure Program (CSO GI Program) plan as described in
this section will provide guidance to MSD in implementing green infrastructure (GI) with the focus
of reducing Combined Sewer Overflow (CSO) discharge volume to the Mississippi River during the
LTCP typical year through runoff volume reduction. The Green Infrastructure Plan (GI Plan) will
describe how the remainder of the $100 million for the full-scale implementation of the CSO GI
Program will be spent. The GI Plan period begins upon approval of the plan, early in 2016, and will
be complete by June 30, 2034. Including the $3 million used to fund the CSO Volume Reduction
Green Infrastructure Pilot Program (Pilot), MSD has committed to spend a total of $100 million on
GI under the CSO GI Program.
Over time, it is expected that conditions may change or new information may lead to the need to
make changes in the CSO GI Program Plan, such as major infrastructure projects not currently
identified or less than anticipated participation in GI grant programs. In order to adjust to changing
circumstances and to incorporate a variety of lessons learned through GI implementation, an
adaptive management approach to the CSO Green Infrastructure Program Plan is proposed.
5.2 CSO Green Infrastructure Program Requirements
MSD’s CSO GI Program was identified as part of the Consent Decree (CD) in the Combined Sewer
Overflow Long-Term Control Plan (CSO LTCP) as the selected CSO Control Measure for outfalls
discharging to the Mississippi River. The CSO LTCP specifies that upon completion of the Pilot,
MSD will submit, in this final report, “A plan, based on the results of the pilot program, for the full-
scale implementation of the $100 million green infrastructure program, including reporting of
progress in the annual progress reports…” (LTCP, p. Q-6). MSD’s GI Plan for full-scale
implementation of the CSO GI Program is outlined in Sections 5 and 6 of this report.
In additional to outlining the full-scaled implementation plan, this section will also identify the
“Performance Criteria” against which progress toward the CSO GI Program CSO Control Measure
will be reported in the annual progress reports (CD, Appendix D).
5.3 Selection of Green Infrastructure Types and Program Components
Types of GI practices and CSO GI Program components selected for the full-scale implementation
plan are based on experiences gained from the Pilot and Early Action Program (EAP).
5.3.1 Evaluation of Effectiveness, Implementability, and Costs
Effectiveness, lessons learned related to implementability, and GI costs all contribute to the selection
of final project types and program requirements of this final plan.
5.3.1.1 Effectiveness
Monitoring result performance was discussed in Section 2.15. The bioretention and porous alleys
performed better than expected and are considered desirable technologies for CSO volume reduction.
Conclusions regarding soil amendments and planter boxes were not as definitive. Based on the
results of monitoring during the Pilot, plus MSD’s experience in regulating stormwater Best
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Management Practices (BMPs) in the Municipal Separate Storm Sewer System (MS4) area, MSD
anticipates the most success and popularity by using bioretention-related facilities followed by
porous pavement.
5.3.1.2 Implementability
Implementability lessons were gained through both the Pilot and EAP, with key lessons regarding GI
practices and program features highlighted here.
Neighborhood-scale vs. Site-scale Facilities
In the implementation of the full CSO GI Program, MSD will emphasize Neighborhood-scale
facilities over Site-scale facilities. The concerns of individual homeowners required to maintain site-
scale facilities and MSD being required to enforce maintenance is simply not desirable. A great deal
of effort was spent educating the owners about the facility and although the results were positive in
some aspects, the negatives outweighed the positives. MSD observed a lack of interest in proper
maintenance of the rain gardens and even received complaints related to safety concerns with the
planter boxes. Therefore, to ensure long term maintenance of the facilities, MSD will focus efforts
on Neighborhood-scale practices in general.
Direct Projects vs. Indirect Projects
Direct Projects are those implemented by MSD staff and/or consultants on real estate obtained and
owned by MSD. The Indirect Projects are those managed and constructed by a third-party on
property not owned by MSD. After implementation of the Pilot and EAP projects to date, MSD
continues to believe that the delivery of GI will better serve the St. Louis community through
Indirect Projects.
To repeat Appendix Q of the LTCP, “Actual redevelopment opportunities will play a significant role
in the decision making process.” MSD has not observed the Direct Projects as being a quick
solution to the environmental, social and economic needs of the City of St. Louis, and continues to
believe that “building green infrastructure now, to accommodate runoff that may not exist for several
years, can and should be deferred until closer to the actual redevelopment occurring.” Therefore,
MSD will attempt to revise the Early Action Grants application process to better improve
participation.
Depending on market conditions for development or redevelopment, Direct Projects may still be
needed in order to meet CSO GI Program goals for spending the $100 million before the critical
milestone date in the CD. MSD will continue to pursue locations for placement of Direct Projects.
With MSD’s current ownership of property very low and past efforts at identifying practical sites not
very productive, the potential for significant delivery of GI using this method is likely limited. Thus,
both Direct and Indirect delivery will be pursued, with the initial emphasis on Indirect Projects.
5.3.1.3 Costs
Project costs associated with GI practices used for CSO volume reduction is an important factor for
selecting GI practices for the CSO GI Program. In addition to GI effectiveness and lessons learned
related to implementability, costs are an important factor for project and GI practice selection.
Table 5.1 summarizes costs by project type and/or by GI practice. Costs incurred for maintenance
are not provided. Costs provided include costs incurred by MSD and not by the private property
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owner. It should be noted that projects completed under the Rainscaping Small Grants Program are
not counted towards CSO volume reduction.
Project Type
Impervious
Area
Redirected
Total
Drainage
Area
Controlled
Total
Costs
Low
Cost/Acre
of Drainage
Area
Controlled
High
Cost/Acre
of
Drainage
Area
Controlled
Average
Cost/Acre
of Drainage
Area
Controlled
(Acres) (Acres) ($) ($) ($) ($)
MSD PILOT PROJECTS
Neighborhood-Scale
Bioretention 5.53 9.51 $1,250,614 $ 58,235 $386,157 $ 188,138
LRA Properties -
Building Demolitions* 9.4 -- $1,365,572 -- -- $ 145,894
Amended Soils N/A 0.93 $ 24,700 $ 16,086 $ 44,942 $ 26,759
Site Scale Rain Gardens 0.08 0.12 $ 12,600 $ 68,032 $155,471 $ 107,544
Site Scale Planter Boxes 0.38 0.38 $ 39,000 $ 102,631 $102,631 $ 102,631
MSD EARLY ACTION PROGRAM PROJECTS
Early Action Projects
(Total) 15.03 18.20 $4,778,663 $ 56,422 $ 658,826 $ 306,326
MSD SMALL GRANT RAINSCAPING PROGRAM PROJECTS
Rainscaping Small Grant
Program Projects (All) -- -- $ 134,832 -- -- --
*Numbers in this table only reflect the MSD funded demolitions inside of the CSO GI Program Area
Table 5-1 Summary of MSD Costs for Pilot Program Green Infrastructure Projects
It should be noted that engineering, education, outreach, and internal labor are not included in the
costs for the building demolitions, amended soils or the site–scale projects. While engineering costs
are included in the Neighborhood-scale projects, costs related to site-selection, property acquisition
or demolitions on the lots are not included on the table.
EAP projects incorporated the following GI practices: bioretention/rain gardens, pervious concrete,
permeable pavers, silva cells, green roof, bioswales, cisterns, and soil amendments. Rainscaping
Small Grant Program projects incorporated the following GI practices: lawn alternatives, rain
barrels, woodland restoration, green roofs, permeable pavers, bioretention/rain gardens, filter socks,
and bioswales. Costs for the six MSD bioretention funded as an “Early Action” projects are not
included; two of these projects are completed with the remaining four not yet completed.
Comparing the public-private partnership projects (Early Action Grants projects) and Pilot projects
(Site-scale and Neighborhood-scale), cost for public-private partnership projects are considerably
more costly per acre controlled. The cost per CSO volume removed is greater for the public/private
partnerships than the MSD Site-scale projects, and the MSD Neighborhood-scale bioretention
projects. However, as noted above, the Pilot cost summary excludes some of the costs inherent in
the EAP projects, such as demolition. Amended soils were the least costly GI practices when
considering average cost per acre of drainage area controlled. Of the Pilot projects, the
Neighborhood-scale projects resulted in the highest average cost per acre of drainage area controlled.
Also note the significant variance in cost from the lowest to highest cost per acre controlled.
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Reviewing these costs and the various facilities they represent, MSD has determined a reasonable
cost estimate for future GI will be $200,000 to $250,000 per acre.
MSD’s Early Action Grants set a framework for opportunities to build public-private partnerships
for the incorporation of GI in future private development/redevelopment projects. While the cost of
the public-private partnership projects is found to be higher than the MSD Pilot projects, these
projects are still deemed to be a preferred and valuable option for investing in GI.
