November 28, 2023 - Boston Water and Sewer Commission

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Boston Water and
Sewer Commission 
980 Harrison Avenue
Boston, MA 02119-2540
Tel: (617) 989-7366
Fax: (617) 989-7736 
November 28, 2023 
VIA ELECTRONIC MAIL 
Michele Barden 
U.S. Environmental Protection Agency - 
Region 1 
5 Post Office Square, Suite 100 (06-1) 
Boston, MA 02109-3912 
barden.michele@epa.gov 
Claire Golden 
Surface Water Discharge Program 
Massachusetts Department of Environmental 
Protection 
150 Presidential Way 
Woburn, MA 01801 
claire.golden@mass.gov 
massdep.npdes@mass.gov 
RE: Boston Water and Sewer Commission Public Comments on
Draft NPDES Permit No. MA0103284 for the Massachusetts Water Resources
Authority Deer Island Treatment Plant 
Dear Ms. Barden and Ms. Golden: 
The Boston Water and Sewer Commission ("BWSC" or "Commission") appreciates the
opportunity to submit its public comments on the draft National Pollutant Discharge Elimination
System ("NPDES") Permit No. MA01030284 ("Draft Permit") for the Massachusetts Water
Resources Authority ("MWRA") Deer Island Treatment Plant ("DITP") that was issued for public
comment on March 31, 2023, by the U.S. Environmental Protection Agency ("EPA" or "Region
1" or "Region"). The Commission also submits these comments for and in response to the 2023
Draft Massachusetts Permit to Discharge Pollutants to Surface Waters for the MWRA DITP
("Mass. Permit") that was issued for public comment by the Massachusetts Department of
Environmental Protection ("MassDEP") on March 31, 2023. For the purposes of this letter, all of
the Commission's public comments herein are directed to both the Draft Permit issued by EPA
Region 1 and the Mass. Permit unless otherwise specified. 
The Commission is listed as a CSO-responsible Permittee and Co-Permittee in the Draft
Permit and Fact Sheet, and this Draft Permit would supersede the Commission's existing NPDES
Permit No. MA0l0l 192, issued on March 28, 2003. and modified on April 10, 2007. The
Commission appreciates EPA and MassDEP granting extensions to the public comment period
until November 28, 2023. The Commission submits these comments individually; however, it
supports the comments submitted by both the MWRA and the MWRA Advisory Board.

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page2 
The Commission has substantial concerns regarding the legal and technical basis for
issuance of the joint permit and the terms, conditions and obligations imposed by the Draft Permit
and Mass. Permit. Insofar as the Mass. Permit incorporates by reference provisions of the Draft
Permit, the Commission's public comments address both the Draft Permit and the Mass. Permit.
The Commission's public comments address the Draft Permit on both legal and technical terms.
The Commission engaged the services of Hazen and Sawyer to provide technical analysis and
review of the Draft Permit, those comments are incorporated below. 
1) The Integration of Co-Permittees into the Draft Permit is Without Basis and Exceeds
EPA's Authority. 
Attachment A to the Draft Permit identifies the Commission as a CSO-responsible Co
Permittee, responsible for Part LB (Combined Sewer Overflows), Part LC (Unauthorized
Discharges), Part LD (Notice of Elimination), Part LE (Operation and Maintenance), Part LF
(Alternate Power Source) and Part LJ (Reporting Requirements). Attachment B to the Draft Permit
identifies the Commission as a Co-Permittee for the "operation and maintenance of the sewer
systems" with respect to Part II Standard Conditions, Part I.C (Unauthorized Discharges), Part LE
(Operation and Maintenance), Part I.F (Alternate Power Source) and Part LJ (Reporting
Requirements). 
Prior to issuance ofthe Draft Permit, the Commission maintained a separate NPDES Permit
No. MA0lOl 192, which is now consolidated with the Draft Permit. The Commission objects to its
inclusion as a Co-Permittee in the Draft Permit, and objects to the consolidation of the
Commission's existing NPDES Permit No. MA0l0l 192 (as modified on April 10, 2007) into the
Draft Permit as a CSO-responsible Co-Permittee. The Commission did not submit a permit
application to be included in the consolidated Draft Permit, nor waive its right to do so. EPA's
justification for including the Commission as a Co-Permittee is not supported by its own policy. 
EPA regulations require applicants to "submit a complete application" in accordance with
40 CFR §§ 122.21 and 124.40. 1 EPA then "shall not issue a permit before receiving a complete
application for a permit." 2 The Commission has not submitted an application or requested
inclusion with the MWRA Draft Permit, yet EPA has included the Commission as a CSO Co
Permittee and Co-Permittee. In doing so, EPA has exceeded its authority. 
To support its actions, EPA cites Appendix D to the Fact Sheet (the "Permitting
Approach"), which describes the general policy of EPA Region 1 "to include and regulate the 
1 40 CFR § 122.21(a)(l). 
2 40 CFR § 122.21(e)(l). 
2

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page3 
owners/operators of the municipal satellite collection systems through a co-permitting structure"
and specifies that Region l's decision in any specific case will depend on the "specific facts when
permits are issued." The Permitting Approach states that regionally integrated publicly owned
treatment works ("POTW") often have ownership and operation structures that are divided among
multiple parties, which results in situations were "the owner/operator of the treatment plan many
times lacks the means to implement comprehensive, system-wide operation and maintenance
("O&M") procedures." 
Appendix D to the Fact Sheet presents Region's arguments for inclusion of the
Commission and forty-two (42) other Co-Permittees as "satellite sewer collection systems,"
despite no direct discharge to the waters of the United States from the separate sanitary systems
other than through the MWRA. The Region, while attaching no Co-Permittee specific system
performance or analysis of infiltration and inflow ("I/1"), simply asserts that it must include the
Co-Permittees to be consistent with its 2001 Interim I/I Policy designed to ensure sufficient control
ofinfiltration and inflow to prevent violations ofpermittees effluent limitations or overflows. 3 The
legal analysis and Permitting Approach ignore the definition of "Discharge or Discharge of
Pollutants" found in 314 CMR 12.02 which includes, ''discharges through pipes, sewers, or other
conveyances owned by a state, municipality, or other person which do not lead to a POTW...". 4 
The Region's legal analysis also ignores the definition of a "Discharge of Pollutant" found in 40 
C.F.R. 122.2 which specifically excludes discharges through pipes, sewers or other conveyances
owed by a State, municipality or other person which lead to a treatment works. 5 The Commission's
separate sanitary system and combined sanitary sewer system (unless during conditions of a CSO
activation) convey flows to the DITP owned and operated by the MWRA; they do not discharge
to surface waters. 
3 See Fact Sheet, Appendix D at 8. 
4 The full definition of "Discharge or Discharge of Pollutants" found in 314 CMR 12.02 reads: "any addition of any
pollutant or combination of pollutants to waters of the Commonwealth from any source, including but not limited to,
discharges from surface runoff which is collected or channeled by man, discharges through pipes, sewers, or other
conveyances owned by a state, municipality, or other person which do not lead to a POTW, and discharges through
pipes, sewers, or other conveyances, leading into privately owned treatment works. This terms does not include any
addition of pollutants by any indirect discharger." 
5 The full definition of"Discharge of a pollutant" found in 40 CFR 122.2 reads: "(a) Any addition of any "pollutant"
or combination of pollutants to "waters of the United States" from any "point source," or (b) Any addition of any
pollutant or combination of pollutants to the waters of the "contiguous zone" or the ocean from any point source'
other than a vessel or other floating craft which is being used as a means of transportation. This definition includes
additions of pollutants into waters of the United States from: surface runoff which is collected or channeled by man;
discharges through pipes, sewers, or other conveyances owned by a State, municipality, or other person which do
not lead to a treatment works; and discharges through pipes, sewers, or other conveyances, leading into privately
owned treatment works. This term does not include an addition of pollutants by any "indirect discharger."
( emphasis added) 
3

