HomeMy Public PortalAboutDeer & Black Creek ARAP_Final_12.20.2021
BLACK CREEK AND DEER CREEK
E. coli TMDL ASSUMPTIONS AND
REQUIREMENT ATTAINMENT PLAN
December, 2021
Prepared by Metropolitan St. Louis Sewer District in coordination with its MS4 co-permittees.
MSD & MS4 Co-permittees
Black Creek and Deer Creek E. coli TMDL ARAP
TABLE OF CONTENTS
1.0 Introduction and Purpose .................................................................................................................. 3
1.1 Black Creek and Deer Creek E. coli TMDL ............................................................................ 3
1.2 MS4 Permit Requirements ...................................................................................................... 6
2.0 E. coli Bacteria and its Potential Sources ........................................................................................... 7
2.1 Sanitary Sewer Infrastructure ................................................................................................. 7
2.2 Individual Sewage Disposal Systems .................................................................................... 10
2.3 Agricultural Runoff (Stabled Horses) ................................................................................... 11
2.4 Urban Stormwater Runoff .................................................................................................... 11
2.5 Riparian Conditions.............................................................................................................. 11
2.6 Illicit Straight Pipe Discharges ............................................................................................. 11
3.0 TMDL Implementation Activities ................................................................................................... 12
3.1 St. Louis County Phase II Stormwater Management Plan .......................................................... 12
3.1.1 MCM #1, Public Education and Outreach on Stormwater Impacts ................................ 12
3.1.2 MCM #2, Public Involvement/Participation in Program Development .......................... 14
3.1.3 MCM #3, Illicit Discharge Detection and Elimination................................................... 14
3.1.4 MCM #4, Construction Site Stormwater Runoff Control ............................................... 16
3.1.5 MCM #5, Post-Construction Stormwater Management in
New Development and Redevelopment ........................................................................ 16
3.1.6 MCM #6, Pollution Prevention Good Housekeeping for Municipal Operations ............. 18
3.2 Project Clear ............................................................................................................................. 18
3.2.1 Sanitary Sewer Overflow Control Master Plan .............................................................. 19
3.2.1.1 Sewer System Evaluation Survey (SSES).............................................................. 19
3.2.1.2 Master Plan Projects ............................................................................................. 20
3.2.2 Capacity, Management, Operations, and Maintenance Program ....................................... 22
3.2.3 Fats, Oil, and Grease Program ......................................................................................... 23
3.3 TMDL Best Management Practices Targeting Bacteria ............................................................. 23
4.0 Evaluation ...................................................................................................................................... 27
LIST OF FIGURES
Figure 1. Impaired reaches of Black Creek and Deer Creek as described in the Black Creek and Deer
Creek E. coli TMDL, and watershed location in St. Louis County, Missouri............................. 4
LIST OF TABLES
Table 1. TMDL requirements for E. coli bacteria at specific flows in Black Creek (WBID 3825) ............ 5
Table 2. TMDL requirements for E. coli bacteria at specific flows in Deer Creek (WBID 3826) ............. 6
Table 3. Summary of Sanitary Sewer Gravity Pipes by Pipe Diameter and Material in Black Creek and
Deer Creek Watersheds as of August 13, 2021 ........................................................................... 8
Table 4. Summary of Sanitary Sewer Pipes by Pipe Diameter and Material that have
Received Rehabilitation in Black Creek and Deer Creek Watersheds as of August 13, 2021....... 9
Table 5. Summary of Capacity and Non-Capacity Overflows and
Bypasses for Black Creek and Deer Creek Watersheds, 01/01/2018- 12/31/2020 ..................... 10
Table 6. TMDL Best Management Practices Targeting Bacteria in the Black Creek and Deer Creek
Watersheds .............................................................................................................................. 26
APPENDICES
Appendix A. SSO Control Master Plan Projects in Black Creek and Deer Creek Watersheds
Appendix B. Bacteria and Nutrient Best Management Practices Strategy Review
MSD & MS4 Co-permittees
Black Creek and Deer Creek E. coli TMDL ARAP
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1.0 Introduction and Purpose
Black Creek and Deer Creek first appeared on Missouri’s Section 303d list of impaired waters for
elevated concentrations of Escherichia coli (E. coli) bacteria in 2012. For Black Creek, in-stream
concentrations of E. coli have been found to exceed Missouri’s water quality criterion for its designated
use of Whole Body Contact Recreation Category B, which is set at 206 E. coli counts per 100 milliliters
of water (206 counts/100mL). For Deer Creek, in-stream concentrations of E. coli have been found to
exceed Missouri’s water quality criterion for its designated use of Whole Body Contact Recreation
Category A, which is set at 126 E. coli counts per 100 milliliters of water (126 counts/100mL).
According to Missouri’s 303d listing methodology, a water designated for Whole Body Contact
Recreation, Categories A or B, is determined to be impaired by bacteria if the geometric mean in a given
recreational season exceeds the water quality criterion (126 counts/100mL or 206 counts/100mL,
respectively) in any of the last three years with available data. At least five samples are needed from a
single recreational season, which is defined as the period from April 1 through October 31. Black Creek
and Deer Creek remained on Missouri’s Section 303d list of impaired waters for E. coli from 2012 to
2018. On June 26, 2019, the United States Environmental Protection Agency (USEPA) approved
Missouri’s Total Maximum Daily Load (TMDL) in Black Creek and Deer Creek watersheds for
Pathogens as indicated by E. coli1.
As required by the Federal Clean Water Pollution Control Act, the Missouri Department of Natural
Resources (MDNR) issues the Metropolitan St. Louis Sewer District (MSD), St. Louis County, and 59 St.
Louis County municipalities a general operating permit to discharge authorized stormwater from the
Municipal Separate Storm Sewer System (MS4) servicing the Plan Area to waters of the state. The most
recent permit (General Operating Permit MOR040005) was issued on November 1, 2021 and requires
regulated MS4s identified in a TMDL with an applicable Wasteload Allocation (WLA) to implement
steps toward the attainment of the applicable WLA in accordance with 40 CFR 122.44(k)(2) and (3). In
this case, MSD and its co-permittees are required to develop an Assumptions and Requirement
Attainment Plan (ARAP) to address applicable assumptions and requirements in the Black Creek and
Deer Creek Watershed TMDL for Pathogens as indicated by E. coli (referred to herein as Black Creek
and Deer Creek E. coli TMDL).
The purpose of this document is to fulfill requirements in the MS4 permit issued to MSD and its co-
permittees, specifically Section 6.1. MS4s Subject to Total Maximum Daily Loads (TMDL). This TMDL
ARAP will address the aggregated wasteload allocations assigned to the MS4 area in the Black Creek and
Deer Creek E. coli TMDL. Procedures and activities to be implemented in accordance with the MS4
permit are provided herein. Most importantly, this TMDL ARAP includes a description of
implementation activities and best management practices (BMPs) that will be used to target known
sources of E. coli bacteria specific to the Black Creek and Deer Creek watersheds, as well as a prioritized
schedule for their implementation. BMP effectiveness will be evaluated after implementation, and those
found to be ineffective will be revised or replaced accordingly. Both the Black Creek and Deer Creek E.
coli TMDL and TMDL Implementation Plan 2 were used in the development of this TMDL ARAP.
1.1 Black Creek and Deer Creek E. coli TMDL
Deer Creek is located in central St. Louis County. The most upstream extent of Deer Creek occurs at
Creve Coeur Golf Course in the City of Creve Coeur. From this point, Deer Creek generally flows to the
southeast towards its confluence with River des Peres at Interstate 44, located in the Lindenwood Park
neighborhood in the City of St. Louis . In tot al, Deer Creek is approximately 10.7 miles long. The reach
1 Missouri Department of Natural Resources Water Protection Program. 2019. Total maximum daily load (TMDL) for Black
Creek and Deer Creek, St. Louis County and St. Louis City. Pollutants of concern: Pathogens. Submitted: July 11, 2017.
Approved: June 26, 2019. 39pp.
2 Missouri Department of Natural Resources Water Protection Program. May 2, 2017. Total maximum daily load implementation
plan for Black Creek and Deer Creek, St. Louis County and St. Louis City. Pollutants of concern: Pathogens. 27pp.
MSD & MS4 Co-permittees
Black Creek and Deer Creek E. coli TMDL ARAP
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identified as WBID 3826 is approximately 1.6 miles in length and is listed as Class P water 3. WBID 3826
has been assigned the following designated uses: Livestock and Wildlife Protection; Irrigation;
Protection and Propagation of Fish, Shellfish, and Wildlife – Warm Water Habitat; Human Health
Protection; Secondary Contact Recreation; and, Whole Body Contact Recreation Category A. Black
Creek is a tributary to Deer Creek and its drainage area is nested within the northeastern portion of Deer
Creek watershed. Black Creek begins in south Olivette and flows southward for approximately 5.6 miles
to its mouth at Deer Creek. This reach includes the impaired segment, WBID 3825, and is also listed as
Class P water3. WBID 3825 has been assigned the following designated uses: Livestock and Wildlife
Protection; Irrigation; Protection and Propagation of Fish, Shellfish, and Wildlife – Warm Water Habitat;
Human Health Protection; Secondary Contact Recreation; and, Whole Body Contact Recreation Category
B. As described in the Black Creek and Deer Creek E. coli TMDL, each stream reach impaired by
bacteria is shown in Figure 1.
Deer Creek watershed covers approximately 36.5 square miles and is comprised of karst geology,
including a single gaining stream segment approximately 5.05 miles in length from Interstate 64 to the
confluence with Black Creek. The Deer Creek watershed includes portions of the following MS4 co-
permittees: St. Louis County (unincorporated areas); Brentwood; Clayton; Creve Coeur; Des Peres;
Frontenac; Glendale; Kirkwood; Ladue; Olivette; Richmond Heights; Rock Hill; Shrewsbury; Town and
Country; University City; Warson Woods; and, Webster Groves.
3 Missouri’s Water Quality Standards at 10 CSR 20-7.031 Table H. March 31, 2018.
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Black Creek and Deer Creek E. coli TMDL ARAP
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A TMDL is a calculation that sets the amount of pollutant a water body can assimilate without exceeding
the water quality criterion for that particular pollutant. The TMDL allocates the pollutant load among
three components:
1) Wasteload allocation (WLA) for all point sources and MS4 Operators;
2) Load allocation (LA) for all nonpoint sources and natural background sources; and,
3) Margin of Safety (MOS) to account for any uncertainty in data or model assumptions.
The TMDL is equal to the sum of the wasteload allocation, load allocation, and margin of safety as
expressed in the following equation:
TMDL = ΣWLA + ΣLA + MOS
The Black Creek and Deer Creek E. coli TMDL was developed using numeric target concentrations of
206 counts/100mL for Black Creek and 126 counts/100mL for Deer Creek, and a load duration curve for
each waterbody. Both numeric target concentrations represent Missouri’s water quality criteria for Whole
Body Contact Recreation Categories A and B. The load duration curve for Black Creek applied average
daily discharge data (cfs) from May 19, 2004 to December 28, 2016 from the United States Geological
Survey (USGS) gage station 07010082 near Brentwood, MO. The load duration curve for Deer Creek
applied average daily discharge data (cfs) from March 23, 2004 to December 28, 2016 from the USGS
gage station 07010086 at Maplewood, MO. Discharge data were corrected according to the ratio of the
impaired drainage area, as delineated by its outlet, to the gage drainage area. The numeric target
concentration was multiplied by the corrected average daily discharge and a conversion factor to calculate
the daily load (counts/day) at specific discharges.
Regulation of stormwater discharges from systems owned or operated by MS4s in Black Creek and Deer
Creek watersheds is covered under two MS4 permits. The first MS4 permit is held by MSD and its 60
co-permittees (referred to as MSD MS4 permit from hereon) and covers a jurisdiction of approximately
96.1 percent of the watershed. The second is a site specific MS4 permit held by the Missouri Department
of Transportation (Permit No. MO-0137910) and covers the remaining 3.9 percent. There are no other
permitted facilities in Black Creek and Deer Creek watersheds that might reasonably contribute to
bacteria loading, thus all of the WLA was assigned to the MS4 area. Furthermore, since it was not
possible to accurately disaggregate E. coli loading for each MS4, the WLA was assigned as an aggregate
wasteload to the total MS4 area. Please see Tables 1 and 2, adapted from the Black Creek and Deer
Creek E. coli TMDL1.
Table 1. TMDL requirements for E. coli bacteria at specific flows in Black Creek (WBID 3825)1.
Percentile Flow
Exceedance
Flow
(cfs)
TMDL
(counts/day)
MS4 WLA
(counts/day)
LA
(counts/day)
95 0.43 2.16E+09 2.16E+09 0
75 0.88 4.46E+09 4.46E+09 0
50 1.64 8.29E+09 8.29E+09 0
25 4.37 2.20E+10 2.20E+10 0
10 18.31 9.23E+10 9.23E+10 0
cfs =cubic feet per second; WLA = wasteload allocation; LA = load allocation
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Black Creek and Deer Creek E. coli TMDL ARAP
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Table 2. TMDL requirements for E. coli bacteria at specific flows in Deer Creek (WBID 3826)1.
Percentile Flow
Exceedance
Flow
(cfs)
TMDL
(counts/day)
MS4 WLA
(counts/day)
LA
(counts/day)
95 0.58 1.80E+09 1.80E+09 0
75 1.26 3.88E+09 3.88E+09 0
50 2.78 8.58E+09 8.58E+09 0
25 11.49 3.54E+10 3.54E+10 0
10 70.21 2.16E+11 2.16E+11 0
cfs =cubic feet per second; WLA = wasteload allocation; LA = load allocation
While on-site wastewater treatment systems are noted in the TMDL as a potential nonpoint source, they
are not expected to contribute to the bacteria impairment if properly functioning and were assigned a load
allocation of zero. In addition, the catchments that contribute stormwater runoff to the outfalls permitted
under the MSD MS4 permit were not identified during development of the TMDL. Therefore, the
nonpoint source load allocation (LA) was not disaggregated from the MS4 WLA and no load allocations
were assigned in the Black Creek and Deer Creek E. coli TMDL.
The margin of safety component is considered implicit because of conservative assumptions used in the
TMDL model, the use of multiple years of stream discharge data collected under a complete range of
conditions, reduced uncertainty of the sources of the bacteria impairment and remediation of bacteria
sources through MSD’s Project Clear program. In addition, the daily load estimated values used the
recreation-season geometric mean while at the same time omitting bacteria decay rates, which are
overlapping conservative assumptions.
1.2 MS4 Permit Requirements
Missouri General Operating Permit MOR040005 (issued on November 1, 2021), Section 6.1.A requires
any regulated MS4 identified in an EPA approved or established TMDL with an applicable WLA shall
implement steps towards the attainment of applicable WLAs in accordance with 40 CFR 122.44(k)(2) and
(3). Section 6.1.B of the permit states the permittee shall develop a TMDL ARAP to address the TMDL’s
assumptions and requirements where applicable. The TMDL ARAP shall be incorporated into the
Stormwater Management Program (SWMP ) and include, at a minimum, the following:
6.1.C (1) A plan to identify potential sources of the pollutant(s); (2) a plan to implement BMPs to
address the sources within the MS4 area; and, (3) a schedule, including beginning and ending
milestones, which are expressed as month and year to implement planned BMPs. The schedule
for the implementation of the TMDL ARAP shall be completed as soon as practicable, but is not
limited to the five year term of this operating permit as attainment can take years or even multiple
permit terms.
6.1.D BMPs shall be developed or designed with a purpose of reducing the pollutant(s) of concern. The
ARAP shall list each BMP and shall contain a description of the BMP, the purpose of the BMP,
and the expected result of the BMP.
6.1.E Measurable goals shall be established for each BMP or in conjunction with multiple BMPs. (1)
Each measurable goal shall contain a statement clearly indicating how it will be established to
determine the appropriateness of identified BMPs and progress toward the expected results of the
BMP. (2) Measurable goals shall be quantifiable; however, if it is not feasible to utilize a
measurable goal that is quantifiable, then the permittee shall provide justification indicating why
the measurable goal cannot be quantifiable. (3) If applicable, measurable goals shall also utilize
interim and completion milestone dates, and a periodic frequency of measurement to document
progress. Interim and final milestone dates shall be established with a format of month and year,
or as 1st, 2nd, 3rd, 4th, and 5th year of the operating permit cycle.
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6.1.F An iterative process shall be utilized by the permittee documenting how each BMP is evaluated
and subject to replacement or modification. The permittee shall apply reasonable further progress
by replacing or modifying ineffective BMPs with effective BMPs.
2.0 E. coli Bacteria and its Potential Sources
E. coli bacteria commonly inhabit the intestines of warm-blooded animals and their feces. In-stream
contributions of E. coli usually originate from humans, pets, livestock, and wildlife. There are a variety
of pathways E. coli might enter a waterway, such as stormwater runoff from agriculture and urban lands,
failing septic systems and illicit connections, and discharges from sewage infrastructure related to
wastewater treatment. The presence of E. coli measured at high concentrations indicates contamination
by fecal matter. While the broad group of E. coli bacteria are mostly considered harmless, its presence is
used an indicator of other pathogenic bacteria, viruses, and other microorganisms. Diseases from those
pathogens can cause eye, ear, nose, throat, and respiratory infections, as well as gastrointestinal illness.
Missouri’s Section 303d lists of impaired waters from 2012-2018 note the source of E. coli bacteria in
Black Creek and Deer Creek as urban runoff/storm sewers. The Black Creek and Deer Creek E. coli
TMDL describes several specific sources of E. coli bacteria including the sanitary sewer system, onsite
wastewater treatment systems (referred to herein as individual sewage disposal systems), urban
stormwater runoff, riparian corridor conditions, and to a lesser extent, stabled horses (backyard livestock)
and straight pipe illicit discharges. In particular, human sources of pathogens (e.g., sanitary sewer
discharges and onsite systems) are considered a higher human health risk depending upon the duration
and type of exposure. The following information is a summary of all potential sources of bacteria to
Black Creek and Deer Creek.
2.1 Sanitary Sewer Infrastructure
There are no permitted facilities that discharge domestic or municipal wastewater treatment systems in the
Deer and Black Creek watersheds. MSD’s Lemay Wastewater Treatment Plant which receives
wastewater generated in the Deer and Black Creek watersheds is located approximately 5.2 miles to the
southeast of Deer Creek’s confluence with the River des Peres. Sanitary sewer infrastructure is present
throughout the watershed however, comprising approximately 575 miles of pipe. A summary of public
sanitary sewer pipes found in the watershed is provided in Table 3, and a summary of sewer pipes that
have received rehabilitation (e.g. cured-in-place lining or sprayed liner) is presented in Table 4.
MSD & MS4 Co-permittees
Black Creek and Deer Creek E. coli TMDL ARAP
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Table 3. Summary of Sanitary Sewer Gravity Pipes by Pipe Diameter and Material in the Black Creek
and Deer Creek Watersheds as of August 13, 2021.