It is anticipated that future MSD-owned GI projects will likely be in the vicinity of the Harlem and
Baden CSO regions, where vacant lots and abandoned properties are available. These CSO regions
are not considered to be the “best bang for the buck” as they result in a lower CSO volume reduction
compared to the Central CSO region. The Central CSO region is where the majority of private
development is occurring and this area also yields a higher percent CSO volume reduction. Being
completed in conjunction with development, MSD believes this can increase the longevity of the GI
as it will have higher visibility as part of the development’s landscape. Investing in GI where
development is occurring is in line with the triple bottom line of sustainability and GI. The private-
public partnerships allow MSD to take advantage of current opportunities and provides for the social
and economic needs of the community.
Due to the lack of property that is MSD-owned, it is anticipated that most GI installed will be
constructed on property not owned by MSD as Indirect Projects. However, to determine if any
opportunities for purchasing land feasible for GI projects exist, MSD will review LRA-properties for
potential to identify future direct projects.
5.3.2 Types of Green Infrastructure Practices
As MSD planned for development of the CSO GI Program, several GI practices were considered and
evaluated. Several commonly used GI practices were used in the Pilot and EAP resulting in valuable
lessons learned on how and if the practice should be included in the full implementation program. In
addition to those commonly used GI practices, other “green” practices emerged as potential practices
to implement in the full CSO GI Program for additional CSO volume reduction. Table 5.2 revisits
the commonly used GI practices, also presented in Section 2.6 of this report, and introduces the other
green practices considered.
The intent of the table is to summarize practices implemented as part of the Pilot, the EAP and other
green practices, and to summarize MSD’s evaluation of the applicability of each practice to the full
CSO GI Program Plan implementation as a stand-alone practice. When evaluating each practice for
applicability to the full CSO GI Program, consideration was given to feasibility, significance to
volume reduction, construction costs, maintenance needs, acceptability, and benefits to the
community. An explanation of the rankings for each practice is provided in the table. The delivery
mechanism, Indirect or Direct, and the scale, Neighborhood or Site, is also indicated for the practice
as determined to be best fit for the respective practice moving forward. For implementation of GI,
the delivery mechanism and project scale are important factors as they impact project costs, the long-
term maintenance needs, and the acceptability of the GI for implementation.
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Green
Infrastructure
Practice
Description
Included in GI
Program to Date
Delivery
Mechanism Scale Applicability to Full
Implementation Plan as a
Stand-alone Practice Pilot Early
Action Direct Indirect Neigh-
borhood Site
Amended Soils
Soil amendments are any materials,
organic or inorganic, that are added
to a soil. Soil amendments increase a
soil's infiltration and water retention
capacity and add runoff storage
volume.
X X X X
Low – Not best used as a
stand-alone practice and it is
hard to quantify volume
reduction benefit
Bioretention /
Rain Garden
Bioretention basins, commonly
referred to as rain gardens, are
shallow surface depressions planted
with specially selected native
vegetation to treat and capture runoff.
X X X X X X
High – Commonly used as an
effective stand-alone water
quality and volume reducing
green practice
Bioswales
Bioswales are shallow stormwater
channels planted with a variety of
grasses, shrubs, and/or trees to slow,
filter, and infiltrate stormwater
runoff.
X X X X X
High – Commonly used as an
effective stand-alone water
quality and volume reducing
green practice
Downspout
Disconnections
Downspout disconnection is the
process of separating roof
downspouts from the sewer system
and redirecting roof runoff onto
pervious surfaces, such as a lawn or
rain garden. This gives the roof
runoff the opportunity to infiltrate,
reducing the volume of runoff to the
sewer system.
X X X X
Low – Not best used as a
stand-alone practice, typically
incorporated with other
methods.
Green Roofs
Green roofs, also known as vegetated
roofs, are vegetated systems placed
on roof surfaces that capture and
store rainwater in soil medium.
X X X X
Medium – High cost but
popular, good as indirect
project limited to commercial.
Infiltration
Trench
Infiltration trenches are subsurface
infiltration structures composed of a
stone trench used for stormwater
infiltration and conveyance in
drainage areas.
X
Low – St. Louis area does not
have rapidly infiltrating soils,
and the number of new
developments with this
practice is relatively low.
Pervious
Pavement
Pervious pavement combines
stormwater infiltration, storage, and
structural pavement consisting of a
permeable surface underlain by a
storage/infiltration bed
X X X X X X
Medium – High cost but used
often for indirect projects,
maintenance and durability
concerns. Does not result in
the loss of usable space.
Planter Boxes
Planter boxes are containers or
enclosed structures located at least
partially above ground and planted
with vegetation that captures, filters
through soil media, and may infiltrate
or slowly release stormwater runoff.
X X X
Medium – Cost effective,
ensuring maintenance required
a lot of effort on individual lot
owners.
Rainwater
Harvesting
Rainwater harvesting using cisterns
and rain barrels are storage
containers designed to intercept and
store runoff from rooftops and other
impervious surfaces to allow for its
reuse.
X X X
Low – High cost and requires
active management. Could be
used for large indirect projects
depending on plan to use
water. MSD’s individual rain
barrel sales program was
canceled as participation
waned.
Tree Boxes
Tree boxes incorporate stone storage
areas, in combination with planting
soils for healthy tree growth,
providing storage for captured runoff
to infiltrate into the soil. They can be
used in ROWs of streets and in
public space such as plazas and
parks.
X X X
Medium – High cost for this
practice yield it not as cost
effective as others
Other GI
Practices
Considered
Demolition
Demolitions of buildings reduce
impervious surfaces that generate
storm water runoff that contributes to
CSO discharge volume.
X X X X X X
High - Can yield long-term
volume reduction when
maintained as green space or
when runoff is treated through
other green infrastructure
practices
Detention Basin
and Basin
Retrofitting
Basins designed as dry extended
detention basins promote infiltration
of a portion of the volume into the
soil, achieving a runoff volume
reduction of nearly 30% in some dry
basins. Modelled Cityshed basins
show CSO reductions due to
detention of stormwater.
X X X X
High – Cost effective CSO
reducing practice. Detention
basin retrofitting, where
beneficial, is a feasible option
as a green practice for
reduction of CSO volume.
Table 5-2 Green Infrastructure Practice Applicability to Full CSO GI Program Implementation Plan
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5.4 Program Components
Through work during the Pilot and EAP, MSD has identified several program components to
implement in the CSO GI Program, which will be described in detail in this section.
Indirect Projects
Demolitions
Direct Projects
Education and Outreach
In addition to the four program components defined above already, MSD recognizes additional GI
practices which may be implemented within the targeted CSO regions. In an effort to maximize
water quality benefits and CSO Volume Reduction for Mississippi River Combined Sewer outfalls
for the $100 million program, MSD has elected to account for the CSO Volume Reduction from
these projects while not funding them from the $100 million. Some of these “creditable” GI practices
were identified within Section 12 of the LTCP, such as the City of St. Louis Pervious Alleys project
and the Hebert Stormwater Detention Basin project, while others were identified during the Pilot
such as the St. Louis Great Streets Initiative. MSD will continue to identify and quantify these
benefits as they present themselves.
5.4.1 Indirect Projects
Indirect Projects are projects that MSD has and will provide partial or full payment for the design
and construction of GI components that have CSO Volume Reduction benefits with MSD
conducting construction inspections. The property owner will maintain these GI practices as
required through a maintenance agreement with MSD.
5.4.1.1 Green Infrastructure Grants Program
As part of MSD Project Clear’s Rainscaping effort, past and future partnerships between MSD and
private entities will provide opportunity to incorporate GI into sustainability programs and future
redevelopment projects. The advantage to this approach is immediate incorporation of GI among
new development and redevelopment, which takes advantage of current opportunities and provides
for the social and economic needs of the community.
Similar to the Early Action Grants program implemented during the Pilot, MSD will continue to
offer reimbursement for specified GI elements that are eligible for funding, which included
impervious area reduction, pervious pavement, reinforced turf, planter boxes, amended soils,
bioretention/rain gardens, impervious area sheet flow to buffer, rooftop disconnection to rain
barrel/cistern/splash to grade, green roofs, blue roofs, green streets, curb extensions/street bumpouts,
educational signage for GI, and other techniques as approved by MSD.
The Early Action Grants has set a framework for opportunities to build partnerships and incorporate
GI in joint ongoing programs and future development/redevelopment projects. Moving forward,
MSD plans to enhance the program with consideration to minimize the application review time
required, modifications to rigid time frame for application submittal, and construction start times.
Based on the experiences of the Early Action Grants, MSD plans to modify the public-private
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partnership process in an effort to improve participation and the cost effectiveness of the program
implementation.