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page4 
The Region also erroneously treats systems owned and operated by separate municipalities
as a single POTW which is contrary to its own regulations. The Region, through the NPDES
permit, must treat each municipal system as its own, distinct system. The regulations define a
POTW to be "a treatment works ... which is owned by a State or municipality ... " is expressed
only in the singular. 6 40 C.F.R. § 403.3(q) (emphasis added). Similarly, the definition uses only
the singular to refer to "the municipality ... which has jurisdiction over Indirect Discharges to and
discharges from such a treatment works. " 7 The Region lacks the jurisdiction to issue the Draft
Permit and apply the Permitting Approach to the MWRA DITP, Commission, and 42 other
member communities through a plain reading of its own regulations. 
The Region also describes, "While relying on this cooperative approach, however, EPA
Region 1 also asserted that it had the authority to require that POTW collection systems be included
as NPDES permittees and that it would do so if it proved necessary." 8 Here, the Region attaches
site-specific analysis in Exhibit B to the Permitting Approach (Analysis of Extraneous Flow
Trends for Representative Systems) for the South Essex Sewer District ("SESD") and Charles
River Pollution Control District ("CRPCD") as "representative systems" for the MWRA. Exhibit
B was provided in defense of the Region's decision to seek "satellite sewer collection system"
status for the four systems connecting to the CRPCD system in light of criticism by the
Environmental Appeals Board ("EAB") in In re Upper Blackstone Water Pollution Abatement
District,9 that its decision was not justified. 
Neither the Draft Permit nor the Fact Sheet present any site- or system-specific analysis,
data, or proof that inclusion of the Commission and other Co-Permittees is "proved necessary."
The Region states that the Permitting Approach is necessary due to the representative systems
exhibiting evidence of 1/1 causing exceedances in the system, which the EAB found sufficient in 
In re Charles River Pollution District. 10 However, the Region infers that these two smaller
systems, consisting of six (6) communities (SESD) and four (4) communities (CRPCD) are
representative of the MWRA's system with forty-three (43) member communities.11 The Region
provides no analysis of the effectiveness of existing Massachusetts regulations upon the member
communities to reduce 1/1 from their respective systems or data supporting actual reductions by
the Commission and these communities 
6 See 40 C.F.R. §403.3(q). 
7 See Id. 
8 See Fact Sheet, Appendix D, at 8. 
9 14 E.A.D. 577 (EAB 2010). 
10 16 E.A.D. 623 (EAB 2015) 
11 Fact Sheet, Appendix D, Exhibit B cites data from the South Essex Sewer District, which includes the
communities of Beverly, Danvers, Marblehead, Middlebury, Peabody, and Salem, Massachusetts, and the Charles
River Pollution Control District, which includes the communities of Bellingham, Franklin, Medway, and Millis. No
data is provided from communities that are included as CSO Co-Permittees or Co-Permittees under the Draft Permit. 
4

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 5 
In the present case with the Draft Permit, the POTW is regionally integrated and the overall
system is divided among multiple parties, however there is no lack of comprehensive system-wide
O&M procedures. The DITP is owned and operated by the MWRA. While t~e MWRA is a distinct,
separate entity, it provides sewer services to member communities including the Commission and
forty-two (42) other communities 12 , collectively serving 3.1 million people in the Commonwealth
ofMassachusetts. The MWRA has robust O&M procedures in place, which includes the regulation
of wastewater discharge from member communities into the MWRA system through the issuance
ofpermits. For example, the Commission is currently operating under the 2023 MWRA Municipal
Discharge Permit, which regulates all discharges, septage disposal sites and direct connections to
the MWRA's sewerage system. This comprehensive permit, effective for calendar year 2023,
includes CSO management and reporting requirements and sampling and reporting requiremen~s.
The Commission, like other member communities, must apply for the Municipal Discharge Permit
to the MWRA annually and the Commission expects to receive an updated permit for calendar
year 2024. 
The Municipal Discharge Permit reqmres the elimination of excessive I/I. 13 The
Commission enforces the MassDEP requirements for I/I reduction plans requiring 4-to-1
reductions for all new developments and redevelopments with sewer connections exceeding
15,000 gallons per day of sewage. The inclusion of the Commission as a Co-Permittee for I/I is
redundant to the MWRA Municipal Discharge Permit, Massachusetts regulations and policy ofthe
Commission, and has not "proved necessary." 
The Permitting Approach is also inapplicable in the present case because the central
problem it is addressing does not exist in the Boston area. The MWRA, and the Commission as a
member community, actively implement O&M procedures to address important issues such as I/1.
In fact, the MWRA has been commended on its "impressive" progress reducing the volume of
CSO discharges into Boston Harbor and its tributary rivers and addressing underperforming
outfalls, most recently by the U.S. District Court of the District ofMassachusetts. 14 In the May 11,
2023 Schedule Seven Compliance Order Number 252, Judge Steams highlighted that the MWRA
has reduced CSO discharges to levels below what is required by its CSO Long-Term Control Plan, 
12 The MWRA also provides water distribution or supply only to a number of communities. 
13 Condition 10 of the 2023 MWRA Municipal Discharge Permit states: "The Commission, in cooperation with the
MWRA, shall eliminate excessive infiltration and inflow (1/1) that is tributary to the MWRA sewer system. The
determination of I/I that is considered "excessive" shall be in accordance with the standards contained in:
Massachusetts Department of Environmental Protection - Guidelines Massachusetts Department of Environmental
Protection - Guidelines for Performing Infiltration/Inflow Analyses and Sewer System Evaluation Surveys, revised
May 2017, or as may be revised by MassDEP." 
14 Case 1:85-cv-00489-RGS, Document 1908, 05/11/23. 
5