Pipe
Diameter
(inches)
VCP Plastic RCP Cast Iron
or DIP
CP
Block Other Sub-Total
-- Length in Feet
4 229 -- -- 143 -- -- -- 372
6 47,538 17,633 325 557 2,106 -- 109 68,267
8 864,321 1,176,857 1,007 5,481 6,035 -- 63 2,053,764
9 4,801 74,379 -- -- -- -- -- 79,180
10 67,246 99,234 915 1,662 1,566 -- 103 170,726
12 92,989 121,074 5,449 2,362 -- -- 2,875 224,749
14 -- 476 -- -- -- -- -- 476
15 24,277 58,668 2,389 849 -- -- 769 86,952
16 -- 1,933 -- 1,666 -- -- -- 3,599
18 38,390 43,746 2,661 1,402 -- -- 288 86,488
20 -- -- -- 64 -- -- -- 64
21 16,048 37,169 3,054 766 -- -- -- 57,037
22 58 -- -- -- -- -- -- 58
24 16,523 19,895 14,310 1,101 -- -- 422 52,251
27 7,147 8,373 2,883 61 -- -- -- 18,463
30 8,495 13,468 4,210 776 -- 324 192 27,466
33 1,992 2,705 181 -- -- -- -- 4,879
36 7,073 5,694 13,410 169 643 1,343 283 28,615
40 -- 658 -- -- -- -- -- 658
42 1,650 5,995 20,789 301 2,817 -- 31,553
48 881 281 8,028 49 829 3,874 -- 13,942
51 -- -- 191 -- -- 147 -- 338
54 -- 830 2,267 -- 560 -- -- 3,658
57 -- -- -- -- -- 21 -- 21
58 -- -- 180 -- -- -- -- 180
60 -- 402 962 -- 1,417 -- 111 2,892
63
-- -- -- -- 464 -- -- 464
64 -- -- -- -- -- 71 -- 71
72 384 3,026 1,841 -- -- -- 49 5,300
78 -- 228 392 306 3,070 483 16 4,494
84 -- -- 7,409 -- 384 -- -- 7,793
88 -- 53 -- -- -- -- -- 53
90 -- 428 1,315 -- -- -- -- 1,743
96 -- -- 385 -- -- -- -- 385
120 -- 1,232 -- -- -- -- 1,232
Total 1,200,044 1,693,207 95,786 17,715 17,073 9,079 5,281 3,038,185
VCP is vitrified clay pipe; RCP is reinforced concrete pipe; DIP is ductile iron pipe; CP is concrete pipe.
MSD & MS4 Co-permittees
Black Creek and Deer Creek E. coli TMDL ARAP
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Table 4. Summary of Sanitary Sewer Pipes by Pipe Diameter and Material that have
Received Rehabilitation in the Black Creek and Deer Creek Watersheds
as of August 13, 2021.
Pipe
Diameter
(inches)
VCP PVC RCP Cast
Iron DIP
CP Other Sub-Total
-- Length in Feet
6 8,985 163 -- -- -- 962 122 10,233
8 897,768 9,209 577 1,677 1,291 30,887 1,493 942,902
9 74,158 221 -- -- -- -- -- 74,379
10 75,576 1,904 238 287 66 4,018 170 82,259
12 80,241 2,177 3,301 332 399 1,121 187 87,757
15 30,762 623 745 21 118 -- -- 32,270
16 -- -- 84 -- 559 -- -- 642
18 19,189 316 29 333 323 -- 144 20,334
21 20,066 498 4,321 493 -- -- -- 25,378
24 7,844 -- 4,439 -- -- -- 225 12,509
27 5,513 -- 1,687 -- -- -- 1,172 8,373
30 9,016 -- 2,441 -- -- -- 511 11,968
33 2,705 -- -- -- -- -- -- 2,705
36 1,257 -- 2,994 -- 1,443 -- -- 5,694
40 -- -- -- -- -- -- 658 658
42 95 -- 5,256 -- -- -- 644 5,995
48 -- -- -- -- -- -- 281 281
88 -- -- -- -- -- -- 53 53
90 -- -- -- -- -- -- 428 428
Total 1,233,175 15,112 26,113 3,143 4,199 36,989 6,087 1,324,818
VCP is vitrified clay pipe; PVC is polyvinyl chloride; RCP is reinforced concrete pipe; DIP is ductile iron pipe;
CP is concrete pipe.
In addition to sewer pipes, there are 15,269 sanitary manholes in the Black Creek and Deer Creek
watersheds that fall under public or private ownership. Manholes are mostly constructed of brick, cast-in-
place concrete, precast sections of concrete and other materials. MSD does not own or operate any
sanitary pump stations in the watershed; however, there are three pump stations located outside the
watershed which convey sewage to sanitary sewers located within Deer Creek watershed (Windmoor (P-
710), Ballas Meadows (P-712), and Horton Place (P-814)).
Of the 45 constructed sanitary sewer overflow (SSO) points first described in the TMDL, there are 26 that
remain as of November 8, 2021. Of these 26 constructed SSO outfalls, 14 are located in Black Creek
watershed. Per MSD’s Project Clear Program, seven (7) active constructed SSO outfalls are scheduled for
elimination prior to 2024, another 10 are scheduled for removal between 2024-2028, and nine (9) are
scheduled to be removed between 2029-2033.
Unintended overflows from the sanitary system however may still occur from time to time as a result of
blockages, line breaks, power failures and vandalism. A summary of dry weather capacity and non-
capacity overflows and bypasses that reached a receiving stream in the Black Creek and Deer Creek
watersheds for the period of January 1, 2018 through December 31, 2020 is provided in Table 5.
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Table 5. Summary of Capacity and Non-Capacity Overflows and
Bypasses for Black Creek and Deer Creek Watersheds,
01/01/2018 - 12/31/2020.
Cause Count Remedy
Debris Blockage 18 Cleaned/Cleared, Repaired
Root Blockage 4 Cleaned/Cleared
Grit Blockage 3 Cleaned/Cleared
Grease Blockage 3 Cleaned/Cleared
Broken Pipe 5 Repaired
Total 33 --
As part of the SSO Master Plan requirement in MSD’s federal consent decree 4, MSD conducted a Sewer
System Evaluation Survey (SSES) for the Deer and Black Creek watersheds. SSES findings related to
sewer defects are described in Section 3.2.1.1 of this ARAP, and SSO Master Plan remedial projects are
described in Section 3.2.1.2 and Appendix A.
2.2 Individual Sewage Disposal Systems
Individual sewage disposal systems are considered nonpoint sources of pollution. Failing systems are
known sources of bacteria that can enter nearby streams through surface and subsurface flows. As
referenced in the Black Creek and Deer Creek E. coli TMDL, a study conducted by the Electric Power
Research Institute (EPRI) suggests that up to 50 percent of these systems in Missouri may be failing5.
In a recent survey conducted specifically for MSD to gather information on environmental awareness in
MSD’s service area, out of 570 residents contacted by either mail or online, 4% (22) indicated they had a
septic system at their home6. When residents were asked if their septic system had been serviced in the
last five years, 64% (14) of those indicated it had, 14% (3) said it had not, and 23% (5) were unsure6. Of
18 residents asked about the age of their system, 28% (5) said their septic system was more than 30 years
old6.
The prevalence of individual sewage disposal systems in the Black Creek and Deer Creek watersheds has
been reduced over time. According to MSD Rules and Regulations, treatment using a septic system is not
allowed when public sanitary sewers are within 200 feet of any point on a property and determined to be
available, or when a lot is less than three (3) acres in size. Still, there are approximately 30 parcels in the
Black Creek and Deer Creek watersheds combined which are suspected of not having a connection to the
public sewer1. Non-sewered parcels include those with structures and those without, though it is not
directly known how many parcels with existing structures have an individual sewage disposal system in
operation. Therefore contributions of bacteria from failing individual sewage disposal systems are likely,
however the scope of the problem within Black Creek and Deer Creek watersheds is not entirely known.
4 United States of America and the State of Missouri, and the Missouri Coalition for the Environment Foundation v. Metropolitan
St. Louis Sewer District, No. 4:07-CV-1120.
5 Electric Power Research Institute. 2000. Advanced On-Site Wastewater Treatment and Management Market Study: Volume 2:
State Reports. TR-114870. 224pp.
6 ETC Institute for Metropolitan St. Louis Sewer District. 2017. Metropolitan St. Louis Sewer District environmental awareness
survey. ETC Institute. 47pp.
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2.3 Agricultural Runoff (Stabled Horses)
While agricultural land use is not present in Black Creek and Deer Creek watersheds, some properties in
the City of Huntleigh (a non-MS4 co-permittee) include stabled horses on site1. The City of Huntleigh is
entirely located within Deer Creek watershed and is drained by Two Mile Creek and other tributary
streams. It is feasible that stormwater runoff contaminated with E.coli bacteria could reach Two Mile
Creek or other tributary streams if manure is not properly managed.
2.4 Urban Stormwater Runoff
Urban stormwater runoff is known to contain high levels of bacteria and is another potential contributor
of E. coli to Black Creek and Deer Creek. According to a study conducted by USGS 7 median E. coli
densities from six stream locations in MSD’s service area were strongly correlated with the percentage of
upstream impervious cover. Runoff from both pervious and impervious areas has the potential to pick up
and transport bacteria from domestic and wild animal waste. Pet waste may enter local waterways from
residential areas, as well as areas open to the public, such as dog parks, parks, trails, or other recreational
areas utilized by pet owners. Wild animals like raccoons inhabiting the storm system or nuisance geese
residing on local ponds are also potential sources. Additionally, bird droppings on roadways can easily
be carried into the storm system and transported to streams during rain events. Waste from livestock,
poultry, pets, and wildlife are all known to contribute to E. coli concentrations in urban streams. On
average, 10 percent of E. coli in six metropolitan St. Louis streams was traced to dogs and another 20
percent to geese8. Note, this USGS7 study included data from adjacent drainages, but not Black Creek or
Deer Creek watersheds.
Urban runoff discharges from the two MS4 permitted systems are considered potential point sources of E.
coli to Black Creek and Deer Creek. As previously discussed, the catchments that contribute stormwater
runoff to the outfalls permitted under the MSD MS4 permit were not identified during development of the
TMDL. Stormwater runoff from areas not served by the MS4s is considered a nonpoint source.
However, the nonpoint source load allocation (LA) was not disaggregated from the MS4 WLA and no
load allocations were assigned in the Black Creek (WBID 3825) and Deer Creek (WBID 3826) E.coli
TMDLs, respectively.
2.5 Riparian Conditions
Riparian corridor conditions in the watershed were listed in the Black Creek and Deer Creek E. coli
TMDL as a likely source of bacteria. The riparian corridor of streams in the Deer Creek watershed,
extending 30-meters on each side of the channel, consists mostly of land cover types containing various
degrees of development and imperviousness1. Notably, more than 52 percent of the riparian corridor in
this watershed is categorized as having low to high intensity development and greater than 20 percent
impervious coverage1. Open space development, land containing less than 20 percent impervious cover,
makes up approximately 47 percent of the riparian corridor1. Riparian areas comprised of low to high
intensity development or even open space development are potential sources of bacteria when stormwater
runoff comes in contact with pet and wildlife wastes.
2.6 Illicit Straight Pipe Discharges
Illicit straight pipe discharges occur where household waste is discharged directly to a stream or area of
land, and are different from illicitly connected sewers. Due to the presence of a sewerage system
throughout the Black Creek and Deer Creek watersheds, illicit straight pipe discharges are not expected to
be significant contributors of E. coli. However, there is potential for private sewer laterals to fail on
occasion and discharge sewage to waterways. Illicit discharges such as these have been found across
7 Wilkison, D.H., Davis, J.V. 2010. Occurrence and sources of Eschericia coli in metropolitan St. Louis streams, October 2004
through September 2007: U.S. Geological Survey Scientific Investigations Report 2010-5150. 57pp.
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MSD’s service area through Illicit Discharge Detection and Elimination work as required under Minimum
Control Measure #3 of the MS4 permit. Discharges from failed sewer laterals are resolved by the
homeowner, usually with partial funding assistance from a local lateral repair program.
3.0 TMDL Implementation Activities
The implementation of activities provided in this ARAP will aim to reduce bacteria loading in Black
Creek and Deer Creek. In large part, those activities will be implemented through ongoing programs
already being executed. The two main implementing programs are the St. Louis County Phase II
Stormwater Management Plan (Fourth Term Permit 2021-2026) and MSD’s consent decree obligations,
established as part of the United States of America and the State of Missouri, and the Missouri Coalition
for the Environment Foundation v. Metropolitan St. Louis Sewer District, No. 4:07-CV-1120. Additional
activities beyond these two programs will harness information generated through existing MSD
maintenance operations with the goal of developing and implementing further bacterial reduction.
3.1 St. Louis County Phase II Stormwater Management Plan
The St. Louis County Phase II Stormwater Management Plan (Fourth Term Permit 2021-2026), referred
to herein as the Stormwater Management Plan (SWMP), was developed in compliance with the MS4
permit issued to MSD and its co-permittees. The permit requires MS4s, MSD and its co-permittees, to
implement activities via an iterative process to reduce the discharge of pollutants to the maximum extent
practicable (MEP) into the MS4 for the goal of attainment with Missouri’s Water Quality Standards. The
SWMP, which was approved by MDNR on August 26, 2021 contains six minimum control measures
(MCM) that include measurable activities for addressing requirements under Part 4 of the MS4 permit.
Goals for each activity are set in each year of the permit, and annual reports are submitted to MDNR
regarding the status of each goal. Goals are reviewed annually and the SWMP may be updated as needed
or following renewal of the MS4 permit.
Continued implementation of the SWMP through the iterative evaluation process will result in a
significant reduction of pollutants discharged to waters in the plan area, including the discharge of E. coli
bacteria to Black Creek and Deer Creek. The result of implementing each activity will be reported
through the SWMP annual reporting process.
The following is a summary of SWMP activities expected to reduce bacteria contributions to Black Creek
and Deer Creek. Each activity references its corresponding goal in the SWMP. Prioritization activities,
measurable goals and milestones, implementation schedules, and the iterative evaluation process for the
activities described below will be consistent with those already identified in the SWMP. The strategy for
evaluating the effectiveness of the SWMP is based upon assessing three key performance characteristics
including (1) Program Operations and Activities, (2) Social Indicators and (3) Water Quality Data
Analysis across each of the MCM activities. Please review the SWMP for a complete description of all
activities under each MCM along with their schedule for implementation8. All activities in the SWMP
shall be reviewed and evaluated for effectiveness annually to determine if they should be replaced or
modified.
3.1.1 MCM #1, Public Education and Outreach on Stormwater Impacts
MSD and its co-permittees are required to implement a public education program to distribute educational
material to the community and/or conduct equivalent outreach activities about the impacts of stormwater
discharges on waterbodies and the steps the public can take to reduce pollutants in stormwater runoff.
This program targets several pollutant sources that directly or indirectly address bacteria, including: pet
waste; yard management; individual sewage disposal systems; land disturbance; and fats, oils, and grease
(FOG). Under MCM#1, the current SWMP lists 23 individual activities that are intended to identify
8 The SWMP is available on MSD’s website, https://msdprojectclear.org/.
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entities that may have an impact on stormwater, identify target audiences to foster nonpoint source
pollution and water quality awareness, and ultimately increase awareness and positive behavior changes
for those in the community. Of those 23 activities, 17 pertain to bacterial reduction and are noted as
follows:
1. Query MSD Asset Management System for list of active food service and restaurant
establishment facilities (Goal 3 of SWMP). Active food service and restaurant facilities are
among the target audience for distributing educational materials containing information on
bacteria pollution and prevention.
2. Collect a stormwater education survey (Goal 6 of SWMP). The survey will allow MSD to
monitor trends in public water quality awareness in its service area, and will yield valuable
information about awareness for bacteria pollution.
3. Maintain a database of all K-12 public and private school districts in the plan area (Goal 7 of
SWMP). The database will be used to foster nonpoint source pollution and water quality
awareness in the community by identifying those schools which provide stormwater
education. Bacteria pollution prevention is a component of stormwater education.
4. Develop and distribute stormwater messages for MSD bills and websites (Goal 8 of SWMP).
Pet waste and individual sewage disposal systems are among the messaging topics.
5. Maintain and provide a library of stormwater education materials for the purpose of
providing brochures, flyers, and other media that can be used at public events and upon
request (Goal 9 of SWMP). Educational materials will include information on bacteria
pollution and prevention.
6. Provide presentations and educational materials to families and homeowners for the purpose
of fostering nonpoint source pollution and water quality awareness in the community (Goal
10 of SWMP). Presentations and educational materials will include information on bacteria
pollution and prevention.
7. Post pet waste signs in parks for the purpose of fostering nonpoint source pollution and
water quality awareness in the community (Goal 11 of SWMP). The effort will directly
address pet waste as a source of bacteria.
8. Maintain a database of community partners with water pollution education interests that can
work with MSD to foster nonpoint source pollution and water quality awareness for target
pollutants, including bacteria (Goal 12 of SWMP).
9. Provide educational materials to industrial entities, waste haulers, and food service and
restaurant establishments to foster nonpoint source pollution and water quality awareness in
the community (Goal 13 of SWMP). Presentations and education materials will include
information on bacteria pollution and prevention.
10. Provide presentations and educational materials to trade associations, schools, and watershed
groups to foster nonpoint source pollution and water quality awareness (Goal 14 of SWMP).
Presentations and education materials will include information on bacteria pollution and
prevention.
11. Partner with community organizations to provide stormwater information to a broad
audience to foster nonpoint source pollution and water quality awareness (Goal 15 of
SWMP). Stormwater information to cover bacteria pollution and prevention among the
target pollutants.
12. Advertise videos to be utilized in social media platforms in order to provide education to
broad audiences (Goal 16 of SWMP). Messaging to include information on bacteria
pollution and prevention.
13. Provide training to educators, watershed group members, and others on how to use the
Enviroscape® watershed models for the purpose of engaging citizen volunteers on how to
educate students on sources of pollution and best practices, providing additional resources
(Goal 19 of SWMP). Education and training will cover bacteria pollution and prevention.
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14. Provide Enviroscape® watershed models for community use for the purpose of fostering
nonpoint source pollution and water quality awareness (Goal 20 of SWMP). Education will
cover bacteria pollution and prevention.
15. Provide storm drain marker instructions and equipment to citizen volunteers for the purpose
of fostering nonpoint source pollution and water quality awareness (Goal 21 of SWMP).
Storm drain marking will address bacteria among other target pollutants.
16. Develop a storm drain marking GIS map to facilitate community opportunities to participate
in the storm drain marking program (Goal 22 of SWMP). Storm drain marking will address
bacteria among other target pollutants.
17. Provide resources, as available, to residential, institutional, and commercial landowners and
citizen volunteer organizations that promote green infrastructure and other healthy water
programming (Goal 23 of SWMP). Resources will foster nonpoint source pollution and
water quality awareness, and target stormwater pollutants including bacteria. In addition to
these efforts that are conducted within the framework of the MS4 SWMP and co-permittee
relationship, organizations such as the Deer Creek Watershed Alliance noted in the TMDL
Implementation Plan and other watershed stewards may also be implementing non-point
source water quality improvement strategies that are synergetic to the MS4 SWMP and this
TMDL ARAP.