As part of that modification, MSD plans to have two methods for establishing these partnerships and
providing reimbursement for GI that reduces CSO Volume pursuant to this document. MSD’s intent
in these modifications is to create a certainty and expectation in the community about how MSD will
partner on GI. It is believed that this clarity will assist decision makers and developers in making
wise decisions to use GI. Through the implementation of an MS4 program, MSD’s Development
Review is ideally suited to the implementation of the program. The BMP Toolbox of acceptable GI
practices is maintained as public outreach and provides the technical tools needed by the community.
The first method, which will be available for establishing public-private partnerships with MSD for
GI, will come as a part of the private development review process. MSD will facilitate the
application process with developers as they submit development projects which incorporate GI
within the Mississippi River CSO regions. As projects are submitted, MSD will communicate to the
developer and project owner the intent of the CSO GI Program and offer to reimburse them for the
GI elements of their project that will reduce CSO volume. At the present time, MSD intends to
reimburse on a unit rate per cubic foot of annual volume reduction during the typical year. The rate
which MSD currently intends to use is up to $3.50 per cubic foot of annual runoff reduction and is
believed to be both consistent with MSD’s long term CSO control goals and fair reimbursement as
compared to actual observed costs during the Pilot.
The second method which MSD intends to make available for establishing public-private
partnerships is through an application process similar to that of the Early Action Grants. The
application period will be open as funds are available one or more times per calendar year. The
intent of the application process is to take advantage of partnerships which might not be available
otherwise such as with non-profit organizations and community organizations which would not have
funding for a project without the partnership. Additionally MSD believes more innovative
technologies will be used through the application process than might be used in a more traditional
private development submittal. This application process with also provide a larger emphasis on
social benefits such as education and community participation. The application process will use the
project ranking and benefit criteria developed for the Early Action Grants and will reimburse up to
100% of GI costs for approved projects.
5.4.1.2 Targeted Partnerships
Successful implementation of the CSO GI Program incorporates communication and collaboration
with a variety of partners. To move towards MSD’s volume reduction goal, partnerships are an
opportunity to advance the program.
Partnering to identify or engage with existing plans/programs is an essential part of the CSO GI
Program, and strategic targeted partnerships within the CSO Program Area can create additional
volume reduction opportunities. Targeting entities such as neighborhood schools, churches, and
community centers for the development of new programs or projects can yield additional buy-in and
engagement of the community. Also partnering on existing educational programs and plans are
considered to encourage implementation of GI on these properties to reduce CSO volumes. In
addition to reducing CSO discharge volumes, these strategic partnerships showcase the success and
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multiple benefits of GI and are an opportunity for MSD to provide education to the community about
GI practices, stormwater management, and water quality.
Partnerships with other government entities, such as the various municipal projects, provide
opportunities for GI to manage stormwater runoff on publically owned right-of-way (ROW) and
facilities. These partnerships can provide further community benefits in creating more pedestrian
and bike friendly streetscapes. Incorporating GI into these planned infrastructure projects can also
reduce the costs of GI retrofitting if it is done in collaboration.
Potential entities from which MSD hopes to seek input and with which MSD may seek partnerships
include, but are not necessarily limited to:
The City of St. Louis for projects in the City of St. Louis ROW, on City of St. Louis
properties including parks and municipal buildings, or in coordination with City of St. Louis
streets or other improvement projects. Also, the City’s Sustainability Plan, adopted in 2013,
will create numerous opportunities for coordination and implementing GI. Many objectives
and strategies speak to our common goals, such as Infrastructure Objective E, “Manage
Stormwater and Wastewater to Protect and Enhance Property and Natural Systems”.
Schools and Universities for potential projects on their campuses. St. Louis Public School
District, Charter and Private Schools, Saint Louis University, Ranken Technical College, and
Harris Stowe University all have campuses within the Program Area. Incorporating GI into
these campuses has the additional benefit of incorporating into educational curriculum, and
potential research opportunities for students.
Churches and Community Centers for potential projects on their campuses. Numerous
churches and community centers are located throughout the Program Area.
Missouri Department of Transportation and St. Louis County Highway and Traffic for
coordination on roadway improvement projects within the Program Area.
East West Gateway Council of Government (EWG) for assistance in coordination on
regional transportation projects and other regional watershed planning and economic
development planning. EWG is often involved in efforts to implement GI in the Program
Area, such as through Clean Water Act Section 319 funds.
Great Rivers Greenway (GRG) for coordination with trail projects within the Program Area.
GRG plans and implements trail and greenway projects in the City of St. Louis and St. Louis
County. They also partner with other entities on additional projects such as CityArchRiver
and Bike St. Louis.
5.4.2 Demolitions
Demolitions have been performed as a component of MSD’s CSO GI Program to reduce impervious
surfaces that generate storm water runoff and contribute to CSO discharge volume. The continued
use of GI money for building demolitions makes sense on many levels. Technically, the model
estimating runoff simply handles the demolished area as green, therefore, the runoff reduction is
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achieved the same as if an impervious area was treated by a GI facility. Economically, the cost of
the demolition to change impervious area to green is one of the lower cost methods on a dollar per
gallon CSO volume reduction basis. Finally, socio-economically, the demolition dollars can be used
to support current federal initiatives and local city planning initiatives alike. This money can be used
in a very critical and meaningful way by directly providing the funds that will achieve the strategies
contemplated in numerous planning efforts.
The City of St. Louis is the recipient of several program designations and grants from the White
House, the U.S. Department of Housing and Urban Development and others. Examples include: 1)
Choice Neighborhoods, 2) Strong Cities, Strong Communities (SC2) Initiative, and 3) Promise
Zones designation. Each of these programs in their own way is focused on revitalizing distressed
urban areas with new development and assisting economic growth. In all situations the ability to
effectively deal with underutilized, vacant and abandoned buildings is necessary to transform these
neighborhoods. St. Louis must replace distressed housing with high-quality mixed-income housing
that is well-managed and responsive to the needs of the surrounding neighborhood, with important
amenities and community assets, such as open space and parks.
Within the City of St. Louis’s NorthSide Regeneration Project Area, as a specific example for the
vision of St. Louis to redevelop its urban core, the City of St. Louis is working hard to be selected as
the site of the new National Geospatial-Intelligence Agency West Campus Headquarters (NGA
West). The City of St. Louis is one of four potential sites considered in the St. Louis region to build
a new location. Among numerous needs, the NGA requires an entire construction site that is
available for acquisition and construction within a very short timeframe. St. Louis as finalist for
NGA, must compete against rural greenspace and large tract suburban locations to attract this
development. The playing field is not level and the City of St. Louis must work hard to offer a
viable site. For the City of St. Louis to compete in attracting new businesses or new residential
developments to the area, it needs assembled, cleared, and strategically located tracts. MSD’s GI
funds for building demolition can play a role in this effort, when strategically combined with
environmental and community planning efforts.
MSD planning efforts under the CSO GI Program must align with Regional and City of St. Louis
Planning efforts. Examples include: 1) the HUD funded $4.7 million regional OneSTL Plan, 2) the
City of St. Louis Sustainability Plan, and 3) the City of St. Louis Strategic Land Use Plan. Related
to building demolitions, these plans view open space as a recreational amenity with opportunities for
integrating stormwater management. The objective is to improve residents’ access to quality parks
and recreational opportunities by providing easy access to greenspace, trails or parks within a half
mile of most residents. Based on community input, residents who live close to open spaces and
natural amenities see great value in preserving them. The City of St. Louis plans include specific
objectives to encourage creative, smart, and sustainable uses for under-utilized land and buildings.
The City of St. Louis intends to turn its many vacant parcels from a liability into one of its greatest
assets. Also, from a health and safety perspective for residents, the City of St. Louis plans to tear
down and/or redevelop hazardous vacant buildings, determine the optimal density for sustainable
neighborhoods, and strategically consolidate vacant and open space for infill housing. Many plans
exist and more are under development. What St. Louis needs are the funds for putting these plans to
work through implementation. The CSO GI Program funds for demolition will be available for this
purpose within the framework of City of St. Louis Planning and MSD’s CD compliance.
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These demolitions can provide desirable locations for GI practices and can yield long-term volume
reduction when maintained as green space or when runoff from future development is treated
through other GI practices. Therefore, demolitions will be handled one of two ways during the CSO
GI Program:
1. If the demolition is needed in order to construct a GI facility as part of the CSO GI Program,
the cost of that demolition will be included in the cost of that facility.
2. If a demolition paid for by the CSO GI Program as a “standalone” GI practice, the parcel will
be preserved as permanent green space, or will require a deed recorded agreement to provide
for future impervious surfaces to be treated, as in the Pilot. MSD intends to limit the total
expenditure on demolition in this category (i.e. demolition that is not a component of
constructing a GI facility) to 15% of the $100 million program providing for an additional
$13.5 million.