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page6 
and has made "significant progress" to address technical and engineering issues in 
underperforming outfalls. 15 Additionally, Judge Steams "laud[ed] the commendable efforts that
the MWRA has made over the past year ... to meet with, inform, and elicit the views of
stakeholders, community leaders, and environmental associations." 16 
The Commission has made substantial progress in reducing infiltration and inflow (I&I)
over the past several years, in part due to the requirements contained in existing Massachusetts
regulations 17 and the Commission's current MWRA Municipal Discharge Permit. The
Commission's 2023 MWRA Annual 1/1 Questionnaire is attached hereto as Appendix A, which
includes a listing of each sewer system rehabilitation project conducted by the Commission in the
MWRA's Northern System (since 1987) and Southern System (since 1988) 18 . The three-year
average wastewater flow from the Commission to the MWRA for 1994 to 1996 was 107.21 million
gallons per day (MGD) 19 , of which 54.59 MGD was I/I or 51 percent of the flow. The three-year
average wastewater flow from the Commission to the MWRA for 2019 to 2022 was 84.14 MGD,
of which 27.16 MGD was 1/1 or 32.3 percent of the flow. This represents a 50.2 percent reduction
in the I/I flow from the Commission to the MWRA. 
The Commission and MWRA continue to implement I/I reduction projects. In May 2017,
the Commission completed a Citywide Inflow and Infiltration Analysis. That project
recommended twelve (12) Sewer System Evaluation Survey ("SSES") projects for the
Commission to implement. The Commission completed five SSES's, a contract for one SSES is
being finalized, and RFP's were requested for a SSES that has combined two of the recommended
areas. In addition to the MWRA's LTCP, the Commission has been separating 270 combined
sewer acres in Roxbury tributary to Nubian Square. This separation project began in 2016, and
the Commission expects to complete the project in 2025. A project to separate 235 acres of
combined sewers in South Boston began in July 2021 utilizing five construction contracts with all
separation work expected to be completed by November 2027. The Commission will also be
separating 230 acres in East Boston under five contracts. Construction is expected to begin in
2024 and the entire project will be completed by 2031, resulting in a completely separate sewer
system serving East Boston. 
Part 10 of the Commission's MWRA Municipal Discharge Permit requires the
Commission to "eliminate excessive infiltration and inflow (1/1) that is tributary to the MWRA
sewer system." EPA has not provided evidence that the Commission's work is insufficient or
inadequate in addressing and reducing I/I. The MWRA does not "lack the means to implement 
15 Case 1:85-cv-00489-RGS, Document 1908, 05/11/23, page 2. 
16 Case 1:85-cv-00489-RGS, Document 1908, 05/11/23, page 5. 
17 See 314 CMR 12.04(2). 
18 See BWSC MWRA Annual 1/1 Questionnaire 2023, including Attachment B (Northern System) and Attachment
A (Southern System). 
19 Included at the end of Appendix A. 
6

Michelle Barden, U.S. EPA - Region 1 
Claire Golden, Surface Water Discharge Program, MassDEP ~ November 28, 2023 
~ Page 7 
comprehensive, system-wide operation and maintenance ("O&M") procedures," the opposite is
true. The Permitting Approach is inapplicable to the MWRA and by extension the Commission,
and thus it is inappropriate to include the Commission as a Co-Permittee and CSO-responsible Co
Permittee. 
The Draft Permit Fact Sheet, as evidence of excessive 1/1, mentions the 4,000 sanitary
sewer overflows ("SSOs") that occurred in the MWRA system during a 14-year period, with the
Commission accounting for roughly 50% of those reports as evidence of excess 1/1. 20 Importantly
however, EPA fails to mention that since 2012, the Commission has instituted mandatory SSO
notification within twenty-four (24) hours for SSOs from the sanitary sewer system in connection
to the operation and maintenance ofits sewer system and the separate stormwater system governed
by a Consent Decree executed with EPA in September 2012 and its separate NPDES Permit issued
in 1999. 21 The SSOs reported under the Consent Decree for this period largely include blockages
in the separate sanitary sewer (fats, oils, grease, debris), broken pipes, or even private building
backups exceeding 50 gallons (not caused by the Commission's system), all of which may be
unrelated to 1/1 and capacity issues in the separate sanitary sewer system. The Region uses the
volume of SSO reports during the 14-year period as a straw man argument justifying the Permitting
Approach as evidence ofexcess 1/1. Given that the reported SSOs during that period include SSOs
resulting from a variety of causes other than 1/1, EPA's reliance upon this in the Fact Sheet is
misplaced. 
Finally, the concern expressed by Region 1 with 1/1 to justify the Permitting Approach for
the Co-Permittees is in opposition to the Draft Permit's reduction in the Rolling Average Effluent
Flow. Draft PermitPartl.A.1 limits the flow for the DITP from 436 MGD to 361 MGD, a reduction
of 75 MGD. There is no facility-specific information or other evidence specific to the MWRA,
Commission or other Co-Permittees presented in Appendix Dor the Fact Sheet that proves the
Permitting Approach as necessary or justified. 
2) The Draft Permit's General Narrative Prohibition is Contrary to the Clean Water Act
and EPA Regulations. 
Part I.B.2(a) of the Draft Permit includes the generic narrative prohibition that the MWRA
and Co-Permittees may not "cause or contribute to" violations of water quality standards. Such
language is inconsistent with the Clean Water Act, EPA regulations, and federal case law. As
such, the Commission objects to its inclusion. 
20 Draft Permit Fact Sheet at 99. 
21 Boston Water and Sewer Commission, Municipal Separate Storm Sewer System NPDES Permit No.
MAS0IO00I, September 29, 1999. 
7

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 8 
EPA's regulations require that NPDES permits must specifically control all pollutants or
pollutant parameters (either conventional, non-conventional, or toxic pollutants) which the
Director determines are or may be discharged at a level which will cause, have the reasonable
potential to cause, or contribute to an excursion above any State water quality standard, including
State narrative criteria for water quality." 22 EPA is obligated to determine if a discharge causes or
has the reasonable potential to cause or contribute to an excursion above any water quality standard
("WQS"). 23 EPA must consider the following factors to determine if a pollutant or discharge has
a reasonable potential to cause or contribute to a violation ofWQS: 
1) "existing controls on point and nonpoint sources of pollution;" 
2) "the variability of the pollutant or pollutant parameter in the effluent;" 
3) "the sensitivity of the species to toxicity testing (when evaluating whole effluent
toxicity);" and 
4) "where appropriate, the dilution of the effluent by the receiving water." 24 
Federal case law requires clear standards from EPA, and specifically prohibits this general
narrative language. In International Paper Co. V. Ouelette, the Supreme Court confirmed that
Congress intended for there to be "clear and identifiable" standards for water discharges, rather
than "vague" and "indeterminate" standards, such as state nuisance standards. 25 IfEPA determines
that the discharge of a pollutant will cause, has the reasonable potential to cause, or contribute to
a violation of WQS, the permit must contain water quality based effluent limitations - specific
pollutant limitations or management practices - that control that pollutant. 26 In NRDC, the Second
Circuit determined that EPA's use of language in a Vessel General Permit that imposed a general
duty to meet applicable WQS (similar to the generic language in the Draft Permit) failed to provide
the permittee with "guidance as to what is expected or to allow any permitting authority to 
determine whether [a permittee] is violating water quality standards". 27 This lack of guidance led
to the court concluding the general prohibit failed to ensure compliance with the CWA. 28 Here
the Commission, MWRA and other communities lack the guidance or set enforceable limits
needed to ensure compliance with the CWA and protection of WQS. 
The Mass. Permit similarly fails to comply with its regulations requiring site and discharger
specific permit requirements to provide specific limits to assure attainment and maintenance to 
22 40 CFR § 122.44(d){l)(i). 
23 See 40 CFR § 122.44(d){l)(ii).
24 Id. 
25 479 U.S. 481,496 (1987). 
26 See Id.; see also, Natural Res. Def Council, Inc. v. EPA, 808 F.3d 556 (2d. Cir. 2015). 
27 See Natural Res. Def Council, Inc. v. EPA, 808 F.3d at 578. 
28 See Id. at 580. 
8