3.1.2 MCM #2, Public Involvement/Participation in Program Development
Under MCM #2, MSD and its co-permittees implement a public involvement/participation program that
provides opportunities for the public in development and oversight of the SWMP, as well as opportunities
for involvement with the permittee’s renewal application. Collectively, there are six SWMP activities
that address MCM#2 requirements. Three of these activities have specific goals under MCM#2, whereas
the remaining three activities which are necessary to meet MS4 permit requirement 4.2.C (i.e. Goals 8, 31
and 46 of SWMP) are actually included under different MCMs and are described in their respective
sections of this report. Goals 8, 31 and 46 of the SWMP aim to reduce bacteria concentrations in
stormwater runoff and improve water quality.
3.1.3 MCM #3, Illicit Discharge Detection and Elimination
As part of MCM #3, MSD carries out an Illicit Discharge Detection and Elimination (IDDE) Program.
An illicit discharge is any discharge to the stormwater system that is not composed entirely of stormwater,
and may result from illegal dumping, a direct connection from the sanitary sewer to the storm sewer, or an
indirect connection from improper surface discharges to the storm sewer. Under this program, MSD
surveys channels in priority areas likely to have illicit discharges within the plan area at least once every
five years, inspects outfalls for illicit discharges, responds to reports of illegal dumping, and conducts
timely elimination of prohibited discharges. Priority areas for channel surveys are based on the history of
IDDE activities in the watershed, strategic databases (e.g. properties known or likely to utilize a septic
system), water quality impairments, established TMDLs, and approved TMDL ARAPs. In the past, staff
conducting illicit discharge surveys have discovered and eliminated illegal dumping of pet waste, leaking
sewer lines, and failing private sewer laterals and onsite septic systems. MSD’s implementation of the
IDDE program is expected to be one of the most impactful actions to improve water quality in Black
Creek and Deer Creek watersheds.
There are 15 activities implemented under MCM #3, all of which either target sources of bacteria directly
or facilitate the process of identifying and eliminating bacteria sources. Those activities are as follows:
1. Maintain a Geographic Information System (GIS) showing constructed MS4 outfalls and
receiving streams (Goal 27 of SWMP). This GIS is used to locate and view outfalls in the
plan area, and in the process identify and investigate sources of bacteria.
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2. Use map update work orders to track any modifications to the sewer map for the purpose of
maintaining current information on the storm sewer system in the plan area watersheds (Goal
28 of SWMP). This activity will improve the identification, tracking, and elimination of
potential sources of bacteria.
3. Enforce MSD ordinance No. 15048, and others as required (Goal 29 of SWMP). Ordinance
No. 15048 serves as MSD’s legal enforcement tool for eliminating prohibited discharges,
including those that may be a source of bacteria.
4. Survey Plan Area natural channels in 2020 303(d) impaired stream listing watersheds
(Excluding the Missouri River major watershed) identified on MSD’s basemap once every
five years (Goal 30 of SWMP). This activity will lead to detecting and eliminating illicit
discharges, including those that are a source of bacteria.
5. Respond to reports of illegal dumping, which will include detecting and eliminating sources
of bacteria (Goal 31 of SWMP).
6. Maintain operating procedures for tracing illicit discharges from the public sewer system
(Goal 32 of SWMP). The purpose is to provide for timely and efficient illicit source
identification, including sources of bacteria.
7. Maintain operating procedures for eliminating illicit discharges (Goal 33 of SWMP). The
purpose is to provide for timely and efficient illicit source elimination, including sources of
bacteria.
8. Provide public outreach communications tools (e.g. brochures, etc.) to sources of non-
stormwater discharge that could be substantial contributors of pollutants into the MS4, such
as street cleaning, residential car washing, and residential swimming pools (Goal 34 of
SWMP). The purpose is to foster stormwater nonpoint source pollution awareness and
behavior change in the community and some of the communication tools will include
information about bacteria.
9. Maintain and distribute brochures, door hangers, and other communication tools that inform
about hazards associated with illegal discharges and improper disposal of waste (Goal 35 of
SWMP). This activity will foster stormwater nonpoint source pollution awareness and
behavior change in the community and some of the materials will include information on
bacteria.
10. Maintain operating procedures for field testing and surveying to help identify chemicals
indicative of illicit discharges for the purpose of timely and efficient illicit source
identification and elimination, including those that are a source of bacteria (Goal 36 of
SWMP).
11. Maintain and annually review findings from channel surveys, and inspect previous findings
(Goal 37 of SWMP). The purpose of this activity is to identify priority areas for potential
monitoring and follow-up, including those that may be sources of bacteria.
12. Review representative water quality data collected by MSD to prioritize investigation areas
and identify potential source areas, including those that may be contributors of bacteria (Goal
38 of SWMP).
13. Survey individual sewage disposal systems (i.e., septic tanks) in Plan Area watersheds
containing streams on the 2020 303(d) list (excluding Missouri River, Goal 39 of SWMP).
Detect and eliminate illicit discharges that are sources of bacteria.
14. Develop a tabular database and GIS layer of properties that have participated in a sewer
lateral repair program in order to assist with illicit discharge investigations (Goal 40 of
SWMP). This activity directly pertains to bacteria as a pollutant.
15. Maintain an enforcement plan for addressing illicit discharges in order to secure timely
elimination of illicit discharges, including those that are sources of bacteria (Goal 41 of
SWMP).
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Please note, information gathered for goals 38, 39, and 40 of the SWMP will also be used to support
bacteria reduction strategies listed in Section 3.3 TMDL Best Management Practices Targeting Bacteria.
3.1.4 MCM #4, Construction Site Stormwater Runoff Control
Under MCM #4, MSD and its co-permittees develop, implement, and enforce a program to reduce
pollutants in any stormwater runoff to their regulated Small MS4 from construction activities that result in
land disturbances greater than or equal to one acre. Reduction of stormwater discharges from a
construction activity disturbing less than one acre is included in the program if that construction activity is
part of a larger common plan of development or sale that would disturb one acre or more.
Each incorporated municipality has the authority for construction permitting and inspection services.
Some co-permittees provide full permitting and inspection services independently, while others have
adopted St. Louis County’s ordinance and contract with St. Louis County Code Enforcement to meet
permitting and inspection needs. While bacteria contributions from land disturbance sites is expected to
be low, the potential for discharges of E. coli from sanitary facilities at construction sites is reduced
through inspections and enforcement. There are eight individual activities implemented under MCM #4,
of which five specifically relate to bacteria through retaining waste on site or by ensuring sediment and
erosion controls are properly installed. Those five activities are as follows:
1. Maintain written procedures and guidance materials for operators to follow (Goal 44 of
SWMP). This activity will help prevent sanitary waste from leaving the site and potentially
entering a water course.
2. Maintain written procedures and guidance materials for permittees to follow (Goal 45 of
SWMP). This activity will address bacteria by requiring development pre-construction
planning and appropriate installation and maintenance of sanitary waste facilities.
3. Maintain written procedures to receive, respond to, and track public inquiries and complaints
(Goal 46 of SWMP). This activity will address bacteria by providing timely responses to
complaints of sanitary waste leaving a site.
4. Maintain written procedures and checklists for permittees to follow during SWPPP
inspections (Goal 47 of SWMP). This activity will address bacteria by ensuring BMPs for
sanitary waste facilities are properly installed and maintained.
5. Inspect land disturbance sites per land disturbance program ordinance (Goal 48 of SWMP).
This activity will address bacteria by ensuring BMPs for sanitary waste facilities are properly
installed and maintained.
3.1.5 MCM #5, Post-Construction Stormwater Management in New Development and
Redevelopment
MSD and its co-permittees require developers to implement appropriate strategies and controls to address
post-construction runoff from new development and redevelopment projects that disturb one acre of land
or more, including projects less than one acre that are part of a larger common plan of development or
sale. MSD and co-permittee ordinances ensure all applicable public and private development projects
involving stormwater management are reviewed and approved by MSD.
All projects are required to assess existing site conditions and identify sensitive areas and natural
resources on site. The Rules and Regulations require that site designers prepare a site development plan
that adequately protects sensitive areas and natural resources and does not generate unwarranted amounts
of stormwater pollution. This plan may be based on the current version of the Site Design Guidance
document on MSD’s website. Development sites regulated in the MS4 are required to apply strategies
that reasonably mimic predevelopment runoff conditions by reducing runoff volume to calculated
predevelopment levels. MSD requires all stormwater facilities to be provided and designed in accordance
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with provisions contained in the “Rules and Regulations and Engineering Design Requirements for
Sanitary Sewer and Stormwater Drainage Facilities,” as amended.
The Bacteria and Nutrient Best Management Practice Strategy Review, conducted by Geosyntec
Consultants and reported in a memorandum dated December 23, 2016 (Appendix B), evaluated MSD’s
ongoing stormwater management facility selection based on bacteria and nutrient reduction effectiveness
and helped characterize BMP implementation to the MEP. This review found that nearly 70% of built or
planned structural facilities in the MS4 area scored high for removal of bacteria. Those structural
facilities included bioretention basins, infiltration facilities, permeable pavements, and ponds. Continued
implementation of these stormwater facilities and enhancements as recommended in the memorandum
will help meet bacteria reduction targets.
Maintenance responsibility for approved post-construction stormwater management facilities belongs to
the owner. MSD’s authority to ensure stormwater facilities are maintained is covered under MSD
Ordinance No. 15048. Owners submit annual reports on facility condition and MSD conducts inspections
of each stormwater facility at least once every three years.
There are eight activities implemented under MCM #5 in the current SWMP, all of which will help to
reduce bacteria contamination of stormwater. Those activities are as follows:
1. Utilize the technology matrix in MSD’s stormwater management toolbox and maintain
existing strategies (Goal 50 of SWMP). This activity will require developments to implement
appropriate strategies and controls to address post-construction runoff, and will result in
implementing activities to the MEP, including those that target bacteria.
2. Identify co-permittees who have implemented supplemental practices to reduce impervious
parking areas and incorporate green infrastructure (Goal 51 of SWMP). This activity will
reduce impervious parking areas and reduce barriers to incorporating green infrastructure into
parking areas, helping to remove bacteria stormwater.
3. Maintain an optional conceptual review process to provide developers with a plan review
assessment of appropriate strategies and controls to address post-construction runoff (Goal 52
of SWMP). This activity will identify opportunities for water quality protection, including
identifying stormwater facilities that can help remove bacteria early in the project planning
phase.
4. Make the Site Design Guidance document available to provide developers and plan reviewers
a way to implement effective stormwater management controls (Goal 53 of SWMP). This
activity will lead to utilizing effective stormwater facilities, protecting sensitive areas, and
help to remove bacteria from stormwater.
5. Use pre-condition assessment with early stage project planning which will lead to utilizing
effective stormwater facilities, protecting sensitive areas, and help to remove bacteria from
stormwater (Goal 54 of SWMP).
6. Follow MSD and co-permittee ordinances, as well as MSD Rules and Regulations, which
require developers and plan reviewers to implement appropriate strategies and controls to
address post-construction runoff (Goal 55 of SWMP). Included among those strategies and
controls, is the use of certain stormwater management facilities that remove bacteria from
stormwater.
7. Follow the plan review process of executing maintenance agreements for the environmental
compliance inspection process in order to ensure long-term operation of stormwater facilities,
including those that remove bacteria (Goal 56 of SWMP).
8. Inspect all water quality stormwater facilities utilizing key performance indicators to
demonstrate compliance (Goal 57 of SWMP). This activity will ensure the long-term
operation of stormwater facilities, including those that remove bacteria from stormwater.
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3.1.6 MCM #6, Pollution Prevention/Good Housekeeping for Municipal Operations
Under MCM #6, MSD and its co-permittees implement an operation and maintenance program that
includes a training component and has the ultimate goal of preventing or reducing pollutant runoff from
municipal operations. Common municipal operations that are addressed by an Operations and
Maintenance Program include: general housekeeping and operation and maintenance; vehicle/equipment
repair and maintenance operations; vehicle/equipment washing; facility repair, remodeling, and
construction; cleaning and maintenance of roadways, highways, bridges, and parking facilities;
maintenance of parks, green spaces, trails, and landscaping; cleaning and maintenance of drainage
channels, storm sewers, and inlet structures; operation and maintenance of recycling facilities; and, water
quality impact assessment of flood management projects. Written Operation and Maintenance Program
procedures help to ensure pollution controls are properly installed and maintained. Training provided to
staff covers pollution prevention and control techniques that may apply to the municipal operations noted
above, as well as identifying and reporting illicit discharges. There are 12 specific activities included
under MCM #6 in the SWMP, and eight of those help to reduce bacteria in stormwater. Those activities
are as follows:
1. Provide annual training to all MSD and co-permittee employees who work in municipal
operations impacted by stormwater in order to prevent and reduce stormwater pollution from
municipal operations (Goal 58 of SWMP). Training includes information on reporting illicit
discharges such as failing septic systems, which will help to reduce bacteria in stormwater.
2. Install stormwater facilities with the construction of municipal buildings and roadways,
where feasible, for the purpose of providing pollutant controls (Goal 60 of SWMP). Certain
facilities will help remove bacteria from stormwater.
3. MSD and all co-permittees are to maintain a written Operation and Maintenance Program to
ensure stormwater pollution prevention and control methods for municipal operations are
properly installed and maintained (Goal 63 of SWMP). The written Operation and
Maintenance Program template recommends certain activities that address bacteria (e.g.
posting pet waste signs in public parks and maintaining disposal stations, and developing and
enforcing ordinances against illicit discharges) be implemented to the maximum extent
practicable, in order to reduce levels of bacteria generated on property owned and operated by
the co-permittee.
4. MSD and all co-permittees are to maintain a written Operation and Maintenance Program to
prevent and reduce runoff from municipal operations (Goal s 65, 66 and 67 of SWMP). The
written program includes guidelines for posting pet waste signs in public parks, control of
wild geese populations near lakes, stormwater practices for improving the water quality of
site drainage, etc.), which will help to reduce bacteria in stormwater.
5. Maintain written guidelines for MSD to follow when preparing preliminary engineering
project studies for assessing water quality impacts for new flood management projects (Goal
68 of SWMP). MSD’s guidelines include recommendations for protecting and improving
water quality conditions, which will help reduce bacteria in stormwater.
6. Maintain written Operation and Maintenance Program to assess and mitigate water quality
impacts for new flood management projects (Goal 69 of SWMP). The written Operation and
Maintenance Program template includes recommendations for protecting and improving
water quality conditions, which will help reduce bacteria in stormwater.
3.2 Project Clear
MSD’s implementation of Project Clear has and will continue to result in reduced bacteria loading to
Black Creek and Deer Creek. Project Clear is a long-term effort by the Metropolitan St. Louis Sewer
District (MSD) that focuses on three categories of work: get the rain out; repair and maintain; and
building system improvements. Get the rain out focuses on preventing excess stormwater from entering
the sewer system through a variety of project types, including downspout disconnections, and
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rainscaping. Repair and maintain continues the work MSD has done to repair, maintain, and renew the
existing sewer system, on a faster timeline. Building system improvements involves new construction of
wastewater management structures, including deep underground tunnels and above-ground storage tanks.
Project Clear activities meet obligations required under the federal consent decree. Among those
obligations, MSD must eliminate all constructed sanitary sewer overflow outfalls no later than December
31, 20339. Other Project Clear strategies that involve sewer inspection, maintenance, and repair and
rehabilitation will reduce occurrences of sanitary sewer overflows as well. The following sections
describe MSD’s work under Project Clear and the federal consent decree that will address bacteria
loading in Black Creek and Deer Creek.
3.2.1 Sanitary Sewer Overflow Control Master Plan
MSD’s SSO Control Master Plan developed in compliance with the consent decree describes specific
measures that will result in the elimination of all constructed SSO outfalls, all known SSOs, building
backups, and/or that are necessary to ensure there is adequate capacity in the sanitary sewer system to
collect, convey, and treat anticipated wet weather flows under current and projected future conditions.
Remedial measures used to address capacity limitations and eliminate bypassing may include the removal
of I/I sources and increases in the capacities of sewer pipes, force mains, and pump stations. The SSO
Control Master Plan is required to eliminate 85% of the constructed SSO outfalls by December 31, 2023.
Elimination of up to 15% of the constructed SSO outfalls may occur after December 31, 2023, but all
must be eliminated no later than December 31, 2033.
3.2.1.1 Sewer System Evaluation Survey (SSES)
As part of the SSO Control Master Plan, MSD performed a SSES for the Black Creek and Deer Creek
watersheds 10. The purpose of the SSES was to identify 1) areas with excessive inflow/infiltration (I/I)
causing or contributing to SSOs and building backups, 2) known SSOs within the watershed, 3) physical
conditions and design constraints of pump stations and force mains that contribute to SSOs and building
backups, 4) physical and/or structural conditions of pipes, manholes, and structures in the sanitary sewer
system that contribute to SSOs and building backups, 5) sources of I/I determined to have excessive I/I
rates, and 6) stormwater cross connections and discovered unauthorized direct connections.
The SSES identified areas of the watershed with excessive I/I which were causing or contributing to SSOs
or building backups. That assessment was based on the following criteria: existence of constructed SSO
outfalls; number of sewer backup insurance claims; number of customer service requests; water quality
impacts; and, I/I rate estimates. The highest priority study areas in the Deer Creek watershed were most
prevalent in the eastern half of the watershed, generally overlapping with areas containing homes built
prior to 1940.
Physical/structural condition and design constraints of sanitary sewer infrastructure were also described in
the SSES report. The three operating pump stations previously mentioned in Section 2.1 Sanitary Sewer
Infrastructure were designed to mitigate wet weather issues. One pump station, Ballas Meadows (P-712)
does not have either backup storage capacity or on site back up power. During the period between April
27, 2007 and April 27, 2012, three sanitary sewer overflows were attributed to a pump station. During the
same time period there were no building backups attributed to pump stations. There were no design
constraints associated with any of the forcemains according to the SSES report. CCTV investigations of
6,568 sewer reaches comprising approximately 41.0% of the sanitary and combined sewers in the
9 MSD’s consent decree was amended on June 22, 2018. This amendment extended the construction schedule for certain
combined sewer overflow storage tunnels in the River Des Peres watershed by five years. MSD also agreed to invest $20 million
in green infrastructure in its Lemay Service Area/River Des Peres Watershed.
10 Metropolitan St. Louis Sewer District. 2013. Deer Creek watershed sewer system evaluation survey. Completed December 31,
2013. 2,116pp.
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watershed, were carried out in suspected problems areas (thus may not be indicative of the entire
watershed). Of the sewer reaches that were televised, approximately 50.2% had major to moderate
structural issues or root intrusion warranting strong or medium attention by MSD.
I/I studies were conducted in higher priority areas of the watershed identified by their potential for
causing or contributing to SSOs or building backups. I/I was attributed to both public and private defects.
Public defects are found on sewers and manholes located on public ground or easement and maintained
by MSD. Private defects are found on private property. Public defects included direct connections,
indirect connections, mainline defects, manhole cover defects, manhole frame defects, and manhole
structure defects. There were 11 direct connections (e.g. stormwater inlet connected to the sanitary
system) of inflow among the public defect findings. Private sources of I/I were the result of the following
defective components: downspouts; cleanouts; laterals; drains (i.e. yard drains, driveway drains, basement
entry drains, foundation drains, etc.); and, plumbing inside buildings. Overall, most defects in the study
were the result of defective manhole frames, manhole structures, private drains, cleanouts and private
laterals. Defect categories that may have the greatest impact on wet weather flows (average flow per
defect) associated with overall I/I included direct connections, indirect connections, downspouts,
mainlines, manhole covers and private drains.