5.4.3 Direct Projects
Direct Projects are GI projects designed by MSD or a consultant, and constructed by an MSD
contractor. These projects are owned and maintained by MSD through a partnership with the City of
St. Louis on property acquired through the LRA. MSD will continue to perform Direct Projects to
achieve CSO Volume Reduction goals in this plan.
5.4.3.1 Neighborhood-scale Projects
MSD will continue to seek out and evaluate where Neighborhood-scale projects may make sense.
These projects are designed to receive stormwater flow from multiple lots. Neighborhood-scale
projects ensure stormwater is slowed, infiltrated and managed. These projects will beautify a
community when maintained as an amenity, and may provide economic benefits when associated
with redevelopment. The parcels in the drainage area of each facility will have a development
agreement recorded that limits the amount of impervious surface allowed and requires any future
downspouts to drain to the surface.
5.4.3.2 MSD Properties – Operating Facilities
MSD has 46 existing facilities in the Mississippi River CSO regions, including pump stations, a
wastewater treatment facility and an office building. Flow management at some MSD facility
buildings and sites can reduce the amount of storm water entering the Combined Sewer System
through a mix of roof and site drainage management. To date, MSD has not designed or constructed
projects incorporating GI practices at MSD facilities within the Mississippi River CSO regions.
In a 2008 MSD report entitled “Greening the District”, options for incorporating GI practices at
District buildings was assessed. Effective volume reducing green practices were recommended,
including green roofs, bioretention and permeable pavement. MSD will continue to consider
incorporating GI on new facilities that are constructed within the CSO GI Program Area. However,
opportunities on existing MSD facilities are limited. For example, the Bissell Point Wastewater
Treatment plant has a separate storm system; therefore, GI will not reduce CSO volumes. The
Bissell Floodwall pump stations are generally not good locations for performance or other benefits,
or similarly have a separate storm discharge to the river, below the combined sewer interceptor. The
best existing MSD facility with an opportunity for GI is MSD’s main office building.
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5.4.3.3 Detention Basin Retrofit
Detention basin retrofitting, where beneficial, is a feasible option as a green practice for reduction of
CSO volume. Basins designed as dry extended detention basins promote infiltration of a portion of
the volume into the soil, achieving a runoff volume reduction of nearly 30% in some dry basins
(Fernandez, 2012). MSD owns a number of detention basins constructed under its Cityshed
Mitigation Program.
5.4.4 Cityshed Mitigation Program
The Cityshed Mitigation Program involves voluntary homeowner buyouts of potentially several
hundred properties over the life of the program. This program helps homeowners through property
purchase and relocation. The property effectively converts impervious area to permanent green
space. These properties are often located in the former creek beds of natural hydrology that has long
been removed. Restoring these areas to green space makes sense. Through the Cityshed Mitigation
Program, MSD plans to use the buyout areas for detention basins to store separated stormwater
runoff from streets and control the flow into the Combined Sewer System.
The goal of the MSD Cityshed Mitigation Program is to alleviate the effect of frequent wet weather
surcharging of the combined sewer system and overland flooding. Under the CD, MSD is required
to spend $230 million in the combined sewer area sub-watersheds over the life of the CD. The
Cityshed Program began homeowner outreach for voluntary buyouts in 2013, estimating over 200
properties will be involved in current planned projects. These programs help homeowners through
property purchase and relocation.
The Cityshed Mitigation Program primarily uses partial separation of stormwater to achieve its
goals. Partial separation means to “soft separate” the storm drainage from streets thereby removing
the drainage from the combined sewers flows and directing the surface stormwater flow to a park,
green space, or detention basin. Street inlets are disconnected from the existing combined sewer
system and connected to a storm-only sewer system. A large regional detention basin is constructed
to detain stormwater flows and alleviate surcharging of the combined sewer, which would result in
flooding and CSOs. GI can be incorporated by redirecting surface runoff to a park parcel or
detention basin graded to detain/retain water and may include tree plantings and other native
vegetation. Through combined sewer system modeling, MSD has seen a reduction in CSOs volume
as a result of soft separation projects and views this as an effective GI practice to help meet CSO
Volume Reduction goals.
Four soft separation projects were constructed between 1997 and 2003 – Ashland-Abner, North
Pointe, Oriole, and Broadway. The next planned project, Harlem-Baden Relief Phase IV, routes
stormwater flows that exceed the sewer capacity to the detention basin. Construction is currently
proposed to begin in 2015 with an estimated completion by 2025. The Harlem-Baden Relief project
reduces peak flow in the South Harlem trunk sewer downstream of the project area and reduces CSO
volume from the outfall to the Mississippi River. The existing projects were designed for flood
detention and reducing peak flows during rain events. No projects to date have been implemented
using partial separation to a park or green space.
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5.4.4.1 Green Infrastructure on Cityshed Mitigation Program Properties
Cityshed Mitigation Program areas can also present excellent opportunities for GI to be co-located
when basins cannot be most effectively constructed on the property. There is an opportunity to
incorporate GI elements into Cityshed Mitigation projects, such as converting buyout properties to
green space or installing bioretention on those properties found to be unsuitable for flood control
structures. In addition, detention basins can incorporate designs that naturalize the basins. These
project types, within the CSO GI Program Area, can result in CSO Volume Reduction and contribute
to MSD’s long-term CSO volume reduction goals. When specific GI practices are constructed on
these properties for the purpose of GI and CSO volume reduction, the expenses will be accounted for
under the CSO GI Program, rather than the Cityshed Mitigation Program.
5.4.5 Project Selection Ranking
As outlined in this report, MSD has identified certain CSO regions draining to the Mississippi River
which have greater potential for reducing CSO discharge volume through the use of GI. While the
overall goal of the CSO GI Program is to reduce the volume of CSO discharge to the Mississippi
River, MSD recognizes other potential environmental and social benefits to GI. GI can improve
community livability, air quality, reduce urban heat island effects, improve water quality, reduce
energy use, and create green jobs (EPA 2014).
MSD currently has a rank and benefit points method that was developed and in use during the Early
Action Grants program. This method proved successful during the Pilot. The projects under the Pilot
were given benefit points for work in CSO regions with higher expected CSO Volume Reduction
from GI as demonstrated through computer modeling and the Bissell opportunity analysis
(LimnoTech, 2009). The benefit points are also given to prefer municipal and local government and
non-profit entities. Additional points are given to projects with public education and communication
activities, stormwater monitoring, high project visibility, ability for future expansions, and long term
sustainability.
Because of the success of the current rank and benefit points method, MSD intends to continue using
the ranking and benefit points methodology for the full scale CSO GI Program in order to maintain
an equitable implementation of GI across the CSO regions. As the need arises, MSD will modify the
benefit points to ensure the program’s ability to meet CSO control measure performance criteria.
5.4.6 Operations and Maintenance
To ensure that GI practices constructed are not removed and are maintained, maintenance
mechanisms must be in place.
5.4.6.1 Privately Owned Green Infrastructure
Privately owned GI facilities are the responsibility of the property owner to maintain. With the
exception of Rainscaping Small Grant funded projects, privately-owned projects which MSD
provides funding for GI components require a signed Maintenance Agreement. Before MSD
approves development plans, the property owner is required to execute a Maintenance Agreement
with the District that ensures the private stormwater management facilities will be maintained. Once
executed by the property owner and MSD, these maintenance agreements are recorded at the
appropriate city’s Recorder of Deeds office. The required Stormwater Management Facilities
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Report, with O&M Plan included with the project plans, must include a maintenance schedule and
specify maintenance activities.
With the signed Maintenance Agreement, the property owner agrees to maintain the GI practice
located on the property with the understanding that penalties may occur if maintenance is not
performed. An example of a recorded Maintenance Agreement is in Appendix G. All facilities with
a Maintenance Agreement are placed on an inspection schedule with MSD’s Division of
Environmental Compliance, ensuring that MSD staff will periodically inspect the projects.
Inspections are conducted to ensure they have not been removed and are functioning per design
plans.
5.4.6.2 MSD Owned Green Infrastructure
MSD-owned bioretention basins will be maintained by a contractor through 2016. At the time the
contract has ended, MSD will determine if a contract will be renewed or if MSD’s Operations
Department will take over all maintenance activities. The Operations Department currently conducts
non-routine maintenance, such as silt removal, inlet cleaning, and large debris removal. MSD will
also conduct routine inspections of all facilities to ensure facilities are operating per design and
properly maintained.
5.4.7 Public Education and Outreach
Implementation of the CSO GI Program incorporates communication and collaboration with a
variety of partners at the federal, state, regional, city, neighborhood, and individual levels. It is
expected that to move towards MSD’s volume reduction goal participation from partners at all levels
will be needed.
MSD aims to provide clear, up to date information to the public while improving water quality and
solving customer problems associated with wastewater and stormwater. Active stakeholder
engagement is an important factor to the long-term success of green infrastructure projects.