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 9 
protect WQS. 29 The inclusion of the generic prohibitions does not comply with the requirements
of 314 CMR 3.11(3) by avoiding the reasonable potential analysis and discharger specific
limitations designed to provide the permittees with enforceable limits to protect water quality. 
For the reasons cited above, the Region and MassDEP should remove the generic, overly
broad language from Part I.B.2(a) of the Draft Permit. 
3) The Draft Permit's General Narrative Prohibition is an Impermissible Delegation of its
Authority Under the Clean Water Act and Subjects the Commission to Unnecessary 
Post-Hoc Enforcement. 
The CWA provides a "permit shield" that deems NPDES Permittees to be in compliance
with the CWA so long as they comply with the specific terms oftheirpermits. 30 This permit shield
is eliminated by using generic prohibitions, because any discharge of a pollutant that adds or
contributes to an existing water in excess of water quality standards results in a violation of this
broad, generic permit term. 
These generic prohibitions avoid the necessary step of evaluating whether a particular
pollutant has a reasonable potential to cause or contribute to a WQS violation. Instead, EPA (or
its delegated authority) can assert that the discharge of a pollutant, or any act or omission to cause
or fail to prevent that discharge by a permitted agency, is a violation of the CWA simply because
the receiving water is in violation of WQS. This results in no clear guidance or notice as to how
the Commission or other permittees must take action to protect water quality and ensure
compliance with the CWA. 
Clear limitations provide NPDES permittees such as the MWRA, Commission and
member communities with ascertainable standards to which they may design their systems and
control their discharges. By including general narrative prohibitions, EPA delegates its
rulemaking authority to third parties, by leaving the door open for post-hoc enforcement. The
Commission has first-hand experience with such third-party suits, which seek to impose
obligations upon NPDES permittees beyond those placed by EPA after its extensive rulemaking
process. Such suits reopen matters that should have been settled in EPA NPDES permit
proceedings, and the costs of defending these suits are ultimately borne by the ratepayers. 
In 2010, the Conservation Law Foundation filed a citizen suit alleging, among other things,
that discharges from the Commission's MS4 Permit violated "the prohibition against causing or 
29 See 314 CMR 3.11(3). 
30 See 33 U.S.C. § 1342(k); see also, EPA v. California, 426 U.S. 200 (1976). 
9

Michelle Barden, U.S. EPA-Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 10 
contributing to the violation of water quality standards" in its NPDES permit. 31 As a result of this
suit, the Commission entered into a Consent Decree which effectively modified its existing
NPDES permit issued in September 1999. By way of a citizen action suit, the Conservation Law
Foundation and EPA were able to circumvent the traditional permit issuance process. 
The Consent Decree included a number of short-term and long-term operational,
management, and maintenance programs, such as an expanded sanitary sewer overflow
notification requirement not found in the original permit, as well as the requirement to develop
and implement a Best Management Practice Recommendations Report. The estimate to implement
the 30-year plan for green infrastructure, low-impact development and best management practices,
as approved on October 16, 2016 was Six Hundred Fifty-Two Million Dollars ($652,000,000) for
full life-cycle costs. As a result, the Commission's 2023-2025 Capital Improvement Plan includes
$8,485,000 in maintenance obligations for the Consent Decree and $44,569,807 for stormwater,
green infrastructure, and Low Impact Development (LID) projects. In response to these existing
regulatory compliance obligations, the Commission is proposing to fund these obligations through
the implementation of a new stormwater charge imposed on its ratepayers. This 30-year cost of
the BMP Implementation Report, the resulting stormwater charges, and the other ongoing
management, maintenance, and upgrade costs since 2012 are the true costs of post-hoc 
enforcement of the CWA. 
Therefore, EPA and MassDEP should strike the broad "cause or contribute" language from
Part I.B.2(a) to limit the liability ofthe Commission, as well as the MWRA, CSO Responsible Co
Permittees and Co-Permittees under the Draft Permit from unnecessary post hoc enforcement of
this impermissible language. 
4) Use of the Exhibit B to the Second Stipulation as Attachment I for the Authorized
Typical Year Discharge Activation and Volumes for Treatment and Abatement of CSOs
is Inappropriate. 
The Commission objects to the Draft Permit's incorporation of Exhibit B of the Second
Stipulation ("Exhibit B") from the Boston Harbor Litigation 32 as Attachment I as technology-based
effluent limitations ("TBELs") for the Draft Permit as inappropriate, inconsistent with the CSO
Control Policy and EPA Guidance. The use of Exhibit B would place the MWRA, Commission
and other CSO-Responsible Co-Permittees at risk of enforcement action or a civil suit upon 
31 Complaint, Conservation Law Foundation, Inc. and United States ofAmerica v. Boston Water and Sewer
Commission, et al., Civil Action No. 10-cv-10250-RGS, Document 9 (September 28, 2012)(D. Mass. 2012). 
32 US District Court of Massachusetts, 2006, Second Stipulation of the United States of America and the
Massachusetts Water Resources Authority on Responsibility and Legal Liability for Combined Sewer Overflows 
Control, www.mwra.com/cso/2006/0306.memo. ndf, Fact Sheet at 106, FN 285. 
10

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 11 
issuance of the Draft Pennit. Exhibit Bis from a 2006 Court order that does not reflect or account
for extensive LTCP work completed to date by the MWRA, Commission, as well as other CSO
Responsible Co-Permittees. Given that Exhibit B was issued more than 15 years ago, does not
account for the work completed to date and was not intended as an inflexible limit, utilizing Exhibit
Bas TBELs would be inconsistent with EPA's own guidance and regulations that require TBELs
to incorporate all reasonably available and relevant data. 33 Given the ongoing, active litigation
before the Court, ongoing compliance work, and compliance schedules, EPA' s use of Exhibit B
as de factor TBELs would frustrate the purpose of Exhibit B as a compliance goal rather than a
limit in a NPDES permit. Therefore, it is inappropriate for EPA to incorporate Exhibit B in
Attachment I in the Draft Permit and the Commission requests that it be removed. 
In further support its position, the Commission supports and incorporates comments,
objections, and alternates proposed by the MWRA in its public comments 34 regarding the inclusion
of Exhibit B in Attachment I of the Draft Permit. 
5) The Major Storm and Flood Events Planning Provisions are Overly Burdensome and
Not Currently Feasible. 
The Major Storm and Flood Event Planning provisions of the Draft Permit place overly
burdensome requirements on the Commission, the MWRA, CSO Responsible Co-Permittees and
Co-Permittees. The Major Storm and Flood Event Planning Provisions and Sewer System O&M
Plan also impose timelines for implementation that are not feasible given the Commission's current
staffing and resources, as well as the public bidding requirements should the Commission need to
engage appropriately qualified professional consultants to ensure compliance with these proposed
obligations. 
Permit Part I.E.2(e)(l) requires the Commission to, within six (6) months of the Draft
Permit's effective date, develop a Sewer System O&M Plan in accordance with Draft Permit Part
I.E.2(e)(3), and submit a "schedule for the development and implementation of' said Sewer
System O&M plan. The Sewer System O&M Plan must then be fully implemented within two (2)
years of the Permit's effective date. See Draft Permit Part I.E.2(e)(3). As part of the Sewer System
O&M Plan, the Commission is also required under Draft Permit Part I.E.2(e)(2) to develop and
implement a Sewer System Flood Events Plan within one (1) year of the Draft Permit's effective 
33 NPDES Permit Writers' Manual, Exhibit A-2 Glossary. 
34 The Commission supports the MWRA's comments on alternative approaches to modify Exhibit B to reflect the
technology based limits actually achieved for the 19 CSO Outfalls with exceptions in Table I and on Pages 30 and
31 of the Authorities comments, specifically to reflect the Q4 2022 model prediction plus nominal increases for
MWR203 and BOSO 17 due to ongoing and planned work under the Harbor Litigation case in both Somerville and
Boston that may result in temporary increases in volumes. The Commission expects planned work to offset a
portion, if not all, of the increases at BOSO17 once the upstream work is completed. 
11