The SSES resulted in a total of 38,156 defects with an associated flow estimated at 171,763 gallons per
minute (gpm ) from both public and private sources. In total, there were 14,970 (39%) private defects
with an associated flow estimated at 94,864 gpm (55%). From the public sewer system, there were 23,186
(61%) defects with an associated flow estimated at 76,899 gpm (45%). Furthermore, the number of
inflow defects totaled 30,483 (80%) providing an associated flow estimated at 155,474 gpm (91%).
Whereas, infiltration defects totaled 7,673 (20%) providing an associated flow estimated at 16,289 gpm
(8%). The SSES report for the Deer Creek watershed contains a complete summary of I/I estimated flows
and attributed sewer defects.
3.2.1.2 Master Plan Projects
As a result of an extensive planning process that included the SSES among other reports, 89 SSO Control
Master Plan projects were originally scheduled in Deer Creek watershed. Of these 89 projects, 28 were
located in the Black Creek watershed. Appendix A includes a table with all SSO Control Master Plan
projects for both Black Creek and Deer Creek watersheds. Projects listed in the table include schedules
for I/I reduction related to both public and private sources, sanitary relief and storage, and other system
improvements. Public and private work includes remedial measures to address their respective defects as
described in the previous section. All work is usually scheduled ahead of Master Plan dates to ensure
compliance with timelines in MSD’s consent decree.
Thirty-six (36) projects in the SSO Control Master Plan for Black Creek and Deer Creek watersheds
address cost effective I/I reduction within the sanitary system. Among these projects are those which also
included a plan/phase for Sewer Separation (2), Infrastructure Repair (1) and a Work Order to remove
constructed SSO Outfall BP-496. The purpose of I/I reduction projects is to reduce public and private
inflow and infiltration into the sanitary system to provide sanitary system capacity to convey flow and
reduce SSOs and building backups. Inflow occurs when stormwater enters the sanitary sewer through
direct connections. Sources of inflow can include connections from stormwater sewers, roof drains,
defective laterals and lateral cleanouts, and other drains for yards, driveways, basement entries,
foundations, etc. Infiltration occurs when groundwater enters the sanitary sewer system through cracks
and other openings in defective or deteriorated sewers, or when stormwater cross connections and/or
parallel connections with the sanitary sewer system exist. Cracks or openings may be caused by age
related deterioration, loose joints, installation errors, damage, or root infiltration. During storm events
inflow and infiltration sources influence sewer flows differently, with inflow impacting the sewer
immediately and infiltration impacting the sewer over an extended period of time following the event.
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Forty-three (43) projects focus on sanitary relief (in most cases they were preceded by I/I reduction
activities). Among these projects, one (1) also included a Storage plan/phase and one (1) included a
Work Order plan/phase to eliminate constructed SSO Outfall BP-196. The purpose of sanitary relief is to
increase the capacity of the sewer to handle wet weather peak flows without experiencing surcharging
sufficient to cause SSOs, including causing failure of the largest pump in any pumping station and/or
primary power failure to any pumping station. Perhaps most noteworthy of the sanitary relief projects is
the Deer Creek Sanitary Tunnel which is a permanent storage facility 3.9 miles in length, 19 feet in
diameter, and located 150-250 feet below ground to temporarily store wet weather volume. The Deer
Creek Sanitary Tunnel extends from Clayton Road to the River des Peres at Interstate 44 and is designed
to relieve the communities of Clayton, Richmond Heights, Brentwood, Maplewood, Webster Groves and
Shrewsbury of building backups and sewer overflows during heavy rain events. Construction work is
expected to be completed in late 2022 with a total cost of approximately $180 million.
In addition to the work summarized above, four (4) SSO Control Master Plan projects include separate
plan/phases for both I/I removal and sanitary relief. Among these projects, one (1) project also included a
Work Order plan/phase to remove constructed SSO outfalls BP-471, BP-607 and BP-627.
Four (4) SSO Control Master Plan projects included a Work Order plan/phase for the purpose of
eliminating constructed SSO outfalls. Finally, two (2) SSO Control Master Plan projects include a single
Elimination plan/phase to decommission and abandon two sanitary pump stations, those being Windmoor
Pump Station (P-710) and Horton Pump Station (P-814).
Collectively, the 89 SSO Control Master Plan projects include 112 unique plan/phases. Of these
plan/phases, 24 have not yet started, nine (9) are in the initial design phase, 7 have commenced
construction, 65 have been completed and seven (7) projects were determined to not be needed after other
system improvements were monitored. The 65 phases which have been completed addressed private and
public I/I reduction, sanitary relief, sewer separation and constructed SSO outfall removal (See Appendix
A).
As noted previously, there are 26 constructed SSO outfalls that remain active in Black Creek and Deer
Creek watersheds. Those constructed SSO outfalls will be eliminated through the completion of 12
unique SSO Control Master Plan projects. Those constructed SSO outfalls along with their respective
projects are as follows:
• BP-155, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-170, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-198, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-348, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-545, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-591, DC-02 & DC-03 Sanitary Relief (Brentwood Blvd to Conway Rd)
• BP-187, West Lockwood Sanitary Relief
• BP-013, Black Creek - Haddington Court Relief Sewers
• BP-017, Black Creek - Haddington Court Relief Sewers
• BP-018, Black Creek - Haddington Court Relief Sewers
• BP-151, Black Creek - Haddington Court Relief Sewers
• BP-583, Black Creek – Haddington Court Relief Sewers
• BP-156, WW-2 and WW-3 Warson Woods Sanitary Relief
• BP-501, WW-2 and WW-3 Warson Woods Sanitary Relief
• BP-194, Webster Groves Trunk E Sanitary Relief (SKME-628)
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• BP-578, Webster Groves Trunk E Sanitary Relief (SKME-628)
• BP-623, S Brentwood Blvd Sanitary Relief (Daytona Dr to Walinca Terrace)
• BP-003, BC-01 Phase III and BC-02 Phase II Sanitary Relief (I-170 to Heatherwood Dr)
• BP-004, BC-01 Phase III and BC-02 Phase II Sanitary Relief (I-170 to Heatherwood Dr)
• BP-014, BC-01 Phase III and BC-02 Phase II Sanitary Relief (I-170 to Heatherwood Dr)
• BP-016, BC-01 Phase III and BC-02 Phase II Sanitary Relief (I-170 to Heatherwood Dr)
• BP-015, Delcrest Sanitary Relief
• BP-094, Delcrest Sanitary Relief
• BP-158, Glenway Dr Sanitary Relief (Manchester Rd to Belson Ct)
• BP-605, Claytonia Creek Sanitary Relief (Hampton Creek Trunk Sewer to Clayton
Road)
• BP-634, Lower Black Creek and Hampton Creek Sanitary Relief (Deer Creek Trunk to
Oxford Dr) Phase II
The remaining Master Plan projects are scheduled for anticipated completion from 2021 through 2034.
These projects in large part focus on providing sanitary relief and will correct defects and eliminate
sources of I/I that deprive the system of capacity where necessary. By completing Master Plan projects
the frequency of SSO occurrences and the release of bacteria into the watershed will be reduced. The
status of projects listed in Appendix A will be submitted with each SWMP Annual Report. Completion
of Master Plan projects will aid in the reduction of bacteria to Black Creek and Deer Creek.
3.2.2 Capacity, Management, Operations, and Maintenance Program
MSD’s Capacity, Management, Operations, and Maintenance (CMOM) Program operates with goal of
maintaining established service levels and minimum performance standards. MSD’s CMOM Program
conducts the following activities:
1. Inspects 280 miles of sanitary sewer by CCTV each year, and annually reports location and
number of miles of sewer pipe inspected.
2. Acoustically inspects all sewers 15 inches or less in the separate system on a six year cycle. All
sewers that score an acoustic inspection rating of 0 to 5 will be cleaned. Clean all sewers greater
than 15 inches and less than or equal to 21 inches in the separate system on a six year cycle.
Clean all sewers less than or equal to 21 inches in the combined system on a five year cycle.
Clean all sewers greater than 21 inches as needed. MSD annually reports the number of miles
and locations of all sewer pipes that are acoustically inspected or cleaned.
3. Inspects 15,000 manholes annually and performs manhole frame adjustments as needed (there is
no yearly target for manhole frame adjustments), and performs repairs, rehabilitations, and/or
replacements on all manholes with a condition rating of 4 or 5 within one year of discovery.
MSD annually reports locations and number of manholes inspected, total number of manhole
frame adjustments performed, and manholes that were permanently
repaired/rehabilitated/replaced.
4. Permanently repairs, rehabilitates, and/or replaces at least 90 miles of sewer pipe each year (the
target of 90 miles will be reduced to 65 miles in 2022), and repairs all acute defects within one
year of discovery. MSD annually reports the locations and number of miles of sewer pipes that
were repaired/rehabilitated/replaced, as well as the locations and number of acute defects that
were repaired.
5. Inspects all 271 pump stations. Inspection frequency is no less than monthly for all collection
system pump stations with a hydraulic capacity below 1 million gallons per day (MGD), and no
less than weekly for pump stations greater than 1 MGD in peak hydraulic capacity. Overflow
Regulation Systems (ORS) and Relief pump stations are inspected no less than monthly
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regardless of capacity. MSD annually reports the number of inspections for each pump station as
well as its capacity range.
6. Visual inspections and non-destructive testing of force mains. Force mains categorized as critical
are inspected visually each year and by non-destructive testing once every five years. Force
mains categorized as non-critical are inspected visually once every five years. All defects
discovered during inspection and testing are repaired within one year. MSD annually reports
locations and numbers of force main assets in each risk category that have undergone visual
inspection, non-destructive testing, and have been repaired/replaced per risk.
CMOM activities will be carried out within Black Creek and Deer Creek watersheds and can be expected
to contribute to reduced bacteria loading. CMOM activities will be reported as required under the MSD’s
consent decree, and will not be reported as part of this ARAP. Implementation of BMP #4 in Section 3.3
TMDL Best Management Practices Targeting Bacteria however, may help detect the CMOM Program
Plan’s impact on bacteria loading to Black Creek and Deer Creek.
3.2.3 Fats, Oil, and Grease Program
The consent decree also includes requirements for MSD to control fats, oil, and grease (FOG) to ensure
their accumulations are not restricting the capacity of the sewer system and causing sanitary sewer
overflows. Under the FOG Control Program Plan, MSD identifies and inspects commercial
establishments/food service establishments (FSEs) and industrial facilities prone to FOG accumulations.
Facilities located in problem areas with reoccurring grease blockages that result in SSOs or in areas with
collection system defects are inspected on a periodic schedule with greater frequency (i.e. quarterly, semi-
annual, or annual). Routine periodic FSE inspections of FOG equipment are conducted every two to five
years when the sewer is in a moderate to low risk area. FSE inspection frequency may be greater than
five years in low risk areas with exceptionally large diameter sewer pipes. Other FSE inspections can
occur in response to FOG related complaints, or more randomly when investigators notice a new facility
while in the field, or if an existing facility has undergone a name change. Within MSD’s service area
there are approximately 4,900 facilities having the potential to discharge significant amounts of FOG into
the sanitary sewer system.
Within Black Creek and Deer Creek watersheds, there are 521 active FSEs and 37 that are listed as
having been decommissioned11. Over a three year period from 2018 through 2020, 3,432 FSE inspections
were performed, resulting in 14 enforcement actions. Over this same period, three (3) sanitary sewer
overflows were found to be caused by grease blockages.
FSE inspections and enforcement actions are reported annually under MSD’s consent decree, and thus
will not be reported in this ARAP. Instead, implementation of BMP #4 in Section 3.3 TMDL Best
Management Practices Targeting Bacteria, may help detect the FOG Program’s impact on bacteria
loading to Black Creek and Deer Creek.
3.3 TMDL Best Management Practices Targeting Bacteria
Beyond activities carried out under the SWMP and MSD’s consent decree, specific TMDL BMPs will be
implemented in order to further reduce the bacteria loading in Black Creek and Deer Creek. These BMPs
are specifically designed to improve the monitoring and management of potential sources of bacteria in
the watershed. TMDL BMPs are shown in Table 6, and are set to begin in 2034, which is the first year
following removal of the last constructed SSO outfall in Deer Creek watershed. Removal of the last
constructed SSO outfall (BP-634) in Deer Creek watershed will be accomplished by Lower Black Creek
and Hampton Creek Sanitary Relief (Deer Creek Trunk to Oxford Dr) Phase II. This project is located in
the Black Creek subwatershed and will provide relief to the sanitary sewer through significant capacity
11 FSE data regarding active and decommissioned establishments was obtained on 8/13/2021.
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improvements while also eliminating BP-634. Construction of Lower Black Creek and Hampton Creek
Sanitary Relief (Deer Creek Trunk to Oxford Dr) Phase II is currently scheduled to be completed in May,
2034; however, constructed SSO outfall BP-634 is anticipated to be removed in 2033 per the Consent
Decree.
As mentioned in Section 3.2.1.2 Master Plan Projects, the status of SSO Control Master Plan projects
listed in Appendix A will be reviewed annually and submitted with each SWMP Annual Report. Should
removal of the last constructed SSO outfall occur early, the schedule of TMDL BMP implementation
activities as outlined in Table 6 will be adjusted accordingly. Adjustments to the schedule would be
submitted to DNR with the SWMP annual report.
Prior to the start of TMDL BMP implementation, similar ARAP activities will have already been
conducted in Fishpot Creek watershed and others impaired by bacteria within MSD’s MS4 area. This
will lend valuable experience and other “lessons learned” which can be harnessed to ensure that effective
approaches are implemented in Black Creek and Deer Creek watersheds.
Among the seven TMDL BMPs listed in Table 6, BMPs will include visual inspections of the storm
sewer to identify potential sources of bacteria (TMDL BMP #2) and subsequent response efforts to
eliminate those sources that have been confirmed (TMDL BMP #3). Currently MSD utilizes crawl crews
and CCTV inspections to inspect and assess the condition of large and small storm sewer systems.
Findings from these inspections will include the location of direct connections into storm sewer mains,
inlets, and manholes. Where private connections are discovered, they will be reported to MSD’s Division
of Environmental Compliance to investigate for and identify sources of E. coli bacteria that feed into the
private storm sewer connections. Based on the findings of the investigations, appropriate action will be
taken to eliminate discovered sources of E. coli bacteria associated with the connection. For instance, this
could be an improperly connected house lateral, septic system, or a drainage area served by a drain that is
populated by pet owners or livestock. Work pertaining to TMDL BMPs #2 and #3 is scheduled through
2038. Data obtained from visual inspections of the storm sewer system, including but not limited to
CCTV and Crawl Crew inspections, conducted in other watersheds with bacterial TMDL ARAPs in the
MS4 area will be used to evaluate the effectiveness of visual storm sewer inspections overall and help
determine the best methods for this activity in Black Creek and Deer Creek watersheds. It is anticipated
that visual storm sewer inspections will be improved and refined over time, becoming more effective at
identifying and eliminating bacteria sources. While TMDL BMPs #2 and #3 are planned though 2038,
they may be completed ahead of schedule or remain ongoing.
In accordance with MS4 Permit Sections 6.1.J and 6.1.K, TMDL BMPs listed in Table 6 of this section
will be implemented according to the provided schedule only after this TMDL ARAP receives MDNR’s
approval. Therefore, MSD respectfully requests MDNR’s approval of this TMDL ARAP.
Implementation activities in the SWMP and MSD’s consent decree will be carried out according to their
previously determined and ongoing schedules. All TMDL BMPs shall be reviewed and evaluated for
effectiveness at least three times: 1) prior to the start of the TMDL BMP implementation schedule in
Table 6; 2) at the end of year five of each MS4 permit (the MS4 permit has not been developed for the
implementation period and this date is not yet known); and 3) following completion of all TMDL BMP
implementation activities.
During development of this Black Creek and Deer Creek E. coli TMDL ARAP, MSD and its co-
permittees are operating in the first year of the fourth term SWMP and MS4 permit. By the start of
TMDL BMP implementation, SWMP activities will have undergone multiple iterative reviews. In
addition, all 26 active constructed SSO outfalls will have been eliminated and the Deer Creek Sanitary
Tunnel will be in operation, reducing wet weather discharges into Deer Creek. MSD will continue to
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monitor water quality within Black Creek and Deer Creek as a result of these efforts, and factor that data
into decisions to adjust certain TMDL BMPs and their implementation schedules.
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Table 6. TMDL Best Management Practices Targeting Bacteria in Black Creek and Deer Creek Watersheds.
1BMP is based on outcome of the SWMP BMP #39 (fourth term).
2BMP is based on outcome of SWMP BMP #40 (fourth term).
3Denotes period for iterative review of BMP effectiveness. In 2034, there will be a review of TMDL BMPs prior to implementation. Iterative review will also take place at the end of Permit Year 5, which is currently not known for the implementation period.
# BMP Description BMP Purpose Expected
Result of BMP
Measurable Goals and Milestone Dates
Permit Year 1 - 5,
2021/2022 - 2026
2027-
2033 20343 2035 2036 2037 20383
BMP Evaluation
Process/Criteria
1
Determine extent of
rehabilitated sewers along
Black Creek, Deer Creek
and tributaries. Compare to
in-stream E.coli data.
Identify extent and
percent of rehabbed
sewers within defined
proximity to Black Creek,
Deer Creek and
tributaries. Identify
potential relationships
with instream E. coli and
need for sewer
rehabilitation work.
Map and summary
table of rehabbed
sewers within
defined proximity
to Black Creek,
Deer Creek and
tributaries.
None None Generate map and
summary table.
Generate map and
summary table.
Generate map and
summary table.
Generate map and
summary table.
Generate map and
summary table.
Map and summary table developed and
updated.
2
Identify potential sources of
bacteria through visual
inspections of the storm
sewer system.
Identify sources of
bacteria to Black Creek
and Deer Creek.
Summary of
bacteria findings.
None None Commence visual
inspections.
Report findings
from 2034.
Continue visual
inspections.
Report findings
from 2035.
Continue visual
inspections.
Report findings
from 2036.
Continue visual
inspections.
Report findings
from 2037.
Continue visual
inspections.
Summary table with bacteria findings
developed.
3
Respond to or eliminate
potential human related
sources of bacteria identified
through visual inspections of
the storm sewer systems.
Reduce bacteria loading to
Black Creek and Deer
Creek.
Summary of
response actions.
None None Respond to bacteria
findings and
eliminate illicit
discharges
identified during
visual inspections.
Report 2034
response actions.
Continue to respond
to bacteria findings
and eliminate illicit
discharges
identified during
visual inspections.
Report 2035
response actions.
Continue to respond
to bacteria findings
and eliminate illicit
discharges
identified during
visual inspections.
Report 2036
response actions.
Continue to respond
to bacteria findings
and eliminate illicit
discharges
identified during
visual inspections.
Report 2037
response actions.
Continue to respond
to bacteria findings
and eliminate illicit
discharges
identified during
visual inspections.
Summary table with response actions
developed.
4
Assess E. coli data collected
by MSD in previous year
and evaluate loading and
trends.
Track E. coli levels and
bacteria loading.
Summary table
with E. coli
measurements,
loading rates, and
trends.
None None Summarize 2033
E. coli loading and
trend.
Summarize 2034
E. coli loading and
trend.
Summarize 2035
E. coli loading and
trend.