According to the Water Environment Federation, when there is active engagement and partnership
with the public through goal setting, planning or implementation, it helps build community capacity
and responsibility (Brown, 2014).
Public outreach mechanisms will include public meetings, stakeholder and community presentations,
educational website and printed communications. The purpose of these activities will be to educate
the public about existing sewer conditions and GI solutions; solicit input from residents and
neighborhood groups where projects are undertaken; and explore opportunities for additional action
by MSD and the public. MSD will tailor outreach to effectively target stakeholders associated with
specific GI projects and programs.
To encourage support for the CSO GI Program, several programs currently exist that can be
leveraged to enhance public outreach, education, and involvement, including the following:
5.4.7.1 MSD Project Clear
MSD Project Clear is the initiative to improve water quality and alleviate many wastewater concerns
in the St. Louis region. Project Clear is MSD’s activities to comply with the CD. MSD will invest
billions of dollars over a generation in planning, designing, and building community rainscaping,
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system improvements, and an ambitious program of maintenance and repair. Information is
provided to the public via the Project Clear website, email updates, public meetings and social media
outlets. Plus, key strategic partners are updated and involved in the program through a group that
periodically meets, called the Stakeholder Engagement Committee (SEC).
5.4.7.2 Rainscaping Small Grants Program
The Rainscaping Small Grants Program encourages the use of simple rainscaping techniques by
individual landowners. The program’s focus is to help educate the public to understand how
stormwater impacts the combined sewer system and associated issues. It aims to engage the
community and help them understand how they can be a part of the solution through the use of
rainscaping techniques on their properties. The Rainscaping Small Grants Program provides
workshops and more in-depth education on the rainscaping topic. Participants are expected to be
informed and influential advocates for rainscaping. This level of community involvement and
education is important for the long term sustainability of the program to ensure the practices are
acceptable to the community for implementation and then maintained as an amenity over time.
5.4.7.3 Other Outreach Opportunities
MSD will continue to partner with all stakeholders to identify and engage with existing plans and
programs. Appendix D presents a listing of some of the key partners and their current and/or
potential role in GI implementation to advance the program. MSD will maintain relationships with
governmental and nonprofit partners at all levels:
Federal
State
Regional
City
Nonprofit
Educational Institutions
Neighborhood-scale
MSD also will maintain GI outreach across the District for MS4 program stormwater quality, which
will complement activities related to CSO control measures. For example, MSD will maintain its
Stormwater BMP Toolbox, a website that was created to provide resources to help the public, design
engineers, and land developers on the post-construction stormwater BMP’s design, installation, and
maintenance. The BPM Toolbox houses several documents and tools including MSD’s Site Design
Guidance, Landscape Guide for Stormwater Best Management Practice Design, MEP Calculation
Spreadsheets, Stormwater Management Facilities Report template, and Maintenance Agreement
requirements. All content on the site is continually updated as needed to aid BMP owners,
landscapers and developers in implementing GI practices.
In addition, through MSD’s implementation of the St. Louis County Phase II Stormwater
Management Plan, MSD conducts educational workshops to inform the public on stormwater
management, water quality and GI. All land development projects requiring stormwater BMPs are
reviewed by MSD’s Development Review Team. This included BMPs in the separate sewer area,
which total over 3,800 that have been approved by MSD. With most of these BMPs being designed
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for volume reduction, MSD views these practices and performance as able to be duplicated in the
combined sewer areas.
5.4.8 Other Green Infrastructure Activities
In addition to the program features defined already, MSD recognizes additional GI practices which
may be implemented within the CSO GI Program Area. These activities will not take place as part
of the CSO GI Program, but may have water quality benefits and provide CSO volume reduction for
Mississippi River outfalls. Because of these benefits, MSD wants to identify these potential other
activities. Some of these other GI practices were identified within Section 12 of the LTCP, such as
the City of St. Louis Pervious Alleys project, while others were identified during the Pilot such as
the St. Louis Great Streets Initiative. Many of the current and potential programs and GI projects in
the Program Area that are known at this time are outlined in this section.
5.4.8.1 Tree Planting
Tree planting aids in the reduction of storm water as a result of the interception of rainwater as it
falls and uptake through the roots. Tree planting could include trees in ROWs and clusters of tree in
open spaces. MSD has not performed or paid for any projects solely using tree planting as a practice
for CSO volume reduction. Using funding from the Missouri Department of Conservation, the City
of St. Louis has updated tree inventory data (street trees) for five wards each for the last three years.
As a result, new GIS data for 15 wards has been gathered. The City of St. Louis plans to complete
an additional five wards each year.
In 2010, Forest Releaf of Missouri conducted an Urban Tree Canopy Assessment for the City of St.
Louis and some surrounding suburbs in St. Louis County. The study sought to determine where tree
planting efforts could and should be prioritized based on existing coverage and presence of potential
planting sites. The project area includes the CSO GI Program Area. According to the study, Forest
Releaf of Missouri recorded 26% urban tree canopy in the CSO GI Program Area. This is
significantly lower than the 40% American Forest recommended. The study identified a capacity to
increase the urban tree canopy by 10%.
With the use of Urban Tree Canopy data and findings and as GIS from the City of St. Louis’s
inventory is updated, MSD can plan for and collaborate on plans for tree planting, especially in
priority sub-sheds, for CSO Volume Reduction.
5.4.8.2 Downspout Disconnections
Downspout disconnections can reduce stormwater runoff volume, and thus CSO discharge volume,
by redirecting runoff from impervious roof areas to non-impervious areas for infiltration. If
downspout disconnections are done throughout the Program Area, MSD could provide funding for
disconnections for residential properties and industrial properties. The City of St. Louis has
modified local ordinances to allow for downspout disconnections where meeting strict criteria and
availability. While downspout disconnections may occur and are encouraged, MSD may not be able
to quantify the CSO Volume Reduction resulting from this practice. This practice is best if used as
part of another stormwater best management practice, i.e. disconnection to a rain garden.
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5.4.8.3 Existing Green Infrastructure
City of St. Louis Pervious Alleys
In 2008, the City of St. Louis developed a pilot program to test the effectiveness of different
pervious pavement systems in alleyways and to find ways that GI can be incorporated into
improvement projects. Three pervious alleys in the Compton Heights area were constructed under
this program. The project team included East-West Gateway, City of St. Louis Board of Public
Works, Southern Illinois University – Edwardsville (SIUE), MSD, and CH2M Hill. The goal of the
study was to compare flow and water quality before and after permeable pavement installation in
three City of St. Louis alleyways. The pilot study gathered data with the intention to support a
policy change to require the use of pervious paving for alley replacements, ultimately resulting in
over 700 acres of pervious paving in alleys citywide. Partially funded by EPA through the Missouri
Department of Natural Resources (MDNR) 319 Grant, four additional pervious alleys were
constructed in the Tower Grove Heights neighborhood. MSD conducted monitoring of one of the
pervious alleyways. Monitoring completed observed a 94% runoff volume reduction. These 7 sites
and additional runoff from future sites in the CSO GI Program Area are potential credits to meet
MSD long-term CSO Volume Reduction goals.
319 Grant & Great Streets Initiatives
East-West Gateway launched the St. Louis Great Streets Initiative in early 2006 to expand the way
communities think and design streets. South Grand Great Street project was completed in 2014 in
partnership with the South Grand Community Improvement District, the City of St. Louis, East-West
Gateway, and MSD. This voluntary project incorporated bioretention and permeable pavement
sidewalks as green practices to reduce stormwater runoff volume to the combined sewer. Funding
was also provided by the U.S. Environmental Protection Agency (EPA) Region 7, through MDNR,
under section 319 of the Clean Water Act (Section 319 Grant). This project and future voluntary
projects funded by Section 319 Grants to address stormwater volume can result in CSO volume
reduction. These projects will help MSD in reaching long-term CSO Volume Reduction goals.
Private Development – MSD “P-Jobs”
MSD works to lead efforts to balance water quality protection and volume, and Clean Water Act
compliance, with economic growth through land development. Channel protection, water quality
and flood detention requirements on development and redevelopment projects are outlined in MSD’s
Engineering Rules & Regulations. GI practices, such as bioretention and pervious pavement, can
also be used to meet some detention requirements.
Since 2006, MSD has approved over 3,800 stormwater BMPs on development projects. This
number includes regulatory and some voluntary BMPs in the separate and combined sewer area.
Those volume reducing GI practices and detention basins existing in the CSO GI Program Area can
assist MSD in reaching long-term CSO Volume Reduction goals. Within the CSO GI Program
Area, MSD estimates the construction of these CSO reducing practices, managing over 83 acres of
impervious area, have generally kept pace with the overall 1% increase in impervious area in the
area since the original modeling of the Mississippi CSOs.