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 12 
date. These planning and reporting prov1s1ons would place additional burdens on the
Commission's resources, and are not supported by sufficient data to justify their imposition. 
The Commission is already obligated to operate its sewer system in accordance with
Massachusetts regulations 35 , and EPA has not provided evidence that such regulations are not
adequately providing for proper operations and maintenance of the Commission's sewer systems. 
The Region relies again on the broad authority to regulate the impacts of climate adaptation
under the guise of "operation and maintenance" requirements of the CWA, specifically CWA §
l0l(a), 40 C.F.R. §§ 122.41(d), (e), (n). These provisions are designed to ensure compliance with
operational functions to avoid upsets and encourage preventative measures to prevent unlawful 
discharges to navigable waters or the environment. These provisions are not designed to justify
long-term planning and implementation well beyond the stated term ofthe Draft Permit and do not
directly regulate discharges. This is especially true given the proposed 80-to-100-year outlook
required by these provisions when the term of the NPDES permits is limited to a five-year term. 36 
These provisions impose unreasonable timeframes for compliance, unclear guidance on what data
the Commission and communities must rely upon and re-evaluate their practices, ongoing
reporting requirements, and what steps are required to implement the planned long-term mitigation
measures. 
The Commission believes the imposition of these new Major Storm and Flood Events Plan
and Sewer System O&M plan for climate adaptation is not justified nor authorized by the CWA,
and the provisions should be removed from the Draft Permit. The Commission also believes that
its position that these provisions are impractical, poorly defined, overly burdensome and impose
unrealistic timeframes for compliance is justified the Region's recent decision to extend timelines
and substantially revise the similar provisions in response to comments to the Northampton
Wastewater Treatment Plan, NPDES Permit No. MA0101818 issued on September 28, 2023. 37 
The draft NPDES Permit No. MA0101818 also included the novel Major Storms and Flood Events
Plan (since renamed the Adaptation Plan) .. 38 
Finally, the Commission believes Region 1 failed to provide a cost-benefit analysis to study
impacts of imposition of the Major Storm Events Planning and related Sewer System O&M
provisions upon the MWRA, Commission and member communities. The Commission should be
afforded the opportunity to evaluate the costs to implement these requirements and better inform
its rate-payers of the consequences of these obligations. The Commission does support taking 
35 314 CMR 12.00. 
36 33 U.S.C. §§ 1342(a)(3), (b)(I)(B); 40 C.F.R. § 122.46(a); see also 314 CMR 3.11(8). 
37 https://www3.epa. iwv/regionl/npdes/permits/2023/finalma0101818 permit. pdf 
38 See Response to Northampton Comments, 14. 
12

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 13 
action to prepare for the impacts of climate adaptation; however, the Draft Permit is not the
appropriate forum for these mandates. 
6) The Liability and Obligations of Co-Permittees and CSO Responsible Co-Permittees
are Not Clearly Defined in the Draft Permit. 
Even if EPA and MassDEP could lawfully structure the Draft Permit for the DITP to
include the Commission and 42 other member communities, neither the Draft Permit nor the Mass.
Permit define the obligations of the co-permittee parties with sufficient clarity to ensure that they
are not held liable for conduct or events over which they have no control. The Region also provides
no explanation or justification for declaring the Commission and three other CSO Responsible Co
permittees as severally liable only for their own activities and municipally owned sewer systems
in the Draft Permit preamble, Part LB, Part LC, Part I.D, Part I.E, Part LF., Part LF and all of Part 
II. The Region provides no guidance or definition of how the Commission and three (3) other
CSO communities will be liable for a failure of the collective Nine Minimum Controls, to which
each community works in concert with the MWRA. 
The Draft Permit should provide clear guidance as to the obligations of each CSO
Responsible Co-Permittee with respect to these obligations to which the MWRA has the same
requirements. The issue of liability also raises concerns by the Commission because this permit
will likely still be in effect after the conclusion or completion of the LTCP when the MWRA may
step back from certain obligations for combined sewer overflows that it currently maintains. 
The Region must revise the Draft Permit, Part I.B, and Part I.E.2 to provide the
Commission, member communities and MWRA with absolute clarity that the Co-Permittees are
not responsible for MWRA's noncompliance and vice versa. A better approach would be to
remove the purported Permitting Approach; to consolidate all the outstanding permits into the
Draft Permit reaches beyond the Region's permitting authority. The Mass. Permit similarly fails
to include any justification to this consolidation and approach. The Draft Permit language in Part
LC, Part I.D, and Part LE must also be clarified further to remove any ambiguity regarding the
several liability ofMWRA, the CSO-responsible Co-permittees, and the Co-permittees. 
It is critical that EPA and MassDEP clearly delineate these responsibilities to avoid
disrupting the longstanding relationship between MWRA and its member communities, and that
the Draft Permit avoid unnecessary liability and risks among the communities themselves for
potential non-compliance. It is also important that EPA and MassDEP revise the Draft Permit to
avoid establishing the MWRA as a regional enforcement agency to which both EPA and
MassDEP appear to delegate their statutory obligations. 
7) The Timeframe for Analyzing and Updating Local Limits in Part I.G.7.(b) are Not
Feasible. 
13