Summarize 2036
E. coli loading and
trend.
Summarize 2037
E. coli loading and
trend.
Summary table with E. coli measurements,
loading rates, and trend developed and
updated.
51
Summarize survey data from
inspections of known
individual sewage disposal
systems in Black Creek and
Deer Creek watersheds.
Track properties that may
be a potential source of
bacteria to Black Creek
and Deer Creek due to
improper operation of an
individual sewage
disposal system.
Map and list of
inspected
properties with an
individual sewage
disposal system
that may be a
potential source of
bacteria to Black
Creek and Deer
Creek.
None None Develop results
based map and list
of properties with
individual sewage
disposal systems
inspected by DEC
in 2033.
Develop results
based map and list
of properties with
individual sewage
disposal systems
inspected by DEC
in 2034.
Develop results
based map and list
of properties with
individual sewage
disposal systems
inspected by DEC
in 2035.
Develop results
based map and list
of properties with
individual sewage
disposal systems
inspected by DEC
in 2036.
Develop results
based map and list
of properties with
individual sewage
disposal systems
inspected by DEC
in 2037.
Results based map and list of properties
with an individual sewage disposal system
inspected by DEC developed.
62
Update database of
properties that participated
in a sewer lateral repair
program in Black Creek and
Deer Creek watersheds.
Track improvements to
problematic infrastructure
and elimination of
potential sources of
bacteria.
Have a database of
properties that
participated in a
lateral repair
program.
None None Develop map and
list of properties.
Develop map and
list of properties.
Develop map and
list of properties.
Develop map and
list of properties.
Develop map and
list of properties.
Map and list of properties with repaired
sewer laterals developed.
7
Summarize maintenance of
individual sewage disposal
systems documented by
MSD’s Hauled Waste
Program for Black Creek
and Deer Creek watersheds.
Have a list of properties
that maintain their
individual sewage
disposal system.
Develop a list of
properties that
maintain their
individual sewage
disposal system.
None None Obtain 2033 records
from Hauled Waste
Program, add to list,
and report.
Obtain 2034 records
from Hauled Waste
Program, add to list,
and report.
Obtain 2035 records
from Hauled Waste
Program, add to list,
and report.
Obtain 2036 records
from Hauled Waste
Program, add to list,
and report.
Obtain 2037 records
from Hauled Waste
Program, add to list,
and report.
List of properties that maintain their
individual sewage disposal system
developed.
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4.0 Evaluation
Activities described in this TMDL ARAP will target bacteria sources in Black Creek and Deer Creek and
aim to reduce the overall bacteria load contributing to their impaired status. All activities will be carried
out through implementation of the SWMP, Project Clear and the federal consent decree, or as scheduled
in Section 3.3 of this document, TMDL Best Management Practices Targeting Bacteria.
TMDL BMPs listed in Section 3.3 of this document will be implemented according to the schedule found
in Table 6. With the first efforts completed by the Fishpot Creek bacteria TMDL ARAP and others
commencing prior to this watershed, opportunities for “lessons learned” exist. Outcomes of earlier efforts
accomplished in those watersheds will be considered for implementation into this ARAP, either as a
modification to a proposed activity or an additional activity. Such changes to this ARAP schedule could
occur either prior to, or after its commencement, and would be subject to MDNR approval.
TMDL BMPs #2 and #3 are scheduled through 2038, but depending on lessons learned in ARAPs that
were implemented earlier, both BMPs may be completed ahead of schedule or remain ongoing in order to
maximize the effectiveness of visual storm sewer inspections at identifying and eliminating sources of
pathogens. Each TMDL BMP shall be reviewed and evaluated for effectiveness as described earlier to
determine if they should be replaced or modified in order to achieve further progress towards reducing the
bacteria load to Black Creek and Deer Creek. TMDL BMP effectiveness will be largely based on water
quality data as evaluated under TMDL BMP #4.
In line with MS4 Permit Section 6.1.C, implementation of the Black Creek and Deer Creek E. coli TMDL
ARAP will be completed as soon as practicable, but is anticipated to span years or even multiple permit
terms.
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Appendix A
SSO Control Master Plan Projects in Black Creek and Deer Creek Watersheds
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Project Name* Watershed Plan/Phase Project Description** Commence - Complete
Construction
Ballas Road Subtrunk South I/I Reduction Deer Creek Public I/I Rehabilitate 60,300 Feet of Public Sewers using the Cured-In-Place Pipe Method. 1/26/2015 - 1/3/2017
Private I/I Remove Private I/I Sources from Sanitary Sewers. 8/18/2015 - 3/20/2017
BC-01 Phase III and BC-02 Phase II Sanitary Relief
(I-170 to Heatherwood Dr) Black Creek Sanitary Relief Construct 13,000 Feet of 8-inch to 36-inch Sanitary Sewer. Eliminate
Constructed SSO Outfalls BP-003, BP-004, BP-014, and BP-016. 11/22/2027 - 8/13/2031
Black Creek - Haddington Court Relief Sewers Black Creek Sanitary Relief Construct 7,955 Feet of 8-inch to 42-inch Sanitary Sewer, and Eliminate
Constructed SSO Outfalls BP-013, BP-017, and BP-151. 5/19/2023 - 2/7/2027
Sanitary Relief Construct 530 Feet of 21-24 inch Sanitary Sewer and Eliminate Constructed SSO Outfall BP-018. 6/1/2023 - 6/10/2024
Black Creek I/I Reduction Black Creek
Public I/I Remove Excessive I/I from Public and Private Sources by Rehabilitating 62,000 Feet of Pipe Sewers
and Manholes and by Removing Private Defects. 8/26/2014 - 10/31/2017
Public and Private I/I Construct 2,200 Feet of 12-inch Storm Sewer and Remove Private I/I Sources at 22 Properties. 11/18/2015 - 1/31/2017
Private I/I 5/18/2017 - 6/14/2018
Bompart Ave Sanitary Relief
(Deer Creek Trunk to Manchester Rd) Deer Creek Sanitary Relief
Construct 10,500 Feet of 8-inch to 36-inch Sanitary Sewer, and 3,600 Feet of 12-inch to 36-inch Storm Sewer.
Perform Public and Private I/I Reduction to Facilitate Combined Sewer Separation. Remove Interceptor I-132
and CSO Outfall L-106.
6/3/2023 - 6/12/2025
Bopp Sanitary Relief (SKME-611) Deer Creek Work Order Constructed SSO Outfall BP-495 Removal Only. Eliminated by WO #4240083 on 9/22/17. -
Brentwood Forest, Fair Oaks, Middlesex I/I Reduction
(I-64 and Lay Rd) Black Creek Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-in-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 665 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 46 Properties. 3/17/2020 - 5/3/2021
Briarcliff St to Briar Oak St Sanitary Relief Black Creek Sanitary Relief Construct 1,300 Feet of 12-inch Sanitary Sewer. 8/13/2032 - 8/18/2033
Cedarcrest Sanitary Relief (SKME-561) I/I Reduction Black Creek
Public I/I Remove Excessive I/I from Public Sources by Rehabilitating 55,000 Feet of Pipe Sewers and Manholes. 3/13/2014 - 8/31/2015
Private I/I Construct 1,300 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources at 11 Properties. 6/13/2014 - 3/2/2015
Private I/I 3/13/2015 - 9/8/2015
Cella Sanitary Relief (Rolling Rock Ln to Clayton Rd) Deer Creek Sanitary Relief Construct 6,600 Feet of 12-inch to 18 -inch Sanitary Sewer. 3/1/2027 - 9/1/2028
Cella - Rolling Rock - Glen Creek Sanitary Sewer
and Public I/I Reduction Deer Creek Private I/I Construct 665 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 46 Properties. 3/17/2020 - 5/3/2021
Clark Ave Sanitary Relief (Laclede Sta Rd to Yeatman Ave) Deer Creek Sanitary Relief Construct 1,270 Feet of 18-inch Sanitary Sewer. 5/1/2024 - 1/31/2026
Claverach Park I/I Reduction and Sewer Separation Black Creek
Public I/I Rehabilitation of the Sanitary Sewer System to Reduce Public I/I. 2/18/2014 - 7/17/2016
Private I/I Remove Excessive I/I from Public and Private Sources by Rehabilitating 6,000 Feet of Pipe Sewers and
Manholes and by Removing Private Defects. Also Separate 500 Feet of Combined Sewer
12/18/2015 - 2/10/2017
Sewer Separation
and Private I/I 2/3/2017 - 10/3/2017
Clayton Road Sanitary Relief (Westwood Dr to Cromwell Dr) Black Creek Sanitary Relief Construct 1,700 Feet of 24-inch Sanitary Sewer. Disconnect Diversion to Combined Sewer at 19J4-043S. 3/1/2032 - 12/1/2033
Claytonia Creek Sanitary Relief
(Hampton Creek Trunk Sewer to Clayton Road) Black Creek Sanitary Relief Construct 6,900 of 18-inch to 48-inch Sanitary Sewer, and Eliminate Constructed SSO Outfall BP-605. 8/13/2030 - 11/5/2033
Concordia I/I Reduction
(NE Quad Clayton Rd and Big Bend Blvd) Black Creek Public I/I Rehabilitate 29,600 Feet of Public Sewers using the Cured-in-Place Pipe Method. 1/25/2016 - 7/20/2018
Private I/I Remove Private I/I Sources from Sanitary Sewers. 11/28/2016 - 11/30/2017
Conway Road Sanitary Relief (Conway Ln to Dwyer Ave) Deer Creek Sanitary Relief Construct 880 Feet of 8-inch to 15-inch Sanitary Sewer. 4/19/2024 - 4/23/2025
Conwood Ln Sanitary Relief (Conway Rd to Westwood Ct) Deer Creek Sanitary Relief Construct 4,600 Feet of 12-inch to 18 -inch Sanitary Sewer. 3/2/2024 - 3/1/2026
Crossroads, Hanley Industrial, Litzsinger East I/I Reduction
(SW I-64 and S Hanley Rd) Black Creek Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-in-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 665 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 46 Properties. 3/17/2020 - 5/3/2021
MSD & MS4 Co-permittees Black Creek and Deer Creek E. coli TMDL ARAP
30
Project Name Watershed Plan/Phase Project Description Commence - Complete
Construction
DC-02 & DC-03 Sanitary Relief
(Brentwood Blvd to Conway Rd) Deer Creek
Sanitary Relief Construct 7,900 Feet of 6-inch to 78-inch Sanitary Sewer to Alleviate System Surcharging. Facilitate Future
Removal of Constructed SSO Outfalls BP-545, BP-170, BP-198, BP-348, BP-349, BP-155, and BP-591. 2/16/2016 - 8/4/2018
Sanitary Relief Construct 7,900 Feet of 66-inch to 72-inch Sanitary Sewer, to Alleviate System Surcharging and Facilitate the
Future Removal of Constructed SSO Outfalls. 3/28/2018 - 6/30/2021
Sanitary Relief Construct 16,200 Feet of 8-inch to 54-inch Sanitary Sewer, to Alleviate System Surcharging. Eliminate
Constructed SSO Outfalls BP-155, BP-170, BP-348, BP-349, BP-198, BP-545, and BP-591. 7/12/2019 - 10/8/2023
DC-04 Deer Creek Sanitary Relief Phase III
(Lakeshore Dr to New Ballas Rd) Deer Creek Sanitary Relief Construct 2,400 Feet of 12-inch to 18 -inch Sanitary Sewer. --
DC-06 Deer Creek Sanitary Relief Phase III and I/I Reduction Deer Creek
Public I/I Rehabilitate 85,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 11/5/2014 - 12/30/2016
Sanitary Relief
and Private I/I Construct 240 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources from Sanitary Sewers. 3/13/2015 - 5/26/2016
Work Order Constructed SSO Outfall BP-471 Removed by Operations on 5/21/18. Constructed SSO Outfalls BP-607 and
BP-627 Previously Removed by Project 10576. --
DC-09 West I/I Reduction
(S Lindbergh Blvd and Ladue Rd) Deer Creek Public I/I Rehabilitate 69,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 5/15/2017 - 11/13/2019
Private I/I Construct 505 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources from Sanitary Sewers. 9/18/2017 - 5/17/2018
Deer Creek Sanitary Tunnel (Clayton Rd to RDP) Deer Creek Sanitary Relief Construct 22,800 Feet of 19 Foot Diameter Storage Tunnel and Diversion Structures. 8/25/2017 - 12/8/2021
Sanitary Relief Construct A 21 MGD Pump Station Facility, For the Deer Creek Tunnel Project. 8/18/2020 - 8/27/2022
Delcrest Sanitary Relief Black Creek Sanitary Relief Construct 1,793 Feet of 12-inch to 18-inch Sanitary Sewers, and Eliminate
Constructed SSO Outfalls BP-015 and BP-094. 3/1/2028 - 9/2/2029
Delcrest Sanitary Relief (SKME-565) I/I Reduction Black Creek Public I/I Rehabilitation of the Sanitary Sewer System to Reduce Public I/I. 2/18/2014 - 7/17/2016
Private I/I Construct 1,500 Feet of 12-inch Storm Sewers, and Remove Private I/I Sources at 10 Properties. 11/14/2014 - 10/21/2015
Elinor Ave. Temporary Sanitary Storage Facility Black Creek Storage Construct 110 Feet of 8-inch to 24-inch Sanitary Sewer in order to Provide 1,400 Gallons of
Temporary Storage. Contingency Project to Eliminate Constructed SSO Outfall BP-008. 1/14/2019 - 6/10/2019
Fawn Valley, Pioneer Park, Westchester I/I Reduction
(Manchester Rd W of N Geyer Rd) Deer Creek Public I/I Rehabilitate 69,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 5/15/2017 - 11/13/2019
Private I/I Remove Private I/I Sources from Sanitary Sewers. 9/18/2017 - 2/1/2018
Frontenac, Winding Ridge, Deer Creek Hill I/I Reduction
(S Quad I-64 and Clayton Rd) Deer Creek Public I/I Rehabilitate 78,000 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 2/23/2018 - 3/16/2021
Private I/I Perform Private I/I Reduction at 20 Properties. 11/13/2018 - 6/18/2019
Glendale Section D Sanitary Relief Phase III
(SKME-624) I/I Reduction Deer Creek Private I/I Construction of Phase III of Sewer Improvements, to Include Rehabilitation of
Approximately 20 Private Laterals, Disconnection of Approximately 510 Roof Drains,
and Disconnection of Approximately 120 Area Drains.
6/14/2013 - 9/11/2014
Private I/I 6/13/2014 - 1/29/2016
Glendale Section D Sanitary Relief Phase IV
(SKME-624) I/I Reduction Deer Creek Public I/I Remove Excessive I/I from Public Sources by Rehabilitating 80,000 Feet of Pipe Sewers and Manholes. 8/9/2013 - 12/12/2015
Glendale Section D Sanitary Relief Phase V
(SKME-624) I/I Reduction Deer Creek Private I/I Construct 1,675 Feet of 12-inch to 18 -inch Storm Sewer and Remove Private I/I Sources from Sanitary Sewers. 11/13/2017 - 6/29/2018
Work Order Constructed SSO Outfall BP-496 Eliminated on 10/13/17 --
Glenway Dr Sanitary Relief (Manchester Rd to Belson Ct) Deer Creek Sanitary Relief Construct 5,200 Feet of 8-inch to 15-inch Sanitary Sewer, and Eliminate Constructed SSO Outfall BP-158. 2/18/2029 - 2/18/2031
Hawthorne Estates Sanitary Relief
(Ranch Ln to Clayton Hills Ln) Deer Creek Sanitary Relief Construct 1,870 Feet of 12-inch Sanitary Sewer. 4/20/2024 - 10/22/2025
Hermitage Sanitary Relief (SKME-615) Deer Creek Sanitary Relief Construct 3,700 Feet of 8-inch to 18-inch Sanitary Sewer, and Perform Private I/I Reduction at 1 Property.
Eliminate Constructed SSO Outfalls BP-181, BP-333, BP-343, and BP-555. 3/15/2019 - 6/9/2020
MSD & MS4 Co-permittees Black Creek and Deer Creek E. coli TMDL ARAP
31
Project Name Watershed Plan/Phase Project Description Commence - Complete
Construction
Horton Pump Station (P-814) Elimination Deer Creek Elimination Construct 1,535 Feet of 8-inch Sanitary Sewer. Decommission and Abandon Existing Pump
Station P-814 and Associated Forcemain. 1/27/2030 - 2/1/2031
Huntleigh Manor, Old Warson, Timberwyck I/I Reduction
(S Lindbergh Blvd South of Litzsinger Rd) Deer Creek Public I/I Rehabilitate 61,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 5/22/2017 - 6/17/2019
Private I/I Remove Private I/I Sources from Sanitary Sewers. 9/18/2017 - 6/30/2018
Huntleigh Trails Ln Sanitary Relief
(Two Mile Creek Trunk Sewer to N Geyer Rd) Deer Creek Sanitary Relief Construct 3,500 Feet of 15-inch to 24 -inch Sanitary Sewer. --
Kirkwood Middle School, Simmons, Wilson, W Sarah I/I Reduction
(Manchester Rd and Kirkwood Rd) Deer Creek Public I/I Rehabilitate 61,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 5/22/2017 - 6/17/2019
Private I/I Remove Private I/I Sources from Sanitary Sewers. 11/13/2017 - 9/24/2018
Ladue Estates Sanitary Relief Deer Creek
Public I/I Rehabilitate 29,600 Feet of Public Sewers using the Cured-In-Place Pipe Method. 1/25/2016 - 7/20/2018
Sanitary Relief
and Private I/I Construct 240 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources from Sanitary Sewers. 3/13/2015 - 5/26/2016
Ladue Estates Sanitary Relief
(Deer Creek Trunk Sewer to S Ladue Estates Dr) Deer Creek Work Order Constructed SSO Outfall BP-183 Eliminated by WO 5312692 on 10/29/19 --
Ladue Subtrunk Sanitary Relief (SKME-654) Deer Creek Private I/I Construct 80 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources from Sanitary Sewers. 2/10/2017 - 9/29/2017
Lay Rd - Galleria I/I Reduction
(Clayton Rd and Lay Rd) Black Creek Public I/I Rehabilitate 78,000 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 2/23/2018 - 3/16/2021
Private I/I Perform Private I/I Reduction at 49 Properties. 12/18/2018 - 7/19/2019
Lemay Watershed I/I Removal - North Hampton Creek Black Creek
Public I/I Rehabilitate 38,600 Feet of Public Sewers using the Cured-In-Place Pipe Method. 8/12/2016 - 2/11/2019
Private I/I Construct 18,180 Feet of 12-inch to 18-inch Storm Sewer, and Remove
Private I/I Sources from Sanitary Sewers. 2/10/2017 - 2/16/2018
Lower Black Creek and Hampton Creek Sanitary Relief
(Deer Creek Trunk to Oxford Dr) Black Creek Sanitary Relief Construct 7,500 Feet of 12-inch to 72 -inch Sanitary Sewer. 7/6/2023 - 9/28/2026
Lower Black Creek and Hampton Creek Sanitary Relief
(Deer Creek Trunk to Oxford Dr) PHASE II Black Creek Sanitary Relief
Construct 7,960 Feet of 30-inch to 54-inch Sanitary Sewer, and 710 Feet of 36-inch Pipe-In-Tunnel
Under I-64. Construct 2,600 Feet of Vertical Wall Channel, and
Construct 235 Feet of 48-inch by 66-inch Box Culvert. Eliminate BP-634.