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5.5 CSO Volume Reduction Green Infrastructure Program Action Plan
The purpose of this plan has been to document information and processes developed by MSD to
provide guidance for the successful implementation of the Mississippi River CSO Green
Infrastructure Program Control Measure. This plan has and will continue to guide MSD’s future
actions toward the $100 million full-scale implementation of the CSO GI Program. MSD will
outline potential future actionable items for it to perform in order to maintain progress towards
fulfilling the CD obligations. With the significant lessons learned during the Pilot, it is very clear to
MSD that long range planning for particular projects is very difficult to incorporate into the
community’s plans and future economic development to realize the full social and economic benefits
of GI. For planning purposes, MSD will outline near term actions within a 5-year timeframe, and
manage the balance of the GI Program over the long term through adaptive management.
5.5.1 Near Term Action (2016 – 2020)
During the near term period, MSD has secured funding for the CSO GI Program at the rate of $5
million per year through the completion of a 4-year Rate Commission process for fiscal year 2017-
2020, whereby the public has provided input for the rates to be set by MSD to collect revenue for the
wastewater program. The MSD Board has accepted the Rate Commission report, and annually the
Capital Improvement and Replacement Program will provide the budget for GI projects. MSD has
also identified several action items which should be accomplished within the near term period (2016-
2020) to ensure successful completion of CSO goals and commitments. The following list is some
of those items:
Education and Outreach -
1. Organize a press release regarding the submittal of this report, and subsequent approval by
EPA, to raise awareness about the GI Plan and create interest in the community around the
GI Plan to improve opportunities for partnerships to build GI.
2. Post this report and other pertinent GI documents on MSD website, including hotlinks to key
sections and pages of the report (e.g. maps showing locations of GI practices) to provide a
user-friendly interface for stakeholders and the public.
3. Contact representatives from other combined sewer operators with grant programs to discuss
strategies to maintaining high levels of participation in GI grant programs.
Indirect Projects –
Green Infrastructure Grants Program – Development Review
1. Develop and implement a process and internal procedures for a streamlined reimbursement
program within MSD’s normal Development Review process, to reimburse projects for CSO
volume reductions at a specified dollar amount per cubic foot of CSO reduced.
a. Establish a procedure and basis for setting and updating the reimbursement rate, to be
initially set at $3.50 per cubic foot of annual CSO volume reduced. Identify the
necessary data to be collected to inform future adjustments to the rate. Adjust rates
as needed based on interest level and results achieved.
b. Develop an application form or other mechanism with required information for
project evaluation to ensure program goals are met, and for tracking results.
c. Develop internal procedures for plan review engineers to ensure consistent
implementation to meet program goals
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2. Publicize and notify the development community (engineers and developers) about this new
CSO GI reimbursement program available through Development Review. Make
presentations of the MSD Green Infrastructure Grant Program to engineering and
development communities.
Green Infrastructure Grants Program – Annual Appeal
3. Submit 4th round of Early Action Grants to EPA for approval in January 2016. Six projects
will be proposed for funding.
4. Maintain an annual competitive appeal for the Green Infrastructure Grants Program, modeled
after the Early Action Grants program. Adjust program according to the lessons learned in
this report. Roll out program in August 2016.
Small Grants Program
5. Submit 2nd round of Rainscaping Small Grants to EPA for approval in January 2016.
Funding proposed at the same amount as 1st round, $250,000 for grants and administration.
6. Maintain and continue the Rainscaping Small Grants Program to involve citizens and
community groups in rainscaping, for educational purposes and capacity building for GI
within the community.
Targeted Partnerships
7. Conduct a high level planning meeting between MSD Director of Engineering and City of
St. Louis Senior Management, along with key City Departments/Divisions to explore
targeted partnership opportunities, considering all the GI practices applicable.
8. Identify and investigate schools, universities, churches, community centers and large
property owners for potential targeted partnerships within the CSO GI Program Area. GIS
analysis concludes that there are more than 600 schools, churches, parks and other similar
use properties within the CSO GI Program area. Figure 5-1 shows some potential properties
on which MSD plans to investigate for the potential of partnering for the placement of GI
practices.
9. Contact prospective partners to discuss the GI Plan and to identify win-win opportunities that
will involve implementing GI. Discuss opportunities with past partners and organizations.
10. Contact East West Gateway Council of Government (EWG) for assistance in coordination on
regional transportation projects and other regional watershed planning and economic
development planning.
11. Contact Great Rivers Greenway (GRG) for coordination with trail projects within the CSO
GI Program Area. GRG plans and implements trail and greenway projects in St. Louis City
and St. Louis County. They also partner with other entities on additional projects such as
CityArchRiver and Bike St. Louis.
Demolitions –
1. Meet with the City of St. Louis to identify needs and coordinate the strategy for selected
demolitions.
2. Determine the logistics of the demolition program, and execute an agreement between MSD
and the City of St. Louis.
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Figure 5-1 Potential Properties for Targeted Partnerships
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Direct Projects -
Neighborhood-scale
1. As with the initiation of the Pilot, MSD will identify the LRA properties within the CSO GI
Program Area that are located on city blocks that were not reviewed in the Pilot for potential
Neighborhood-scale GI. The evaluation criteria and approach will be modified based on
lessons learned in this report. There are approximately 315 city blocks with LRA properties
which have not yet been evaluated for green infrastructure. Figure 5-2 shows some
identified city blocks on which there are LRA-owned properties.
2. Investigate blocks using GIS, aerial photography, etc. for potential locations.
3. Perform site visits of potential blocks to verify potential locations.
4. Develop Preliminary Studies of potential locations with preliminary sizing and cost
estimates.
5. Rank identified projects.
6. Determine five-year planning level budget and schedule for design of desirable projects.
MSD Operating Facilities
7. In accordance with MSD’s Owners Design Guidance Document, MSD will evaluate the
feasibility of GI at new facilities being constructed under the CD. Various GI projects in
conceptual planning or design include Maline Creek CSO BP 051 & 052 Local Storage
Facility (Chain of Rocks Dr. to Church Dr.).
8. For existing Operating Facilities, MSD will implement GI at its main offices at 2350 Market.
Various technologies will be considered, however, pervious pavement will likely be chosen
for resurfacing the employee and guest parking lot.
MSD Detention Basin Retrofits
9. MSD has constructed and maintains 5 detention basins in the CSO GI Program Area. The
basins will be evaluated for retrofitting, where beneficial, as a green practice for reduction of
CSO volume. Basins designs may incorporate a dry extended detention control structure to
promote infiltration of a portion of the volume into the soil. Alternatively, the location of
nested bioretention will be considered as a volume reducing technology also.
Cityshed Mitigation Program -
1. Implement the Cityshed Mitigation Program as required by the CD. The list of projects
currently programmed are as follows: Hebert Detention Basin (Horseshoe), Partridge
Avenue Detention Basin, Tillie Baden Newby Detention Basin, Frederick Street Detention
Basin, Calvary Cemetery Detention Basin, Essex Place Detention Basin, Ashland-Semple
Detention Basin, Ashland Clara Detention Basin, and the Jenning's Station Detention Basin.
2. Continue planning efforts to identify conceptual projects for the balance of the $230 million
Cityshed Mitigation Program commitment.
3. Evaluate the currently identified Cityshed Mitigation Program projects for potential co-
location of GI practices.
a. Continue efforts working with the City of St. Louis Urban Vitality and Ecology
Initiative to identify area where GI can be located on land purchased by MSD, but
not being used for a basin. Alternatively, design of basins will consider nested
bioretention.
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b. Determine the appropriate internal methods for tracking costs, to keep separate
accounting for $100 million for CSO volume reducing GI practice expenses and the
$230 million Cityshed Mitigation Program expenses.
Figure 5-2 City of St. Louis Blocks with LRA Properties
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5.5.2 Long Term Action (2021 – 2034)
In the long term period, MSD will continue to secure promote the funding through the Rate
Commission process to complete the $100 million CSO GI Program. MSD also anticipates
identifying further Cityshed Mitigation Program projects which may provide additional sites for co-
location of GI practices. MSD intends to continue active community involvement to identify further
opportunities and to encourage participation in the Green Infrastructure Grants program.
5.5.3 Adaptive Management
MSD’s CSO GI Program has many complex components and depends primarily upon development
and implementation of GI practices through partnerships with separate private and public entities.
Due to the uncertainty involved with the CSO GI Program, it is difficult to completely prescribe the
program at the outset, and as such MSD intends to use an adaptive management approach to modify
the program as necessary. Through continued evaluation, MSD will identify areas of needed
improvement and areas of success in the program to inform future decisions.