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 14 
The Draft Permit Part I.G. 7(b)(2) requires the MWRA to submit a technical written
evaluation to EPA analyzing the need to revise local limits within ninety (90) days of the effective
date of the Draft Permit. Should that evaluation determine local limits need to be revised, then the
MWRA must update the local limits within 120 days ofnotification by EPA. The MWRA, through
its Municipal Discharge Permit, also regulates the industrial discharges to its system (consistent
with the provisions in Part I.G.5) from the Commission and forty-two (42) other member
communities. To require the MWRA to analyze the local limits for its system, the Commission's
system and systems of forty-two ( 42) other member communities within ninety (90) days is not
feasible. Furthermore, by virtue of the Municipal Discharge Permit and legal authority and
delegated enforcement in Part I.G.5, this requirement will be passed through to the member
communities including the Commission. 
The Commission requests that Region 1 provide a minimum of 180 days for the MWRA
to analyze the local limits and allow time for the MWRA to coordinate with the Commission and
other member communities to provide an effective and complete evaluation oflocal limits. 
8) EPA Should Provide an Exemption to the Requirements of Part I.G.S(e) Given the
Pending Listing of Certain PFAS Analytes as Hazardous Substances. 
On September 6, 2022, EPA published rulemaking to list Perflourooctanoic Acid (PFOA)
and Perflourooctanesulfonic Acid (PFOS) as hazardous substances under both Comprehensive
Environmental Response, Compensation and Liability Act (CERCLA) and Resource Conservation 
and Recovery Act (RCRA). 39 EPA intends to issue a final rule designating these two (and likely
more) PFAS analytes as hazardous materials by February 2024, which will be within the effective
term of the Draft Permit once final. The Commission believes EPA should provide an exemption
to the requirements of Part l.G.8( e) with respect to the notification of all Industrial Discharges of
"any discharge into the POTW of a substance, which, if otherwise disposed of, would be a
hazardous waste under 40 CFR Part 261" given the pending listing of certain PFAS analytes under
CERCLA and RCRA. 
The Draft Permit at Part I.G.4 has the MWRA (and by virtue of the Municipal Discharge
Permits, the Commission and member communities) conducting annual sampling often industries
and "any other known or expected sources of PFAS." This broad sampling program, which must
be done within one (1) year of the effective date of the permit, will likely include potential sources
of PFOA and PFOS. The Commission recognizes that discrete industrial dischargers and sources
of these two analytes may be identified through sampling and notified; however, all sources of 
39 See 87 FR 54415, September 6, 2022, Docket No. EPA-HQ-OLEM-2019-0341; FRL-7204-02-OLEM, the final
rule is anticipated by February 2024. 
14

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023 
Page 15 
upstream contributions of these analytes may be difficult if not impossible to determine for the
MWRA, Commission and member communities. 
Therefore, the Commission requests that EPA grant an exemption from Part I.G.8(e) for
any PFAS analytes listed under either CERCLA or RCRA, to the extent those sources are not
discretely identified through the industrial effluent sampling performed by the Significant
Industrial Users (SIUs). Given the broad sources of PFAS analytes in the waste stream,
acknowledged by the broad sampling provisions in Part I.G.4, these provisions have the potential
to be overly broad and unduly burdensome on the MWRA, Commission and all member
communities receiving industrial discharges. 
9) The Reduction of the Rolling Annual Average Effluent Flow Limit is Improper and
Unjustified. 
The Commission objects to the inclusion of the Rolling Annual Average Effluent Flow limit
of 361 MGD, set forth in Draft Permit Part I.A. I and Fact Sheet Section 2.3, because EPA cannot
regulate flow as a pollutant, the imposition of the limit is not justified by the Reasonable Potential
Analysis, and EPA has not established that 1/1 and continued proper operation and maintenance of
the DITP by MWRAjustifies the imposition of the reduced limit. 
In the Draft Permit, EPA proposes to replace the dry day rolling annual average effluent flow
limitation of 436 MGD with a rolling average effluent flow limitation of 361 MGD. In the Fact
Sheet at Section 2.3, EPA sets out the rationale for the general inclusion of an effluent limitation
on flow and replacing the previous flow limitation including: 
1. Discharge from the MWRA facility is a pollutant. 
2. A limitation on flow is necessary to assure that the results of the reasonable potential
analysis "remain sound" throughout the term of the permit. 
3. An effluent flow limit set at the design capacity will require MWRA to properly
operate and maintain the DITP by operating the wastewater treatment system within
the facility's design flow. An effluent flow limit is also necessary to minimize or
prevent infiltration and inflow (I/1), which could result in unauthorized discharge or
otherwise compromise proper operation and maintenance of the facility. 
(a) EPA's Analysis of Flow as a Pollutant is Not Authorized by the Clean Water Act
and is Unreasonable. 
In Part 2.3 of the Fact Sheet, EPA contends that "sewage treatment plant discharge" is a
pollutant based on the definition of pollutants in 33 U.S.C. § 1362(6) citing the mention of the
terms, "municipal", ''waste" and "sewage" discharged into waters. The full definition reads as
follows: 
15

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 16 
The term ''pollutant" means dredged spoil, solid waste, incinerator residue, sewage, 
garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive
materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial,
municipal, and agricultural waste discharged into water. This term does not mean (A)
"sewage from vessels or a discharge incidental to the normal operation ofa vessel ofthe
Armed Forces" within the meaning ofsection 1322 ofthis title; or (BJ water, gas, or other
material which is injected into a well to facilitate production ofoil or gas, or water derived
in association with oil or gas production and disposed ofin a well, ifthe well used either
to facilitate production or for disposal purposes is approved by authority of the State in
which the well is located, and ifsuch State determines that such injection or disposal will
not result in the degradation ofground or surface water resources. 
The terms POTW and POTW Treatment plant are defined at 40 CFR § 403 as follows: 
(q) The term Publicly Owned Treatment Works or POTW means a treatment works as
defined by section 212 ofthe Act, which is owned by a State or municipality (as defined by
section 502(4) of the Act). This definition includes any devices and systems used in the
storage, treatment, recycling and reclamation ofmunicipal sewage or industrial wastes of
a liquid nature. It also includes sewers, pipes and other conveyances only ifthey convey
wastewater to a POTW Treatment Plant. The term also means the municipality as defined
in section 502(4) ofthe Act, which has jurisdiction over the Indirect Discharges to and the
discharges from such a treatment works. 
(r) The term POTW Treatment Plant means that portion ofthe POTW which is designed to
provide treatment (including recycling and reclamation) of municipal sewage and
industrial waste. 
The facilities covered by Draft Permit meet the definition of a POTW, and the DITP
specifically meets the definition of a POTW Treatment Plant. The DITP is designed to treat
municipal wastewater to remove pollutants contained in the municipal sewage and industrial
waste. The reclaimed water discharged from DITP does not meet the definition of a pollutant set
out in 33 U.S.C. § 1362(6), therefore it is not subject to regulation as a pollutant. 
b) EPA Does Not Have a Regulatory Basis for the Imposition of the Effluent Flow
Limitation Based Upon the Justification of Ensuring Proper Operation and
Maintenance. 
The DITP has an average design flow of 361 MGD with a peak treatment capacity of 1.3
billion gallons per day. In the Fact Sheet, EPA cites the standard permit condition (Part II.B.1) to
properly operate and maintain the treatment facility and uses this requirement as a basis for
operating within the design flow. 40 EPA also intends for the effluent flow limitation to "mitigate"
any I/I related violations of the permit that could harm human health and the environment. 
4 °Fact Sheet, Section 3.1 at 20. 16