3/1/2031 - 5/24/2034
Mark Twain I/I Reduction
(Manchester Rd and Bompart Ave) Deer Creek Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 665 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 46 Properties. 3/17/2020 - 5/3/2021
McCutcheon Rd and Thorndell Sanitary Relief Black Creek Sanitary Relief Construct 1,275 Feet of 12-inch to 15-inch Sanitary Sewer. 4/4/2024 - 10/6/2025
McKnight Place to Delmar Blvd Sanitary Relief Black Creek Sanitary Relief Construct 2,000 Feet of 15-inch Sanitary Sewer. 2/3/2031 - 8/6/2032
Meadowridge and Eastwood Storm and Sanitary Relief Deer Creek Sanitary Relief Construct Approx. 645-LF of 6-Foot by 3-Foot and 6-Foot by 4-Foot Reinforced Concrete Box
Culvert and Appurtenances and Construct 740-Lf of 15-In Sanitary Sewer Pipe and Appurtenances. 11/12/2015 - 6/10/2016
North Central Ave #14 Sanitary Sewer
(Infrastructure Repair) Black Creek Infrastructure
Repair Replace Manhole and 77 Feet of Sanitary Sewer. 6/18/2014 - 8/12/2014
North Forest and Brookside I/I Reduction
(Summit Ave and Marshall Ave) Deer Creek Public I/I Rehabilitate 78,000 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 2/23/2018 - 3/16/2021
Private I/I Perform Private I/I Reduction at 67 Properties. 11/13/2018 - 5/30/2019
North Webster CC, Pocahontas, South Brentwood I/I Reduction
(S Brentwood Blvd and Manchester) Deer Creek Public I/I Rehabilitate 78,000 Feet of the Public Sewer System using the Cured-in-Place Pipe Method. 2/23/2018 - 3/16/2021
Private I/I Perform Private I/I Reduction at 84 Properties. 1/14/2019 - 7/29/2019
Paxton Sanitary Relief
(SKME-562) (Ladue Rd to Dielman Rd) Black Creek Sanitary Relief Construct 9,900 Feet of 12-inch to 24 -inch Sanitary Sewer. 11/10/2030 - 5/8/2033
Powell Ave and Annalee Sewer Separation Deer Creek Sewer
Separation Replace 700 Feet of 8-inch Diameter Sanitary Sewer and Redirect Sanitary Flow from Combined Sewer. 7/13/2015 - 12/18/2016
MSD & MS4 Co-permittees Black Creek and Deer Creek E. coli TMDL ARAP
32
Project Name Watershed Plan/Phase Project Description Commence - Complete
Construction
Providence Sanitary Relief (SKME-640) Deer Creek
Public I/I Rehabilitate 22,500 Feet of Public Sewers using the Cured-In-Place Pipe Method. 1/21/2015 - 12/20/2016
Private I/I Construct 780 Feet of 8-inch Sanitary Sewer, 215 Feet of 12-inch Storm Sewer, and
Remove Private I/I Sources from Sanitary Sewers. 1/19/2016 - 10/4/2017
Ridgemoor Drive I/I Reduction & Storm Improvements (SKME-574) Black Creek Private I/I Construct 1,000 Feet of 12-inch to 24 -inch Storm Sewer, Construct Underground
Detention System, and Remove Private I/I. 3/11/2016 - 3/20/2017
Rock Hill Sanitary Relief (SKME-618) Deer Creek Public I/I Remove Excessive I/I from Public Sources by Rehabilitating 47,500 Feet of Sewers and Manholes. 2/18/2014 - 7/16/2016
Private I/I Construct 70 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources at 2 Properties. 10/15/2015 - 3/9/2017
Rosedale Ave Sanitary Relief
(Newport Ave to Arbor Ln) Deer Creek Sanitary Relief Construct 310 Feet of 12-inch Sanitary Sewer. --
Roxbury I/I Reduction Black Creek Public I/I Rehabilitation of the Sanitary Sewer System to Reduce Public I/I. 2/18/2014 - 7/17/2016
Private I/I Construct 1,600 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources at 15 Properties. 1/9/2015 - 11/25/2015
Russell Ave Sanitary Relief
(Deer Creek Trunk to Manchester Rd) Deer Creek Sanitary Relief Construct 2,900 Feet of 15-inch to 18 -inch Sanitary Sewer. --
S Brentwood Blvd Sanitary Relief
(Daytona Dr to Walinca Terrace) Black Creek Sanitary Relief Construct 2,800 Feet of 8-inch to 24-inch Sanitary Sewer, and
Eliminate Constructed SSO Outfall BP-623. 5/23/2023 - 11/23/2024
S Gore Ave Sanitary Relief
(Gray Ave to Oak Terr) Deer Creek Sanitary Relief Construct 1,700 Feet of 12-inch to 15 -inch Sanitary Sewer. --
S Lindbergh Blvd Sanitary Relief
(Clermont Ln to Ladue Rd) Deer Creek Sanitary Relief Construct 1,700 Feet of 12-inch Sanitary Sewer. 1/31/2029 - 8/4/2030
S McKnight Rd and Ladue Manor Ln Sanitary Relief Black Creek Sanitary Relief Construction 3,500 Feet of 15-inch to 24-inch Sanitary Sewer. 2/2/2031 - 11/3/2032
Sherwyn Sanitary Relief (SKME-651) and I/I Reduction Deer Creek
Public I/I Rehabilitate 85,000 Feet of Public Sewers using the Cured-In-Place Pipe Method. 11/5/2014 - 12/30/2016
Private I/I
and Sanitary Relief
Construct 1,675 Feet of 6-inch to 16-inch Sanitary Sewers and Remove Private I/I
Sources from Sanitary Sewers. Eliminate Constructed SSO Outfalls BP-199 &
Potentially BP-203 After Post-Construction Monitoring.
3/11/2016 - 7/17/2017
Spring Ave Sanitary Relief (Yeatman Ave to Dale Ave) Deer Creek Sanitary Relief Construct 2,460 Feet of 15-inch to 48-inch Sanitary Sewer, and Eliminate
Constructed SSO Outfall BP-440. 4/9/2021 - 6/7/2022
Stonington Place Sanitary Relief
(Clayton Rd to Georgian Acres St) Deer Creek
Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 238 Feet of 12-inch Sanitary Sewer. 12/20/2022 - 3/19/2025
Private I/I Construct 1,135 Feet of 15-inch to 33-inch Storm Sewer, 295 Feet of 8-inch
and 12-inch Dip Sanitary Sewer, and 12 Rain Gardens. 5/10/2018 - 2/6/2019
Stonington Sanitary Relief (SKME-652) Deer Creek
Public I/I Sewer Lining and Rehabilitation to Reduce Public I/I. 5/14/2013 - 4/13/2015
Sanitary Relief Construction of 3,310 Feet of 8-inch to 15-inch Sanitary Sewer, and
One Constructed SSO Outfall (BP-166) Is to Be Eliminated.
6/14/2013 - 10/22/2014
Private I/I 4/21/2011 - 3/28/2012
Strassner Ave Sanitary Relief
(Black Creek Trunk to Swallow Dr) Black Creek Sanitary Relief Construct 4,000 Feet of 21-inch to 30 -inch Sanitary Sewer. 3/1/2026 - 8/27/2028
Tilles Park, Litzsinger and Parkridge I/I Reduction
(Litzsinger Rd and S McKnight Rd) Deer Creek Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 1,200 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 37 Properties. 1/14/2020 - 10/7/2020
TM-01 Two Mile Creek Outfall Sanitary Relief Deer Creek Sanitary Relief Construct 11,400 Feet of 8-inch to 48 -inch Sanitary Sewer. 8/11/2023 - 8/5/2026
TM-03 Two Mile Creek Sanitary Relief
(Two Mile Trunk to Firethorn Dr) Deer Creek Work Order Constructed SSO Outfall BP-556 Eliminated by WO on 12/13/19. --
MSD & MS4 Co-permittees Black Creek and Deer Creek E. coli TMDL ARAP
33
Project Name Watershed Plan/Phase Project Description Commence - Complete
Construction
TM-04 Two Mile Sanitary Relief Phase II
(Lockett Rd to Meier Rd) Deer Creek Sanitary Relief Construct 580 Feet of 15-inch Sanitary Sewer. --
Upper Ladue Creek I/I Reduction
(NE Quad of S Warson Rd and Ladue Rd) Deer Creek Public I/I Rehabilitate 73,510 Feet of the Public Sewer System using the Cured-In-Place Pipe Method. 12/18/2018 - 9/19/2021
Private I/I Construct 665 Feet of 12-inch Storm Sewer, and Perform Private I/I Reduction at 46 Properties. 3/17/2020 - 5/3/2021
Villa Coublay Sanitary Relief Deer Creek Work Order Constructed SSO Outfall BP-203 Eliminated by WO 5312916 on 11/5/19. --
Warson Terrace Sanitary Relief
(Foxboro Rd to Conway Rd) Deer Creek Sanitary Relief Construct 1,000 Feet of 15-inch Sanitary Sewer. 2/18/2027 - 8/21/2028
Webster Groves Trunk E Sanitary Rehabilitation
and I/I Reduction Phase II Deer Creek Public I/I Rehabilitation of 79,700 Feet of 8-36 inch Sewer, 570 Manholes, and Repair 1,100 Service Connections. 7/12/2013 - 11/30/2015
Webster Groves Trunk E Sanitary Rehabilitation
and I/I Reduction Phase III Deer Creek Public I/I Construct 1,000 Feet of 8-inch to 15 -inch Sanitary Sewer. 9/17/2018 - 6/12/2019
Webster Groves Trunk E Sanitary Rehabilitation
and I/I Reduction Phase IV Deer Creek
Private I/I
Construct 3,200 Feet of 12-inch to 21 -inch Storm Sewer, and Perform Private I/I Reduction at 40 Properties.
10/12/2015 - 3/30/2017
Private I/I 10/15/2015 - 4/22/2017
Private I/I 4/15/2021 - 6/24/2021
Webster Groves Trunk E Sanitary Relief (SKME-628) Deer Creek Sanitary Relief Construct 10,500 Feet of 12-inch to 54 -inch Diameter Sanitary Sewer from
Sappington Road, North of East Essex to Marshall Road. 2/3/2025 - 1/29/2028
Webster Groves Trunk E Sanitary Relief (SKME-628) Phase 3 Deer Creek Sanitary Relief Construct 10,500 Feet of 12-inch to 54-inch Diameter Sanitary Sewer from
Sappington Road, North of East Essex to Marshall Road. 2/3/2025 - 1/29/2028
West Lockwood Sanitary Relief Deer Creek Sanitary Relief Construct 3,324 Feet of 8-inch to 30-inch Sanitary Sewer, and Eliminate
Constructed SSO Outfalls BP-187 and BP-587. 10/9/2020 - 11/30/2021
West Wise I/I Reduction (NW Quad I-64 and Big Bend Blvd) Black Creek Public I/I Rehabilitate 29,600 Feet of Public Sewers using the Cured-in-Place Pipe Method. 1/25/2016 - 7/20/2018
Private I/I Construct 5,000 Feet of 12-inch Storm Sewer, and Remove Private I/I Sources from Sanitary Sewers. 2/10/2017 - 3/15/2019
Wilson Ave Sanitary Relief (Harrison Ave to Cleveland Ave) Deer Creek Sanitary Relief Construct 700 Feet of 12-inch Sanitary Sewer. --
Windmoor Pump Station (P-710) Elimination Deer Creek Elimination Construct 1,300 Feet of 10-inch Sanitary Sewer. Decommission and Abandon Existing
Pump Station P-710 and Associated Forcemain. 1/27/2030 - 2/1/2031
Woodlawn Sanitary Relief Deer Creek Sanitary Relief Construct 3,000 Feet of 12-inch Sanitary Sewer. Contingency Project to Eliminate
Constructed SSO Outfall BP-196. 3/1/2029 - 8/28/2031
Work Order Constructed SSO Outfall BP-196 Early Elimination, WO # 4240085, Removed on 9-28-17. --
WW-2 and WW-3 Warson Woods Sanitary Relief Deer Creek Sanitary Relief Construct 10,900 Feet of 8-inch to 24-inch Sanitary Sewer. Eliminate
Constructed SSO Outfalls BP-156, BP-158, and BP-501. 3/26/2023 - 3/20/2026
Wydown Blvd and Westwood Dr Sanitary Relief Deer Creek Sanitary Relief Construct 860 Feet of 15-inch Sanitary Sewer. 2/19/2032 - 11/20/2033
* Status updates will be provided for each Master Plan project listed in Appendix A and submitted annually with the SWMP Annual report.
** Project description may change during the various project stages and may only describe latest phase.
MSD & MS4 Co-permittees Black Creek and Deer Creek E. coli TMDL ARAP
34
Appendix B
Bacteria and Nutrient Best Management Practices Strategy Review
2009 East McCarty Street, Suite 1
Jefferson City, Missouri 65101
PH 573.443.4100
FAX 573.443.4140
www.geosyntec.com
Memorandum
Date: December 23, 2016
To: Jay Hoskins, Metropolitan St. Louis Sewer District
From: Avery Blackwell, P.E., Brandon Steets, P.E., Scott Struck, P.E., Dan
Pankani, P.E. Geosyntec Consultants
Eric Dove, David Carani, HDR
Subject: Bacteria and Nutrient Best Management Practice Strategy Review
Geosyntec Project: MOW5165E Phase 90
Attachments: Attachment A - BMP Evaluation Results
Recent actions by the Missouri Department of Natural Resources (MDNR) will impact how the
Metropolitan St. Louis Sewer District (MSD) administers their stormwater management
program. These actions include publication of the Missouri Nutrient Loss Reduction Strategy 1,
completion of Escherichia coli (E. coli or bacteria) total maximum daily loads (TMDLs) for four
streams in the St. Louis area 2, and renewal of the statewide small municipal separate storm sewer
system (MS4) general permit (MOR-040000). Central to each of these actions is the requirement
for MS4 programs to implement best management practices (BMPs) via an iterative process to
reduce the discharge of pollutants into the MS4 to the maximum extent practicable (MEP).
The purpose of this memo is to briefly outline these recent MDNR actions and potential MS4
program impacts, generally characterize MSD’s existing structural and non-structural BMPs for
bacteria and nutrients relative to the state of the practice and other MS4 programs, and
recommend actions that MSD could pursue to further identify areas to enhance BMP
implementation. The results of this review are intended to help MSD characterize MEP for
controlling bacteria and nutrients in stormwater runoff.
1 http://dnr.mo.gov/env/wpp/mnrsc/docs/nlrs-strategy-2014.pdf 2 TMDLs for Coldwater Creek, Creve Coeur Creek, Fishpot Creek, and Watkins Creek were approved by EPA on
July 13, 2016.
Bacteria and Nutrient BMP Strategy Review
December 23, 2016
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MOW5165E | St. Louis | 2016(1223)_MSD_BMP_Evaluation_Memo
REGULATORY CONTEXT
As mentioned above, the Missouri Nutrient Loss Reduction Strategy (Nutrient Strategy), recently
approved bacteria TMDLs, and the newly-issued small MS4 general permit each require MSD to
evaluate current approaches for defining MEP. Evaluating approaches for defining MEP for
controlling bacteria and nutrient levels in a comprehensive fashion will assist MSD in
determining how best to define MEP. A brief description of these MDNR initiatives and their
impact on MSD’s stormwater management program are outlined below.
In December 2014, MDNR finalized the Nutrient Strategy which outlines a set of recommended
actions that MS4s and other nutrient sources could implement to reduce nutrient loads to the
Gulf of Mexico. Available data (provided by MSD) suggest that MS4s are a relatively minor
source of nutrients to the Gulf and that additional data are needed to characterize urban
stormwater loads. The Nutrient Strategy also acknowledges the role of state-mandated funding
limitations for stormwater programs, and the need for an interactive, efficient, and cost-effective
approach to address MS4 nutrients. To that end, the Nutrient Strategy identifies several actions
that MS4 agencies should complete over a five-year period (2015-2019) to better characterize
their programs and define MEP in the context of nutrient reductions. These include the
following:
• From 2015 to 2017, review public involvement and education programs and material and
make recommendations for enhancements to implement in 2018-2019 consistent with
available funding.
• From 2015 to 2019, review programs and identify appropriate structural and non-
structural BMP enhancements to implement in 2020 and beyond consistent with available
funding. At a minimum, MS4 agencies should consider how low-impact development
practices might improve nutrient management effectiveness.
In January 2015, MDNR finalized E. coli TMDLs for four streams in the St. Louis area; EPA
subsequently approved the TMDLs in July of 2016. These TMDLs identified MSD and several
of the MS4 co-permittees as point source contributors of bacteria in the watersheds. As MDNR
stated in the “Reasonable Assurance” section of each TMDL, “The wasteload allocations for
MS4s will be implemented through the NPDES MS4 permits with the ultimate goal to employ an
iterative process using BMPs to the MEP, assessment, and refocused BMPs to the MEP, leading
toward attainment of water quality standards (64 FR 68753)”. In the implementation plan, which
accompanied each TMDL, MDNR discussed MS4 stormwater management plan requirements to
address the six minimum control measures (MCM), and reiterated that BMPs and programs
developed under the MCMs are expected to result in bacteria reductions from the MS4 area.
Bacteria and Nutrient BMP Strategy Review
December 23, 2016
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MOW5165E | St. Louis | 2016(1223)_MSD_BMP_Evaluation_Memo
Since 2013, MDNR has also been working closely with stakeholders, including MSD, to revise
and reissue the statewide Phase II MS4 general permit. The permit was issued by MDNR on
October 1, 2016. The permit includes clarifying language that MS4 discharge limits are defined
as BMPs to the MEP. More specifically, Section 1.4.1 of the permit states, “The permittee shall
implement Best Management Practices (BMPs) via an iterative process to reduce the discharge
of pollutants to the Maximum Extent Practicable (MEP) into the MS4 for the goal of attainment
with Missouri’s Water Quality Standards…” The permit also includes new requirements for MS4
that are subject to a TMDL. These requirements include developing a TMDL Assumptions and
Requirements Attainment Plan (ARAP) that includes, among other things, a process to identify
specific BMPs to address TMDL pollutants, prioritized actions, and an implementation schedule.
STRUCTURAL BACTERIA AND NUTRIENT BMP EVALUATION
Structural BMPs Evaluated
MSD requires new and redevelopment projects to submit a Stormwater Management Facilities
BMP Operation and Maintenance Design Report and Plan for approval. According to MSD’s
Small MS4 2015-16 Annual Report (Annual Report), since implementation of these new water
quality BMP requirements in October 2006, 1,286 projects representing 4,516 BMPs have been
constructed, permitted for construction, or are under review by MSD’s Planning Division.
According to the Annual Report, bioretention (48%) was by far the most common BMP
implemented (Figure 1).