Since one primary mechanism for project identification and implementation is the Green
Infrastructure Grants program, part of MSD’s adaptive management strategy is to evaluate the
structure of our public-private partnerships. In particular, MSD will consider changes to the
program if it is found that participation is not consistent with our long term goals and performance
criteria. Potential tools for modifying the program would be changes to the rate at which MSD funds
the program, and different benefit points for projects. While MSD will monitor annual progress
toward our long term goals and performance goals and may make changes to the program when
prudent, MSD recognizes the need to allow sufficient time for program changes to be realized. To
date, MSD has appropriated over $21.7 million toward the program, and has set a goal to have an
additional $20 million invested in the program by the year 2020. In the event that the goal is not
met, MSD will begin a focused evaluation of the program to identify areas of needed change or
improvement in order to reach a total $100 million invested by the year 2034, the CSO Control
Measure Critical Milestone.
Figure 5-3 provides an initial frame of reference which MSD intends to use for implementation of
the CSO GI Program. The planned expenditures and time schedule for implementation were
developed using the best available knowledge gained from the Pilot and accounting for anticipated
opportunities. Nevertheless, the planned project expenditures and time frame are subject to change
if MSD finds that opportunities are different than anticipated or prompted by other adaptive
management changes.
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Figure 5-3 Initial CSO GI Program Plan
5.6 Projected CSO Volume Reduction
5.6.1 CSO Volume Reduction from Direct and Indirect Projects
This section describes the projected CSO volume reduction as a result of the expenditure of $100
million over the life of the CSO GI Program.
Using an efficiency parameter presented in Table 3.1 of Section 3.3, MSD came up with two
scenarios upon which to base an estimate for the total CSO volume reduction (during the LTCP
typical year rainfall) at the completion of the CSO GI Program. The estimates are based upon an
anticipated cost of $200,000-$250,000 per acre managed. MSD chose the scenarios presented to
reflect the reality that MSD does not have direct influence on where GI will be constructed since it
does not own properties throughout the Mississippi CSO regions. It is also believed that the range of
costs which were informed from observed costs during the Pilot will reflect the variability in
construction costs and that they will not change significantly in the near term program
implementation. Over time, inflation will likely impact the amount of area that can be managed with
$100 million of GI expenses.
The first scenario developed for distributing funds and managed area is to equally place GI over the
entire service area. This scenario reflects the fact that MSD does not own many properties and
therefore cannot prescribe where all of the GI funds will be spent; therefore all locations are given
equal priority and probability of placement. Using the estimated $93 million remaining after the
Pilot (and EAP) projects and 4% allowance for public education and outreach, and the rate of
$200,000-$250,000 per acre, MSD expects to manage an additional 372-465 acres of area. An
expected, CSO Volume Reduction can be estimated for the first scenario as 86-107 MG by using the
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0.231 efficiency parameter representing the weighted average of the entire CSO GI Program Area
developed in Section 3.3.
The second scenario for distributing funds recognizes that private development trends will have an
impact on the installation of GI. To account for this reality, the area expected to be managed within
each CSO region is proportional to both the area available to be managed and the percentage of
development which has taken place within those regions in the last 10 years, as reflected by number
of approved plans reviewed by MSD. Table 5.3 demonstrates this weighting and expected area to be
managed under the assumptions of the scenario. By combining Table 3.1 and Table 5.3, the
expected CSO Volume Reduction for this scenario is between 109-137 MG. Given that this scenario
is driven by development trends, it is expected that the majority of Indirect Projects would occur in
this manner.
CSO Region Total Drainage
Area (Ac)
Percent of
Development
Expected Area to be
Managed Based upon
Development Trends (Ac)
Central 8323.4 58.7 300.2 - 375.3
Gimblin 172.9 0.0 0
Southern Arsenal 1784.8 4.1 4.5 - 5.7
Utah 202.9 0.2 0
Louisa, Trudeau, Barton 598.3 1.8 0.7 - 0.9
Dakota 226.8 0.2 0
Rocky Branch, Salisbury 2748.5 9.7 16.4 - 20.5
Harlem Creek 4746.6 10.0 29.1 – 36.4
Humboldt, Baden 4360.2 5.8 15.5 – 19.5
Ferry 534.5 2.0 0.7 - 0.9
Prairie 353.7 1.2 0.3
Biddle, Chambers South
Benton 1171.4 6.4 4.6 – 5.7
Table 5-3 Expected Area to be Managed from Development Trends over Previous 10 years
Combining the volume estimates from the two scenarios described above with the volume reduction
achieved during the Pilot, MSD expects to achieve 90-141 MG of CSO Volume Reduction during
the typical year at the completion of the CSO GI Program. For comparison, the initial estimates
from the LTCP were 85-222 MG. The estimate of 90-141 MG is based primarily on the assumption
that observed costs over the duration of the CSO GI Program will not vary greatly from $200,000-
$250,000 per acre and that MSD will find opportunities distributed throughout the GI Program Area
such that the expected performance goals are met. As the CSO GI Program moves forward, the
projected estimate will become more precise.
5.6.2 CSO Volume Reduction from Other Green Infrastructure Activities
MSD’s LTCP states that for the CSO GI Program, a “goal is to reduce CSO overflow volumes to the
Mississippi River by 10 percent” and that “this goal will be updated based on the results of projects
comprising the pilot phase of the program”. It became apparent to MSD after the Pilot that the $100
million CSO GI Program can achieve approximately 90 MG CSO Volume Reduction of the
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estimated 6,950 MG total CSO discharge volume to the Mississippi River during the typical year.
MSD recognizes other GI activities are taking place throughout the CSO GI Program Area. Two of
these projects were identified in the CSO LTCP, the Horseshoe Project, and the City of St. Louis
Pervious Alley Project, and others have been identified earlier in this Section 5. These other GI
activities will have significant benefits in terms of CSO Volume Reduction.
MSD has estimated the CSO Volume Reduction from the presently identified Cityshed Mitigation
Projects as 278 MG. The estimates of the CSO Volume Reduction are presented in Table 5.4. The
projects already identified comprise approximately $110 million of the full $230 million Cityshed
Mitigation Program. By extrapolation, it is anticipated that the Cityshed Mitigation Program will
continue with projects similar to those already identified, thus the total program is projected to
provide approximately 556 MG CSO Volume Reduction during the LTCP typical year.
Cityshed Mitigation Program
Projects
Anticipated
Construction
Completion Year
Expected CSO Volume
Reduction (Million Gallons)
Hebert Detention Basin (Horseshoe) 2025 134
Partridge Avenue Detention Basin 2025 18
Tillie Baden Newby Detention Basin 2025 18
Frederick Street Detention Basin 2025 18
Calvary Cemetery Detention Basin 2025 18
Essex Place Detention Basin 2025 18
Ashland-Semple Detention Basin 2025 18
Ashland Clara Detention Basin 2025 18
Jenning's Station Detention Basin 2025 18
Total Estimated CSO Volume
Reduction for Typical Year 278
Table 5-4 Estimated CSO Volume Reduction for Identified Cityshed Mitigation Projects
Currently there are 7 completed pervious alley projects from the City of St. Louis Pervious Alley
Project which manage an estimated 17 acres of drainage area. The CSO Volume Reduction
estimated for these projects using the methods described in Section 3.3 as 4 MG, or approximately
equivalent to the CSO Volume Reduction of the Pilot.
5.6.3 Total Projected CSO Volume Reduction
The $100 million CSO control measure CSO GI Program for the Mississippi River will have a total
CSO Volume Reduction of approximately 90-141 MG during the LTCP typical year. In addition to
the water quality benefits from the CSO control measure, MSD anticipates that other GI activities in
the CSO GI Program Area will reduce the estimated 6,950 MG total CSO discharge volume to the
Mississippi River during the typical year by 650 MG (9.4%), as shown in Table 5.5. Therefore, the
original goal of 10% CSO reduction is reasonably expected when considering all types of green
activities within the area in addition to the CSO Green Infrastructure control measure.
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Program Expenditure
(Million Dollars)
Estimated CSO Volume
Reduction
(Million Gallons)
CSO Volume Reduction Green
Infrastructure Program $100 90
City of St. Louis Pervious Alley Project
(Currently Constructed) $0 4
Cityshed Mitigation Program (Presently
Identified Projects) $110 278
Cityshed Mitigation Program (Unidentified
Projects To Be Planned in GI Program
Area)
$120 278
Total Mississippi River CSO Volume
Reduction $330 650
Table 5-5 Estimated Total Mississippi River CSO Volume Reduction for Typical Year
5.7 CSO Control Measure “Green Infrastructure Program” Performance Criteria
The CSO Control Measure for the outfalls discharging directly into the Mississippi River, as defined
in the LTCP and CD, is the use of GI facilities to reduce runoff volumes intercepted by the combined
sewer system. In part, the purpose of this document is to identify the performance criteria for the
“Green Infrastructure Program” CSO Control Measure. As indicated in previous sections, MSD
expects to manage approximately 372-465 acres of total drainage area with GI practices using the
remaining $97 million for a CSO GI Program total, including the $4 million for education and
outreach. Including the 33 acres accomplished during the Pilot, MSD will manage a total of 405-
500 acres with GI. With an estimated 50% impervious area within the CSO GI Program Area, MSD
expects this to include a minimum of 202 to 250 acres of impervious area. Utilizing the expected
performance of GI from the hydrologic/ hydraulic model, between 90-141 MG of CSO discharge
volume are estimated to be removed during the LTCP typical year, based on the areas managed by
GI. MSD will implement the CSO GI Program to meet the CD CSO Control Measure performance
criteria to have a total expenditure of $100 million including the Pilot on qualified expenses by the
full operation achievement date of June 30, 2034. Table 5.6 identifies the CD performance criteria.