Michelle Barden, U.S. EPA - Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 17 
The DITP has demonstrated consistent proper operation and maintenance through
compliance with effluent limitations on BOD, TSS, fecal coliform and total residual chlorine. The
2018-2022 DMR summary shows that DITP was in full compliance with these effluent limitations. 
In addition to compliance with the effluent limitations for the above referenced parameters,
the DITP had no violations of the percent removal requirements for CBOD/NH3-N and TSS. In
fact, the median percent removal from 2018-2022 for both CBOD/NH3-N and TSS was
approximately 95%. The DITP's performance does not indicate that I/I has any impact on plant
performance. That said, each of MWRA's member communities are subject to the requirements
of360 CMR 10.00 which includes provisions that specifically address I/I including a requirement
that any new sanitary sewer be designed to minimize infiltration and inflow. 
EPA does not have a regulatory basis for the effluent flow limitation proposed in the Draft
Permit since discharge of flow is not a pollutant under the Clean Water Act and it is not necessary
to safeguard water quality standards and it is not necessary to ensure proper operation and
maintenance. The EPA proposes to implement an effluent limitation with significant cost impacts
to be shouldered by MWRA's member communities without any measurable water quality benefit
in the receiving waters. 
EPA should remove the reduced effluent flow limit or at a minimum replace the proposed
limit with the current 436 MGD because there is no regulatory basis and the imposition of the flow
limitation under the guise of proper operation and maintenance is also not supported. The
Commission also reincorporates its arguments set forth in Comment 1 above, demonstrating the
efforts to reduce I/I by member communities. Finally, EPA lack authority to regulate flow as a
pollutant and/or use flow as a surrogate for pollutants 41 . For these reasons, inclusion ofthe reduced
rolling annual average flow limit is both unreasonable and not based on law or facts. 
10) That Commission Shall Continue to Utilize Current Methods for Measurement of Some
or All CSOs 
The Draft Permit in Parts I.B.6 lists "continuous" sampling of flow within the monitoring
requirements section ofthe table in Part I.B.6. The Commission reiterates that the current approach
utilized by the Commission (including the MWRA and CSO Co-Permittees) for measurement of
discharges from the Commission's 28 CSOs listed in Appendix A, is consistent with and
authorized by Part I.B.3(g). 
Figure 1 depicts Commission outfalls listed within Appendix A of the Draft Permit. In the
figure, CSOs which are included in Appendix A but are not currently monitored are shown as
orange squares. The outfalls shown are all part of the North Dorchester Bay Storage Tunnel, a
completed CSO control project that has essentially eliminated CSO activations for all the
aforementioned outfalls except during catastrophic storms with a return period of greater than or 
41 See Virginia Department ofTransportation et al v. United States Environmental Protection Agency et al., case
number 1: l 2-cv-0077 5. 
17

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 18 
equal to twenty-five (25) years. While not currently monitored by the Commission, the MWRA
and Commission can estimate the CSO flows for these outfalls in the unlikely event of activation
during catastrophic storms. During storms with return periods of greater than or equal to five (5)
years, the North Dorchester Bay outfalls will activate, but will discharge only stormwater. Since
2011 , no CSO activations have occurred at these outfalls (BOS081, BOS082, BOS084, BOS085,
and BOS086), even during hurricanes, northeasters, and tropical storms. 
CSO-Outfalls 
f.tTl~'!'.. .t'°'
111<1\>~irQ,
F2nt:ca; ~'bac:11'.11 
iJ o..s 
C.W.03 
19'CSC082 
Figure 1 - BWSC Outfalls in Appendix A 
In 2022, the MassDEP granted MWRA's request to exempt these outfalls in North
Dorchester Bay (BOS081, BOS082, BOS084, BOS085, and BOS086) from their requirement to
post signage notifying the public about the location of CSOs, pursuant to 314 CMR 16.05(3), as
these CSOs are, for all reasonable intents and purposes, eliminated. MWRA, as the sole operator
of the South Boston CSO Storage Tunnel, agreed to provide public CSO activation notifications 
18

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 19 
in the unlikely event that the tunnel's capacity is overwhelmed and the tunnel overflows.
Therefore, the Commission should be exempted from the requirement to post signage, install
continuous flow monitors, and notify regulators, the public, and other stakeholders about CSO
activations at these five North Dorchester Bay outfalls. 
In light of the effectiveness of the CSO storage tunnel and 25-year level of control, the
continuous monitoring requirement should not apply to the North Dorchester Bay Outfalls
(BOS081, BOS082, BOS084, BOS085, and BOS086). The Commission requests that it be
permitted to utilize estimated flow methods and models, in coordination with the MWRA to predict
activations at those CSOs consistent with Part I.B.3(g). 
11) Additional Issues that Region 1 Needs to Revise in the Draft Permit: 
A. Draft Permit Cover Page, Part I.B.2 and Part I.B.3, specifically reference Attachment I
that includes five (5) Commission CSO outfalls that are closed and should be removed
from the permit. Specifically, the Commission requests that CSO outfalls BOS005,
BOS006, BOS007, BOS072, and BOS008 •be removed and no longer be subject to
regulation under the Draft Permit. 
B. Part LG. IO should be removed as redundant to the language and requirements set forth
in Part I.G.4 of the Draft Permit. 
The Commission appreciates the opportunity to comment on the Draft Permit. Please feel
free to contact the Commission's Chief Engineer, John P. Sullivan, Jr., or General Counsel Robert
LaMarca, if you have any questions or would like to discuss the resolution of any of the issues
raised above. Thank you again for your time and attention to this important matter. 
Sincerely, 
/rfao£ra 
Henry F. Vitale, CPA,
Executive Director, BWSC 
Cc: John P. Sullivan, P.E., Chief Engineer, BWSC
Robert M. LaMarca, Esq., General Counsel, BWSC
Charlie S. Jewell, Director of Planning & Sustainability
Sherilyn Burnett Young, Esq., Rath, Young and Pignatelli, P.C. 
19

Michelle Barden, U.S. EPA- Region 1
Claire Golden, Surface Water Discharge Program, MassDEP
November 28, 2023
Page 20 
James Steinkrauss, Esq., Rath, Young and Pignatelli, P .C.
Lauren Kilmister, Esq., Rath, Young and Pignatelli, P.C.
Saya Ann Hickey, P.E., ENV SP, Hazen and Sawyer 
20

Appendix A 
Draft Permit No. MA0103284 
BWSC Comments BOSTON WATER AND SEWER COMMISSION
NORTHERN SYSTEM 
MWRA ANNUAL
1/1
QUESTIONNAIRE 
(To be submitted to MWRA Community Support Program by July 28, 2023)
Community Support Contact: Jon Szarek, P.E. 
(617) 788-4358 or jon.szarek@mwra.com 
- NAME: 
__
_
____;;..
A =
d=a=m=----cH=o=r=st
=----=-
J= ul
::.,.y
_,6
'--'--,
=2
=
02=3
'-----
---------- --- 
- 
Name
of
Person Updating Questionnaire and Date 
1. 
Contact Person for
1/1
Issues: 
Charlie Jewell, Director
of
Planning John Sullivan, Chief Engineer
Boston Water and Sewer Commission Boston Water and Sewer Commission 
980 Harrison Avenue 980 Harrison Avenue
Boston, MA 02119 (617) 989-7444 Boston, MA 02119 (617) 989-7431 
2. General Information on Sewer System: 
- Miles
of
separate sanitary sewers: (Northern) 328 
- Miles
of
combined sewers: (Northern) 256 
•- Total miles
of
sewers (Total System): 854 
- Inch miles
of
sewer (Total System): 14,876 
- Number
of
service connections: (Northern) 63,912 
- Number
of
connections to MWRA System: (Northern) 187 
- Population used for MWRA sewer charge: (Northern) 554,031 
- Sewered population used for MWRA sewer charge: (Northern) 552,645 
Number 
of
community operated pump/lift stations: (Northern) 9* -
(4 sanitary, 4 storm and 1 combined) 
None - DEP Administrative Order Number: 
* Total Population: 675,647 (2020 US Census)
BWSC Estimated Sewered Population: 673,957 (FY23 Customer Service Update)
2022 MWRA Municipal Permit Application: 263 Connections (190 Public/ 73 Special)