Bacteria and Nutrient BMP Strategy Review
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Figure 1. Post-Construction BMPs Built, Permitted for Construction, or Under Review as of 6/16/2016 (from the
Annual Report). Of the 4,516 BMPs, nearly half were bioretention
In addition to the structural BMPs identified in the Annual Report (Figure 1), this evaluation
included three common Post-Construction Ordinances: stream buffers, tree preservation, and
impervious area reduction. Also, two advanced structural BMPs designed specifically for
treating bacteria and nutrients were evaluated. These advanced structural BMPs included
enhanced biofilters 3 and subsurface flow wetlands 4.
3 Enhanced biofilters are defined here as vegetated media filters (or bioretention with underdrains) that incorporate
the following design enhancements that have been shown to improve bacteria reduction relative to standard
biofilters:
• Media amendments such as biochar and coconut coir that have been shown to enhance bacteria removal;
• Vegetation that is shown to enhance bacteria removal and support media aeration while reducing potential for
short circuiting or underdrain clogging;
• Outlet control for enhanced contact time; and
• A saturated zone. 4 Subsurface flow wetlands are engineered, below-ground horizontal flow treatment wetlands that include many of
the natural treatment processes of surface flow constructed wetlands as well as the filtration mechanisms of media
filters. Water flows through a granular matrix, which typically supports the growth of emergent wetland vegetation
on the surface.
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Relative Benefit Rankings for Structural BMPs
To evaluate bacteria and nutrient reduction effectiveness of ongoing structural BMP
implementation, the BMP categories were compared using a relative scoring system based on
weighting factors derived from previous BMP implementation planning experience, along with
feedback from MSD. Table 1 identifies the weighting applied to each benefit category and
briefly describes the approach to score the BMPs.
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Table 1. Approach for Scoring and Weighting Benefits.
Benefit
Group Benefit Category Weighting Scoring Approach
Target
Pollutant
Benefits
E. Coli Treatment 30% First, benefits from pollutant concentration reductions will
be calculated based on median effluent concentrations from
the International Stormwater BMP database5, along with
statistical results showing whether the removal was
significant (e.g. non-parametric hypothesis tests, either the
Mann-Whitney rank sum test or the Wilcoxon signed-rank
test). Then these scores will be modified to include the
pollutant reductions resulting from volume reduction.
Nitrite (NO2) and
Nitrate (NO3)
Nitrogen
Treatment
15%
Total Phosphorus
Treatment 15%
Additional
Benefits
Other Water
Quality Parameter
Treatment
15%
Based on significant reduction of other important water
quality parameters (e.g., total suspended solids, metals,
chloride) as reported in the Boston BMP Guidance
Document 6.
Flood
Management 10%
The relative ability to decrease flood risk by reducing peak
flow rates and/or volume reduction based on the Boston
BMP Guidance Document.
Habitat/
Environmental
Improvements
7%
Improvement and protection of wetland and riparian
enhancement/ creation evaluated by best professional
judgment.
Community
Enhancements 8%
Based on three factors: (1) Enhancement/creation of
recreational and public use areas, (2) Educational
opportunities, or (3) Aesthetic benefits evaluated by best
professional judgment.
Since the focus of this memorandum is evaluating BMP selection based on water quality
performance for bacteria and nutrients, benefits associated with the treatment of those target
pollutants were grouped and assigned the highest weighting factor. Because there are TMDLs
already in effect for bacteria in the St. Louis area, the E. coli weighting factor was higher than
the nutrients factor. The scoring of target pollutant benefits was performed quantitatively based
on the measured inflow and outflow concentrations for all BMPs that met data quality and
5 Geosyntec Consultants, Inc., Wright Water Engineers, Inc., International Stormwater BMP Database,
Manufactured Devices Performance Summary Report. July 2012. and International Stormwater Best Management
Practices (BMP) Database Pollutant Category Statistical Summary Report Solids, Bacteria, Nutrients, and Metals
http://www.bmpdatabase.org/ 6 Boston Water and Sewer Commission, Stormwater Best Management Practices: Guidance Document, prepared by
Geosyntec Consultants. January 2013.
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quantity criteria 7 from the International Stormwater BMP Database5. The scoring guidance for
the target pollutants is defined in Table 2. The analysis of the target pollutant benefits and the
benefit score for each post-construction structural BMP/Target Pollutant combination8 is
reported in Table A-1.
Table 2. Target Pollutant Benefit Scoring Guidance for Water Quality Benefits for BMPs.
Score Target Pollutant Benefit
3 High pollutant removal
2 Medium pollutant removal
1 Low or no pollutant removal
In addition to treating stormwater for the target pollutants, the BMPs were evaluated for other
benefits (Table A-2). These other benefits included: 1) reduction of other important water quality
parameters (e.g., TSS/sediments and metals), 2) ability to decrease flood risk by reducing peak
flow rates and/or volume reduction, 3) improvement and protection of wetland and riparian
enhancement/creation, and 4) community enhancements and opportunities. The weighting
factors for these additional benefits reflect their relative significance to MSD, while still
recognizing the important benefits that they could provide. The scoring of the additional benefits
was performed qualitatively based on the Boston BMP Guidance Document and best
professional judgment as defined in Table 3. The analysis of the additional benefits and the
benefit score for each BMP/additional benefit combination is reported in Table A-2.
7 To be included in this category-level summary, at least three BMP studies must be included in the BMP category,
with each BMP study having influent and effluent data for at least three storms for the pollutant of interest. 8 Post-construction ordinances and advanced structural BMPs do not have reported effluent concentrations in the
International Stormwater BMP database and therefore were not included in the Table A-1 analysis.
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Table 3. Scoring Guidance for Additional Benefits of BMPs.
Score Other Water
Qualitya Flood Management Habitat/
Environmental Communityb
3
High in both
sediment and
metals reduction
High volume and
peak flow reduction
Significant
portion of BMP
creates habitat
BMP provides high potential
for all two to three
community benefits
2
Medium sediment
and metals
reduction
Medium volume and
peak flow reduction
Some portion of
BMP creates
habitat
BMP provides medium
potential for two community
benefits
1
Low or no
sediment and
metals reduction
Low or no volume
and peak flow
reduction
Small amount or
no of habitat
created
BMP provides low or no
potential for two community
benefits
a. Chloride was also considered for evaluation in the “Other Water Quality” category; however, only
limited performance data exists for chloride and little or negative removal is shown for those BMPs
with data. Therefore, chloride was excluded in the scoring. b. Community benefits include enhancement/creation of public use areas; educational opportunities;
and community aesthetics.
Scores for each benefit category, as described above, were multiplied by their weighting factors
(Table 1) and a combined benefit score for each BMP 9 was calculated and reported in Table A-3.
The BMPs were then ranked according to their scores and the results are summarized in Table 4.
9 This table also includes scores for target pollutant benefits for post-construction ordinances and advanced
structural BMPs based on expected performance relative to similar BMP types determined using best professional
judgment.
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Table 4. Distribution of BMPs Used within the MSD Service Area and Benefits Ranking.
Rank BMP Score
% of BMPs
Built or
Planned
1 Infiltration BMPs 2.9 1%
2 Subsurface Flow Wetlands 2.8 NA
3 Ponds 2.6 1%
4 Enhanced Biofilters 2.5 NA
5 Bioretention 2.4 48%
5 Permeable Pavement 2.0 18%
7 Surface Sand Filters 1.8 0.04
8 Underground Sand Filters 1.8 1%
9 Underground Manufactured Filters 1.5 0.01
10 HDS Units 1.5 6%
11 Cisterns 1.4 0.01
12 Impervious Area Reduction 1.4 NA
13 Engineered Swales 1.3 4%
14 Tree Preservation Ordinance 1.2 NA
14 Stream Buffer 1.2 NA
Relative Cost Rankings for Structural BMPs
To provide estimates of the local capital and annual maintenance costs of the post-construction
structural BMPs and evaluate the relative cost ranking for the post-construction structural BMPs
and ordinances and advanced structural BMPs, the following cost analysis was conducted. The
cost estimations presented in this section are based on estimates of probable capital and
maintenance costs per capture (treatment) of runoff from one acre of drainage area. The costs
were computed by developing a cost estimation procedure that uses unit cost information from
literature for capital and maintenance costs to create curves (cost per volume treated translated
into cost per tributary area treated) for stormwater BMPs. Example unit cost items include:
• Mobilization
• Demolition
• Clearing & Grubbing
• Dewatering
• Excavation
• Haul/Dispose of Excavation Material
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• Rough and Finished Grading
• Pipe Material (primarily underdrain)
• Soil Media / Planting Media
• Other Bulk Material (pea gravel,
clean-washed gravel, base course
gravel and bedding material)
• Pavement/Concrete/Curbs
• Mulch
• Vegetation
Because there are many factors that affect the capital costs of structural BMPs besides the
treatment volume, such as development type (new development, redevelopment, retrofit), native
soil infiltration rate, site slope, pretreatment requirements, existing infrastructure, and large
event/overflow safety, a range of costs is included as part of the cost estimation. While the costs
for the effort were calculated on a national scale using literature and bid tabs from across the
country, an approach was developed using Bureau of Labor Statistics data for stormwater
construction equipment, material and labor to tailor estimated costs to the St. Louis region. Other
factors that can often influence costs such as: land acquisition, project purpose (e.g.,
demonstration project), regulatory and permitting requirements, utility conflict resolution,
design, union/non-union rates, and level of experience of designers and contractors were not
included as a part of the cost estimation. The three-step cost estimation approach is briefly
summarized below as follows:
• Step 1: Size BMPs – assume a 1-acre drainage area and use the 1.14-inch design storm
for the study area to compute the design volume of runoff required for each BMP for a 1-
acre residential (typically low estimate because of lower impervious surface density) and
1-acre commercial lot (typically higher estimate because of greater impervious surface
density requiring a larger treatment volume and therefor larger treatment facility).
• Step 2: Apply Cost Curve –determine cost curves function for each scenario and obtain
low/high cost estimation range for BMPs to meet design requirements. Report cost
estimate as a range comprised of the low residential estimate (assumed to be 35% site
imperviousness) and the high commercial estimate (assumed to be 65% site
imperviousness) to effectively bracket costs. Of note, if impervious density is greater,
than a higher cost would be needed to capture and treat the associated design volume.
• Step 3: Apply Cost Regionalization and Inflation Adjustment – Convert national
itemized unit cost estimates from RS Means, built projects, bid tabs, and other data
sources, using stormwater construction specific regional cost adjustment factor based on
Bureau of Labor Statistics data for St. Louis from Step 1. An inflation adjustment factor
was applied as needed to obtain 2015 estimates (the most recent complete year for
Bureau of Labor Statistics data).
The result of applying the three-step cost estimation approach is shown in Table 5.
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Table 5 Estimates of Probable BMP Construction and Maintenance Costs per Acre of Drainage Area Treated.
Post-Construction BMPS
Initial Capital Cost Estimate
Range*
(Treatment for a 1-acre site)
Annual Maintenance Cost
Estimate Range
(Per System)
Low High Low High
Bioretention $ 10,800 $ 25,400 $ 900 $ 4,000
Infiltration BMPs $ 4,800 $ 29,000 $ 700 $ 4,400
Engineered Swales $ 3,500 $ 17,600 $ 200 $ 1,300
Permeable Pavement $ 8,200 $ 27,600 $ 800 $ 3,100
Cisterns $ 12,400 $ 21,600 $ 200 $ 700
Ponds $ 9,000 $ 30,800 $ 700 $ 4,900
Surface Sand Filters $ 14,400 $ 38,800 $ 900 $ 3,200
Underground Sand Filters $ 17,000 $ 50,200 $ 1000 $ 3,700
Underground Manufactured
Filters $ 12,200 $ 39,300 $ 1,100 $ 4,600
HDS Units $ 14,100 $ 42,200 $ 1,000 $ 3,700
*Cost curves are not on a per acre basis as many costs are necessary for the first unit of BMP.
Subsequent/additional costs may not be linear and may not have a one to one relationship with area.
Approximate volume of treatment for the 1-acre site was about 1,450-2,700 ft3. Sizing for cost
estimation is based on an assumed volumetric capture (about one inch) but does not include achieving a
required level of performance.
To rank the structural BMPs, the average capital and maintenance costs were computed and
BMPs were ranked and placed into tiers representing similar costs between BMPs. The relative
capital cost and maintenance scores for each BMP were assessed for an estimated 20-year life
cycle cost to capture the long-term maintenance cost estimates along with initial capital costs.
The BMPs were then ranked according to their scores. The results are summarized in Table 6.
A lack of data on post-construction ordinances and the advanced structural BMPs resulted in
these management strategies receiving no cost score to prevent comparison and potential biases
between BMPs of known and unknown costs.
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Table 6 Rankings Based on Estimates of Probable Capital and Maintenance Costs
Tier BMP
Estimated Cost
Score
1
Engineered Swales 3.0
Cisterns 2.5
Bioretention 2.4
Infiltration BMPs 2.4
Ponds 2.3
Permeable Pavement 2.2
2
Underground Manufactured
Filters 1.6
Surface Sand Filters 1.6
HDS Units 1.4
Underground Sand Filters 1.0
3
Stream Buffer NA
Tree Preservation Ordinance NA
Impervious Area Reduction NA
Enhanced Biofilters NA
Subsurface Flow Wetlands NA
Not applicable (NA) was assigned to BMPs that did not have available cost
information.
Site-Specific Considerations for Using Structural BMP Rankings
An important component of post-construction runoff control programs, relative to the iterative
process of removing pollutants to the MEP, is the process for accounting for site-specific
feasibility issues and constraints. This issue is typically addressed in BMP technical guidance
manuals for new and redevelopment (and possibly in stormwater ordinances as well), and each
MS4 permittee or jurisdiction may choose to exercise their authority and level of
prescriptiveness differently. As one example, the Orange County Technical Guidance
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Document 10 establishes detailed infeasibility criteria for each BMP type. Below are some very
basic infeasibility criteria examples and their implications for BMP suitability relative to the
BMP ranking established herein:
• Infiltration constraints (e.g., tight soils and shallow bedrock or groundwater that would
prohibit infiltration based options) – At sites where such constraints exist, ponds,
subsurface flow wetlands, and enhanced biofilters are treatment-only BMPs that are
acceptable alternatives based on demonstrated pollutant removal performance.
• Limited space for BMP footprint (e.g., steep slopes within the site) – In this case,
permeable pavement is an acceptable and effective option to retain/treat stormwater
where the BMP area is incorporated into the development footprint. Also, enhanced
biofilters typically have a larger treatment capacity (i.e., can be built smaller, while still
treating the same design flowrate or volume) than similarly sized, higher ranked BMPs.
• Large design volumes requiring treatment (e.g., significant impervious area within the
site) – This constraint could make some BMP types infeasible unless implemented in
combination with others (e.g., large cisterns may be impractical). In general, project
applicants should be encouraged to consider the benefits of BMP combinations (e.g.,
treatment trains, distributed BMPs), where appropriate.
Finally, and related to both MEP and necessary components of any BMP technical guidance
manual, since this BMP ranking evaluation assumed all BMP types are sized the same, clear
design storm guidance should accompany any BMP selection guidance that is provided to project
applicants.
NON-STRUCTURAL BACTERIA AND NUTRIENT BMP EVALUATION
To better understand the extent to which non-structural BMPs are currently being implemented
to target bacteria and nutrients, stormwater program managers from MSD and seven other MS4
communities were surveyed. These communities were selected based on their geographic
distribution and ease of obtaining information. Furthermore, although MSD is a Phase II MS4,
both Phase I and II communities were included in the survey. Both Phase I (large) and II (small)
systems were surveyed since MSD’s stormwater system is more comparable in size to Phase I
communities; however, it is controlled under Phase II regulations and permit requirements. The
number of MS4 communities surveyed in each EPA region included:
10 County of Orange, 2013. Technical Guidance Document (TGD) for the Preparation of Conceptual/Preliminary
and/or Project Water Quality Management Plans (WQMPs). December 20, 2013.
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• MSD (EPA Region 7 – Phase II Community)
• EPA Region 7 – Phase I Community (2)
• EPA Region 7 – Phase II Community (1)
• EPA Region 4 – Phase I Community (1)
• EPA Region 4 – Phase II Community (1)
• EPA Region 5 – Phase II Community (2)
Program managers were presented with a list of potential bacteria and nutrient BMPs that could
be implemented under each of the six MCMs required by Phase II MS4 regulations. These BMPs
were developed from suggestions presented in the literature 11 and best professional judgment
(see Table A-5 for the list of BMPs). Program managers were asked to identify BMPs from the
list that are currently being applied within their system. It should be noted that the list of BMPs
was not intended to be all-encompassing. Rather, it reflects those BMPs most commonly
considered to be effective for managing bacteria and nutrients
For those BMPs being applied, the managers were then asked to qualitatively assess the degree
to which each is implemented using the following categories:
• High (green) – BMP is used with active management, measurement, or tracking.
• Medium (yellow) – BMP implemented but with limited measurement or tracking
measurement.
• Low (red) – BMP implemented intermittently but few to no measurements or tracking.
• None (blank) – BMP unused or unknown.
To assist in making meaningful comparisons between the qualitative assessment results, each
community response was converted to a relative score (high = 3, medium = 2, low = 1, none =
0). Converted response scores were then summed and standardized for each BMP category to
develop a normalized implementation score that ranges from 0 to 1. The normalized
implementation scores serve to represent the degree to which each BMP is implemented across
the surveyed communities. For a given BMP category, values near 0 indicate that few of the
surveyed communities use the BMP with limited implementation; values near 1 indicate that
most surveyed communities use the BMP with active implementation. For this evaluation,
normalized community scores were interpreted using the following scale:
11 Urban Water Resources Research Council (UWRRC). 2014. Pathogens in Urban Stormwater Systems.
Environmental and Water Resources Institute. American Society of Civil Engineers.
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• Less than or equal to 0.4 – Limited implementation. The BMP may not be applicable to
or appropriate for many communities. MSD should generally consider them to be low
priority BMPs.
• Between 0.4 and 0.6 – Moderate implementation. The BMP is commonly used and
should be considered for MSD’s program, if applicable.
• Greater than 0.6 – High implementation. The BMP is commonly used in most
communities. MSD should generally consider these to be high priority BMPs and identify
opportunities to include within the stormwater program.
Results of the evaluation show that the implementation of non-structural bacteria and nutrient
BMPs varies between MCMs and across the surveyed communities (Figure 2). In general, BMPs
under MCMs #1 (public education and outreach) and #6 (pollution prevention and good
housekeeping) have limited implementation, with several BMPs scoring between 0 and 0.4 for
all of the communities. The primary exceptions to this limited implementation are pet waste and
fertilizer outreach programs under MCM #1. In contrast, many BMPs under MCMs #3 (illicit
discharge detection and elimination) and #5 (post-construction stormwater management) have
scores between 0.6 and 1, indicating that these BMPs are generally implemented actively by all
of the communities. Results from MCM #2 (public involvement and participation) suggest that
most BMPs are consistently but moderately implemented by the communities (scores of 0.4 to
0.6).
The community survey scores were compared to those from MSD’s program to evaluate the
District’s current progress relative to other established programs and identify potential areas for
future enhancement. An overview of results for MSD’s stormwater program relative to the
surveyed communities for each MCM is included below. An overview of results for MSD’s
program relative to the surveyed communities for each MCM is included below.
• MCM #1 – Public Education and Outreach: Most BMPs are implemented to a limited
degree (score of less than 0.4) across the surveyed communities. Similarly, MSD does not
use many of the BMPs that were reviewed. With the exception of fertilizer outreach
efforts, BMPs that MSD does apply are implemented more actively relative to the other
MS4s.