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Table 5-6 Performance Criteria Identified for CSO Control Measure
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6 GREEN INFRASTRUCTURE PROGRAM ADMINISTRATION & MANAGEMENT
MSD will manage the CSO Volume Reduction Green Infrastructure Program (CSO GI Program)
through the Engineering Department. The Planning Division will incorporate green infrastructure
(GI) into MSD’s conceptual project plans and will administer the CSO GI Program and the review of
Indirect Projects with GI stormwater management facilities. The Design Division will manage the
final design of MSD projects. The Construction Management team conducts inspections through
the construction phase of Direct and Indirect Projects. The Division of Environmental Compliance
conducts routine maintenance inspections of all GI practices on these projects. MSD Operations
performs maintenance activities for MSD owned GI.
6.1 Program Tracking
A major role of MSD in implementing the CSO GI Program will be to ensure that the performance
criteria and critical milestones will be met by June 30, 2034. As part of this administrative role,
MSD will be tracking costs and performance metrics which provide reference for where the CSO GI
Program is and to where it is heading as we implement projects.
6.1.1 Tracking Performance
There are several key factors which MSD will track to help assess the performance and ensure
sustainability of the CSO GI Program in achieving long term goals for Combined Sewer Overflow
(CSO) discharge volume reduction. Some of those key factors are designed drainage area and total
impervious area managed by GI facilities, location of constructed GI facilities, adherence to
approved maintenance plans for GI facilities, and total expenditure on qualified GI costs.
MSD intends to maintain a GIS database of all GI practices constructed by the CSO GI Program. As
part of the record keeping, designed drainage area and total impervious area directed to each facility
will be documented from the design plans.
Using the procedures outlined in Section 3.3 of this report, MSD will evaluate the actual CSO
Volume Reduction during the LTCP typical year rainfall for projects which have been completed,
and will also provide an updated estimate for the total Mississippi River CSO Volume Reduction
during the LTCP typical year at the completion of the CSO GI Program.
6.1.2 Tracking Expenditures
As required in MSD’s CSO Long-Term Control Plan (LTCP), MSD will spend a total of $100
million on GI as part of its CSO control measures for those outfalls which overflow to the
Mississippi River. The following categories of cost, as outlined in the LTCP will be tracked and
reported and will count toward the $100 million dollar commitment:
5-year Pilot (Total of $3 million);
Engineering;
Soils assessment and Restoration;
Legal costs associated with deed restrictions and easements;
Property acquisition;
Demolition – MSD intends to limit the total expenditure on demolition, which is not a
component of constructing a GI facility, to 15% of the $100 million program;
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Construction of GI;
Maintenance of GI (during first 5 years of operation);
Public participation activities; and
Monitoring of GI and associated laboratory analyses.
6.2 Green Infrastructure Program Annual Reporting
As part of the Consent Decree (CD), MSD submits an Annual Report to the United States
Environmental Protection Agency (EPA) by October 31st of each year with program updates,
progress summaries, projections of work for the following year, and data tables. MSD will include
progress toward the CSO Control Measure “Green Infrastructure Program” in the Annual Report.
As presently formatted, the Annual Report contains two tables of relevance to the CSO Control
Measure, Green Infrastructure GI Program. Table E-1 is titled “Status of CSO Control Measures
Performance Criteria” and Table E-2 is titled “Status of Green Infrastructure Program Costs”. The
performance criteria and cost information to be reported and the intended format of the tables are
described in the following sections. Examples of Table E-1 and Table E-2 from the Annual Report
are provided in Appendix X.
6.2.1 Status of CSO Control Measure Performance Criteria
The Annual Report will provide details for the progress of the CSO GI Program towards meeting the
identified Performance Criteria and the status of the Critical Milestone, “Achievement of Full
Operation - 6/30/2034”. The Performance Criteria identified during the Pilot and described in this
report is that the CSO Control Measure “Green Infrastructure Program” will manage at least 405
acres of total drainage area and 202 acres of impervious area using GI practices with an expenditure
of $100 million. MSD identified an additional performance metric which will assist tracking the
progress towards satisfying the long term CSO GI Program goal of CSO Volume Reduction. The
performance metric is CSO Volume Reduction during the typical year, as defined by the LTCP. The
performance metrics are described again in the following sections as well as details on what is to be
reported annually in Table E-1 of the Annual Report.
6.2.1.1 Total Drainage Area Managed
The estimated CSO Volume Reduction during the typical year, as estimated using the methods of
Section 3, are directly related to total drainage area directed to a GI practice. Total drainage area is
considered in the design of all GI practices and would be available from the design plans of any
Direct or Indirect Project. MSD has a goal of managing 405 acres of total drainage area with GI
practices at completion of the CSO GI Program as a part of the CSO Control Measure Performance
Criteria.
MSD intends to annually report the newly directed drainage area to GI facilities as well as the total
directed drainage area since inception of the CSO GI Program. MSD will also report annually a
projection of drainage area to be directed to GI facilities by the end of the next reporting year.
6.2.1.2 Impervious Area Managed
The effectiveness of GI at reducing runoff volumes, and therefore combined sewer volumes is
directly linked to the total impervious area which is directed to GI facilities. In addition to its direct
linkage to reduction in CSO discharge volume, impervious area directed to GI facilities is a physical
measurement which is readily obtained, making it a very useful metric in tracking the performance
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of the CSO GI Program. MSD has identified a specific goal of 202 acres of impervious area
managed by GI practices as a part of the CSO Control Measure Performance Criteria. MSD intends
to annually report the newly directed impervious area to GI facilities as well as the total directed
impervious area since inception of the CSO GI Program.
6.2.1.3 CSO Volume Reduction during Typical Year
The final performance metric to be reported is a direct estimate of CSO Volume Reduction during
the LTCP typical year achieved to date by the CSO GI Program. Using the techniques presented in
Section 3.3, MSD will estimate a total CSO volume reduction for the Mississippi River as a result of
the current status of the CSO GI Program. MSD will also estimate an increase in CSO Volume
Reduction for work completed during the reporting year and offer a projection for CSO Volume
Reduction during the typical year at program completion and $100 million expenditure, June 30,
2034. During the final year of the CSO GI Program, the estimated total CSO Volume Reduction and
the projected estimate of total Mississippi River CSO Volume Reduction at program completion will
become equivalent.
6.2.1.4 Status of Green Infrastructure Program Costs
To ensure that the costs are correctly accounted and that the $100 million has been spent, MSD will
also include Table E-2 in the Annual Report to report the status of Program Costs. As has been done
during the Pilot, this table is a summary table showing expenditures by year and general cost
category, as outlined in Section 6.1.2 and in the LTCP.
6.2.2 Final Reporting at Program Completion
The annual reporting metrics in Table E-1 and Table E-2 include the Performance Criteria for the
CSO Control Measure (total drainage area managed by GI, impervious area managed by GI, and
total expenditure). Therefore, the CSO Control Measure will have been verified as complete in the
final year of the CSO GI Program. The total qualified expenses will be presented and compared to
the $100 million required and the managed total drainage area and impervious area by GI practices
compared to the Performance Criteria of 405 acres and 202 acres, respectively. The Annual Report
for the year 2034 will serve as the final report and certification that the CSO Control Measure for the
outfalls on the Mississippi River has been satisfied.
6.3 Conclusions
MSD is very proud of the accomplishments of the Pilot. Significant reductions in CSO volume is
occurring and will occur as a result of the full-scale CSO GI Program implementation. The social
and economic benefits of GI have and will continue to add value to the City of St. Louis and its
residents. Several opportunities and methods of delivery for GI have been demonstrated and have
proven to be effective. The technology, logistics, and social and political implications have all been
successfully navigated. Monitoring efforts have confirmed better than expected results. MSD has
complied with its CD obligations, has developed a clear path forward for implementation of GI, and
has established a methodology to report its progress. We are truly thankful to everyone who was
involved in the development of the CSO GI Program. MSD is excited about the future of the Green
Infrastructure Program and is optimistic about its continued success.
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