• MCM #2 – Public Involvement and Participation: With the exception of downspout
disconnection and site designs (BMP 2.7), BMPs under this MCM are at least moderately
implemented across the communities. MSD implements most of the BMPs to a
comparable or greater degree than the other communities.
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• MCM #3 – Illicit Discharge Detection and Elimination: In general, these BMPs are
highly implemented across the communities. MSD implements a majority of BMPs under
this MCM to a comparable or greater degree than the other communities.
• MCM #4 – Construction Site Stormwater Runoff Control: MSD’s implementation of
the two BMPs reviewed under this MCM are generally comparable to the other
communities.
• MCM #5 – Post-Construction Stormwater Management: BMPs under this MCM are
actively implemented across the communities. MSD implements a majority of BMPs to a
comparable or greater degree than the other communities.
• MCM #6 – Pollution Prevention and Good Housekeeping: Implementation of BMPs
under this MCM was mixed across the surveyed communities. The BMPs that MSD does
apply are generally implemented more actively relative to the other communities.
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Figure 2. Summary of Non-Structural Bacteria and Nutrient BMP MS4 Community Survey Results. Normalized
implementation scores were calculated based on the degree to which each BMP is implemented across the
surveyed communities. For a given result, values near 0 indicate that few communities use the BMP with limited
implementation; values near 1 indicate that most communities use the BMP with extensive implementation. For
BMP identification numbers, refer to the community survey results in Table A-5.
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As MSD investigates enhancements to their stormwater programs over time, program managers
should initially focus on evaluating high priority (scores greater than 0.6) BMPs from the
community survey that are either not widely used or currently have limited implementation in the
St. Louis area. These include a using a public reporting tool (BMP 3.6), improving existing
septic system inventory activities (BMP 3.8), and increasing street sweeping frequency (BMP
6.8).
Once high priority BMPs have been addressed, MSD should review the moderately-implemented
(scores of 0.4 – 0.6) community survey BMPs to determine if they can be used or improved.
These BMPs include:
• Conducting private fertilizer education programs (BMP 1.3),
• Creating a tree sale program (BMP 2.2),
• Increasing the number and accessibility of public trash cans and pet waste stations (BMP
2.6),
• Improving baseflow source identification practices (BMP 3.1),
• Conducting instream algae monitoring (BMP 3.10),
• Improving construction site runoff control procedures on small sites (BMP 4.2), and
• Establishing a septic system elimination program (BMP 3.9).
MSD has recently worked to eliminate some septic systems in the St. Louis City and County area
as part of their Sewer Connection and Septic Tank Closure Program. Funding for this program
included a one-time allocation of approximately $2 million from MSD’s Project Clear. MSD and
their co-permittees should review the efficacy of the recent elimination program and determine
its viability as a permanent BMP going forward.
BMPs identified as having limited implementation in the community survey should be
considered a low priority for potential incorporation into MSD’s stormwater management
program. These BMPs should be reviewed over time as resources permit.
Other Considerations that Affect MEP for Non-Structural BMPs
While it is useful to understand MCM implementation by other MS4 communities across the
country to help establish what MEP is, MEP is also established in part by standard guidance. For
example, in ASCE’s Pathogens in Urban Stormwater Systems 12 report and presentations, it is
12 Urban Water Resources Research Council (UWRRC). 2014. Pathogens in Urban Stormwater Systems.
Environmental and Water Resources Institute. American Society of Civil Engineers.
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noted that non-structural BMP selection should be agency-specific (and thus not be designed to
precisely match the actions of other communities) and based on local sources. Local sources of
nutrients and bacteria should first be identified based on existing available GIS and monitoring
data, local knowledge and observations, and special studies. Then sources should be prioritized
based on risk level (e.g., human waste presents a greater illness risk than non-human and non-
fecal bacteria, certain forms of nutrients are more bioavailable or controlling in the
eutrophication process), and controllability. Once local sources are prioritized, then non-
structural source control BMPs should be selected to specifically target the highest priority
sources. This process, as documented through nationwide guidance, further helps to establish the
MEP.
An example process for bacteria is described here. Bacteria sources are typically ubiquitous in
the urban environment and numerous sources could contribute to excessive levels in urban
waterbodies. Therefore, a list of general urban sources and identification of non-structural BMPs
to address these typical sources would likely be too broad to develop a tailored non-structural
BMP program for each subwatershed or MS4 community. Guidance for identifying
subwatershed or MS4 community-specific bacteria sources can be found in the ASCE
publication, Pathogens in Urban Stormwater Systems, including:
• GIS mapping and analysis of infrastructure and analysis of monitoring data to identify
potential problem areas;
• Meeting with field staff and others with experience in the subwatershed to compile their
local knowledge;
• Subwatershed-specific observations;
• Enhanced illicit discharge detection and elimination (IDDE) investigations of MS4,
including microbial source tracking and traditional tools (e.g., CCTV and dye testing).
This source inventory could then be categorized and prioritized based on controllability and
public health risk, with human, non-human, and non-anthropogenic sources representing high,
medium, and low risk categories, respectively. Then non-structural BMPs could be selected to
effectively target the high and medium risk categories as comprehensively as possible and as
available funding allows. The ASCE pathogen publication provides examples of cost-effective
potential BMPs that may be considered based on the source identification findings, including:
• Sewer repairs where enhanced IDDE investigations have shown wastewater collection
systems leaking into the MS4
• Education/outreach to residential homeowners on limiting fertilizer application
• Improved prevention/housekeeping practices to limit fertilizer use by municipal
operations
• Pet waste disposal ordinances in areas of high pet density.
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Ultimately it may be more effective to aggressively implement a fewer number of BMPs that are
targeted to highest priority sources than to attempt to match the level of BMP implementation of
most other MS4 communities. For example, while resource intensive, septic inspection/inventory
and illicit connection detection are two of the most important BMPs for controlling human waste
and pathogens. MSD is implementing these BMPs at a “medium” or lower level. With increased
resources, efforts could be focused in high priority areas to better match the state of the practice
as documented in available nationwide guidance.
SUMMARY AND NEXT STEPS
Several new state regulatory requirements will impact how MSD administers their stormwater
management program. These new requirements will require MSD to evaluate and identify BMPs
that reduce bacteria and nutrients in stormwater runoff to the MEP. To assist MSD in
characterizing MEP for bacteria and nutrient, MSD’s existing structural and non-structural BMPs
were evaluated relative to the state of the practice and other MS4 programs. Significant findings
from this evaluation include the following:
• The top ranked structural BMPs (with a combined cost and benefit score above 4, as
shown in Table 7) were those that reduce runoff volume through infiltration or capture or
had advanced flow through designs. Few flow-through structural BMPs have effluent
concentrations that consistently meet water quality criteria for bacteria and nutrients
(only ponds).
• Approximately 70% of the built or planned structural BMPs in the MSD MS4 area are
ranked in the top three for benefits and have average scores (approximately 2) for costs.
• Post-construction ordinances and very basic structural BMPs were top ranked based on
costs, however these BMPs provided only minimal benefits.
• The treatment structural BMPs that incorporate advanced design characteristics (e.g.,
subsurface flow wetlands and enhanced biofilters) provide top ranked benefits, however,
their poor costs rankings can be prohibitive for some implementation scenarios.
• Site-specific feasibility issues and constraints can dramatically affect the performance
and costs of BMP types and should be considered early in the planning process.
• Going forward, MSD should focus on evaluating high priority (scores of greater than 0.6)
BMPs from the community survey that are either not widely used or currently have
limited implementation in the St. Louis area. Once high priority BMPs have been
addressed, MSD should review the moderately-implemented (scores between 0.4 and 0.6)
community survey BMPs to determine if they can be used or improved. Community
survey BMPs with limited implementation (scores less than 0.4) should be reviewed as
resources become available.
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• A comprehensive source identification and prioritization process directing the
implementation of non-structural BMPs can dramatically affect the effectiveness and
efficiency of the program.
Table 7 Benefits and Estimates of Probable Capital and Maintenance Costs
BMP
Estimated Benefits
Score
(Out of 3)
Estimated Cost
Score
(Out of 3)
Infiltration BMPs 2.9 2.4
Subsurface Flow Wetlands 2.8 NA
Ponds 2.6 2.3
Enhanced Biofilters 2.5 NA
Bioretention 2.4 2.4
Permeable Pavement 2.0 2.2
Surface Sand Filters 1.8 1.6
Underground Sand Filters 1.8 1
Underground Manufactured Filters 1.5 1.6
HDS Units 1.5 1.4
Cisterns 1.4 2.5
Impervious Area Reduction 1.4 NA
Engineered Swales 1.3 3.0
Stream Buffer 1.2 NA
Tree Preservation Ordinance 1.2 NA
Not applicable (NA) was assigned to BMPs that did not have available cost information.
Results of this evaluation can be used to help review the MSD BMP Toolbox
(http://www.stlmsd.com/what-we-do/stormwater-management/bmp-toolbox) and identify
potential areas to enhance BMP implementation. Some preliminary examples include:
• Highlighting the importance of implementing BMPs that focus on bacteria and nutrient
reduction.
• Providing guidance for the selection of BMPs capable of achieving bacteria and nutrient
reduction given site-specific conditions (e.g., land use, space constraints, rainfall patterns,
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etc.) or identified sources (e.g., residential and municipal over-fertilization, dumpsters,
washdown and grease traps at food outlets).
• Providing additional BMP design guidance related specifically to bacteria and nutrient
removal including:
o Vegetation selection
o Outlet controls/contact time guidance
o Media selection and specification
o Removal of compost/alternative soil amendments (a source of nutrients)
o Incorporation of saturated zone for bacteria and/or nitrogen removal
o Incorporation of an activated alumina layer for phosphorus removal
o Other pertinent design information based on findings from literature
*****
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ATTACHMENT A
BMP EVALUATION RESULTS
MSD Structural BMP Evaluation
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Table A-1. Benefit Scores for Each Structural Best Management Practice (BMP)/Target Pollutant Combination
E. Coli Treatment Nitrite (NO2) + Nitrate (NO3) as
Nitrogen Treatmentd Total Phosphorus Treatment
Post-Construction Structural
BMPs BMP Database Category
Median Effluent
Concentration
(colonies /100ml)
Statistically
Significant
Removal (Y/N)
Score
Median
Effluent
Concentration
Statistically
Significant
Removal
(Y/N)
Score
Median
Effluent
Concentration
Statistically
Significant
Removal
(Y/N)
Score
(mg/L) (mg/L)
Bioretention Bioretention 101 Y 3 0.37 N 1 0.24 N 1
Infiltration BMPs Not Available Not Available 3 Not Available 3 Not Available 3
Engineered Swales Biofilter - Grass Swale 4,182 N 1 0.22 N 1 0.171 N 1
Permeable Pavement Porous Pavement Not Available 3 1.35 N 3 0.1 Y 3
Cisterns Not Available Not Available 1 Not Available 1 Not Available 1
Ponds Retention Pond 100 Y 3 0.13 Y 2 0.091 Y 2
Surface Sand Filters Media Filter 420a Y 2 0.57 N 1 0.089 Y 2
Underground Sand Filters Media Filter 420a Y 2 0.57 N 1 0.089 Y 2
Underground Manufactured
Filters Manufactured Device - Filtration 910b N 1 0.29c N 1 0.06 Y 2
HDS Units Manufactured Device - Physical 910b N 1 0.36c Y 2 0.22 Y 2
a. The International Stormwater BMP Database does not have sufficient data for Media Filter E. coli effluent concentrations; therefore, the reported fecal coliform was evaluated.
b. The BMP Database does not have sufficient data for Manufactured Devices (Filtration and Physical) E. coli effluent concentrations; therefore, the reported fecal coliform was evaluated.
c. The BMP Database does not have sufficient data for Manufactured Devices (Filtration and Physical) NO2 + NO3 as Nitrogen effluent concentrations; therefore, NOx as Nitrogen was evaluated.
d. NO2 + NO3 as Nitrogen was evaluated since it had the most results in the BMP Database.
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Table A-2. Additional Benefit Scores for Each BMP/Targeted Benefit Combination
Other Water Quality Treatment Flood Management Habitat / Environmental Community Enhancements
Post-Construction Structural BMPs Sediment
Reduction
Metals
Reduction Score Volume
Reductiona
Peak Flow
Reduction Score Habitat
Creation Score
Enhancement/
Creation of Public
Use Areas
Educational
Opportunities
Community
Aesthetics Score
Bioretention High High 3.0 High Medium 2.5 High 3.0 High High High 3.0
Infiltration BMPs High High 3.0 High High 3.0 Medium 2.0 Medium High Medium 2.3
Engineered Swales Medium Medium 2.0 Low Low 1.0 Medium 2.0 Medium Medium Medium 2.0
Permeable Pavement Medium Medium 2.0 Medium Medium 2.0 Low 1.0 Low Medium Low 1.3
Cisterns High Medium 2.5 High Medium 2.5 Low 1.0 Low Medium Medium 1.7
Ponds High High 3.0 Low High 2.0 High 3.0 High High High 3.0
Surface Sand Filters High High 3.0 Low Low 1.0 Low 1.0 Low Medium Low 1.3
Underground Sand Filters High High 3.0 Low Low 1.0 Low 1.0 Low Low Low 1.0
Underground Manufactured Filters High High 3.0 Low Low 1.0 Low 1.0 Low Low Low 1.0
HDS Units Medium Medium 2.0 Low Low 1.0 Low 1.0 Low Low Low 1.0
Post-Construction Ordinances
Stream Buffer Medium Medium 2.0 Low Medium 1.5 High 3.0 High Medium High 2.7
Tree Preservation Ordinance Low Low 1.0 Medium Low 1.5 High 3.0 High Medium High 2.7
Impervious Area Reduction Medium Medium 2.0 Medium Medium 2.0 Medium 2.0 High Low Medium 2.0
Advanced Structural BMPs
Enhanced Biofilters (e.g., Bioretention
with underdrains) High High 3.0 Medium Medium 2.0 High 3.0 Medium High High 2.7
Subsurface Flow Wetlands High High 3.0 Medium Medium 2.0 High 3.0 High High High 3.0
a. It is assumed that all the BMPs are sized to treat the same design storm (e.g., bypass from a flow through BMP such as engineered swales, sand filter, pond, etc. would be as frequent as from a retention BMP such as bioretention, infiltration
basin, etc.). For this reason, both bioretention and cisterns are assumed to have high volume reduction.
MSD Structural BMP Evaluation
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Table A-3. Summary of Structural BMP/Benefit Scoring
Target Pollutant Benefitsa Additional Benefits
E. Coli
Total
Nitrogen
Total
Phosphorus
Other
Water
Quality
Flood
Management
Habitat/
Environmental
Community
Enhancements Total Score Rank
(out of 15)
Weighting 30% 15% 15% 15% 10% 7% 8% 100%
Post-Construction Structural
BMPsb
% of BMPs Built
or Planned 1-3 1-3 1-3 1-3 1-3 1-3 1-3 3
Bioretention 48% 3.0 1.0 1.0 3.0 2.5 3.0 3.0 2.4 5
Infiltration BMPs 1% 3.0 3.0 3.0 3.0 3.0 2.0 2.3 2.9 1
Engineered Swales 4% 1.0 1.0 1.0 2.0 1.0 2.0 2.0 1.3 13
Permeable Pavement 18% 3.0 1.0 2.0 2.0 2.0 1.0 1.3 2.0 6
Cisterns 1% 1.0 1.0 1.0 2.5 2.5 1.0 1.7 1.4 11
Ponds 1% 3.0 2.0 2.0 3.0 2.0 3.0 3.0 2.6 3
Surface Sand Filters 4% 2.0 1.0 2.0 3.0 1.0 1.0 1.3 1.8 7
Underground Sand Filters 1% 2.0 1.0 2.0 3.0 1.0 1.0 1.0 1.8 8
Underground Manufactured Filters 1% 1.0 1.0 2.0 3.0 1.0 1.0 1.0 1.5 9
HDS Units 6% 1.0 2.0 2.0 2.0 1.0 1.0 1.0 1.5 9
Total systems install on new or
redevelopment since 2006 4,516
Post-Construction Ordinances
Stream Buffer NA 1.0 1.0 1.0 2.0 1.0 3.0 3.0 1.2 15
Tree Preservation Ordinance NA 1.0 1.0 1.0 1.0 1.0 3.0 2.0 1.2 14
Impervious Area Reduction NA 1.0 1.0 1.0 2.0 2.0 2.0 2.0 1.4 12
Advanced Structural BMPs
Enhanced Biofilters NA 3.0 1.0 3.0 3.0 1.0 3.0 3.0 2.5 4
Subsurface Flow Wetlands NA 3.0 3.0 3.0 3.0 1.0 3.0 3.0 2.8 2
a. BMPs with high volume reduction (see the Flood Management category in Table A-2) have a target pollutant benefit of 5. For BMPs with medium volume reduction have 1 point added to each
target pollutant effluent concentration score
b. The permitted structural BMP "storm credits" and "other" are not included in the BMP scoring because of the variety of approaches used in each of those categories
MSD Structural BMP Evaluation
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Table A-4. Summary of Structural BMP/Cost Scoring
Initial Capital Cost Estimate Rangea Annual Maintenance Cost Estimate Range Averaged
Score
(out of 3)
Rank
(out of 10) (Treatment for a 1-acre site) (Per System)
Post-Construction Structural
Controls Low High Average Low High Average
Bioretention $7,800 $25,400 $16,600 $4,000 $2,450 $19,050 2.4 3
Infiltration BMPs $4,800 $29,000 $16,900 $4,400 $2,550 $19,450 2.4 4
Engineered Swales $3,500 $18,700 $11,100 $1,300 $750 $11,850 3.0 1
Permeable Pavement $8,200 $27,600 $17,900 $3,100 $1,950 $19,850 2.3 5
Cisterns $12,400 $21,600 $17,000 $800 $500 $17,500 2.5 2
Ponds $9,000 $26,900 $17,950 $4,500 $2,600 $20,550 2.3 6
Surface Sand Filters $14,400 $38,800 $26,600 $3,200 $2,050 $28,650 1.6 8
Underground Sand Filters $16,200 $50,200 $33,200 $3,700 $2,350 $35,550 1.0 10
Underground Manufactured
Filters $12,200 $39,300 $25,750 $4,600 $2,850 $28,600 1.6 7
HDS Units $14,100 $42,200 $28,150 $3,700 $2,350 $30,500 1.4 9
Post-Construction Ordinancesb
Stream Buffer NA NA
Tree Preservation Ordinance NA NA
Impervious Area Reduction NA NA
Advanced Structural Controlsb
Enhanced Biofilters NA NA
Subsurface Flow Wetlands NA NA
a. Cost curves are not on a per acre basis as many costs are necessary for the first unit of BMP. Subsequent/additional costs may not be linear and may not have a one to one
relationship with area. Approximate volume of treatment for the 1-acre site was about 1450-2700 ft3. Sizing for cost estimation does not include achieving a required level
of performance.
b. Cost estimates were not available for post-construction ordinances or advanced structural BMPs, therefore relative costs were assigned using best professional judgment.
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Table A-5. Non-Structural Bacteria and Nutrient Best Management Practice (BMP) MS4 Community Survey Results.