3. 
Boston Infiltration/Inflow Estimates 
Total Wastewater Flow (MGD)
Sanitary Flow (MGD)
Ave. Annual Infiltration (MGD)
Ave. Annual Inflow (MGD)
Ave. Annual I/I (MGD) 
Ave. Annual Infiltration (GPD/IDM)
Ave. Annual Inflow (GPD/IDM)
Ave. Annual 1/1 (GPD/IDM)
Peak Month Infiltration (MGD)
Peak Month Infiltration (GPD/IDM)
Peak Month Inflow (MGD)
Peak Month Inflow (GPD/IDM)
Peak Month 1/1 (MGD)
Peak Month 1/1 (GPD/IDM) 
Annual Precipitation 0 2. Logan (Inches) 
MWRA MWRA MWRA Three Year 
CY19 CY20 CY22 Average 
96.43 77.60 78.39 84.,14 
58.50 54.91 57.54 56.98 
23.58 11.93 12.71 16.07 
14.36 10.76 8.13 11.08 
37.94 22.69 20.84 27.16 
1,681 850 854 1,129 
1,024 767 547 779 
2,705 1,618 1,401 1,908 
38.29 28.70 20.85 29.28 
2,730
22.97 
2,046
20.38 ,. 1,402
18.45 
2,059
20.60 
1,638 1,453 1,240 1,444 
61.26 49.08 39.30 49.88 
4,368 3,500 2,642 3,503 
50.38 36.33 52.33 46.35 
For more information on flow component estimates visit http://www.mwra.state.ma.us/harbor/pdf/infinf.pdf 
4. List of previously completed or ongoing 1/1 or SSES reports: 
Report 
A) SSES for Sewers Tributary to the East Side
Interceptor and Boston Main Interceptor 
B) I/I Analysis - Boston Wastewater Facilities Plan 
C) SSES - Phases I, II, & III . 
D) SSES - Allston/Brighton 
E) Ward Street Headworks SSES 
F) Inflow Survey for Large Impervious Areas /
Large Flat Roof Buildings 
G) • Longwood Medical Area I/1 Study 
H) West Roxbury Low Level Sewer 1/1 Analysis 
I) City-Wide I/I Analysis 
J) Dorchester SSES 
K) Allston Brighton SSES 
L) Jamaica Plain SSES 
Date 
January 1982 
fuly 1985
February 1989
July 199.7
June 2000
May 2005 
July 2009
October 2009
May 2017
January 2019
July 2021
ongoing 
Consultant 
CDM 
M&E
M&E
M&E
Weston & Sampson
Dufresne-Henry 
• Dewberry-Goodkind
BETA Group
CDM Smith
Tighe& Bond
Weston & Sampson
Wright-Pierce

5. Update on sewer rehabilitation projects and significant sewer maintenance activities over the last year.
Please estimate the peak or average annual infiltration and/or inflow removal (MGD) attributed to each
project listed, the source of the estimate, and the date of completion (actual or estimated). 
8/22: See Attachment B 
8/23: See Attachment B 
6~ Update on modifications and/or extensions of the collection system (other than those listed under
Item 5, above) over the last year:. 
8/22: See Attachment B 
8/22: See Attachment B 
7. Update on your House-to-House Inspection and Private Inflow Source Removal over the last year: 
8/22: Since the Downspout Disconnection Program began in 1994, approximately 38,000 building surveys
have been conducted, approximately 10,520 dye tests have been performed and approximately 26,329
downspouts have been disconnected City-wide. 
8/23: Since the Downspout Disconnection Program began in 1994, approximately 38,000 building surveys
have been conducted, approximately 10,520 dye tests have been performed and approximately 26,381
downspouts have been disconnected City-wide. 
8. Please provide specifics, if any, of the community's Developer Flow Reduction Program (2 for 1 type or
sewer connection fee), Sewer Bank or Enterprise Fund. 
8/22: The Commission does not have a Developer Flow Reduction program of its own, however it does
recognize DEP's guidelines for 4: 1 I/I removal. 
8/23: The Commission does not have a Developer Flow Reduction program of its own, however it does
recognize DEP's guidelines for 4:1 I/I removal.

9. Total MWRA 1/1 Local Financial Assistance (Grant/Loan) Program Update (Total System): 
Community Allocation Under Phases 1 - 14: $ 246,921,200 
Total Community Distribution: $122,344,709 
Total Funds Remaining: $ 124,576,491 
In May 2023, funds were distributed for the Jamaica Plain Sewer System Evaluatio~ Survey (BWSC Contract
No. 21-206-001 I MWRA Project No. WRA-P14-05-1-1412). 
In June 2022, funds were distributed for the Upper Roxbury Area Sewer Separation - Phase III Project (BWSC
Contract No. 17-309-001 / MWRA Project No. WRA-Pl 1-05-3-1189). 
In April 2021, funds were distributed for the East Boston Sewer Separation - Phase III Project (BWSC Contract
No. 19-309-002 I MWRA Project No. WRA-Pl 1-05-3-1180). 
In April 2021, funds were distributed for the South Boston Sewer Separation - Phase I Project (BWSC Contract
No. 20-309-012 I MWRA Project No. WRA-Pl 1-05-3-1171). 
In August 2019, funds were distributed for East Boston Sewer Separation - Phase II Project (BWSC Contract
No. 17-309-005 I MWRA Project No. WRA-Pl 1-05-3-1121). 
In August 2018, funds were distributed for the East Boston Sewer Separation - Phase I Project (BWSC Contract
No. 16-309-005 I MWRA Project No. WRA-P9-05-3-988).

ATTACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
1. BWSC PROJECT 94-309-008, East Boston Separation including construction of a separate sewer and
drain system in Waldemar A venue in East Boston. 
Estimated Peak Inflow Reduction is 16.2 MGD.
Construction was completed in 1996. 
2. BWSC PROJECT 92-309-024 (91-61 SD), Construction of separate system at Monument Street in
Charlestown. 
Estimated Peak Inflow Reduction is 0.5 MGD.
Construction was completed in 1992. 
3. BWSC PROJECT 92-309-006 (Neponset No. 1), Construction of drainage system at Mercier Street and
Codman Street in Dorchester. 
Estimated Peak Inflow Reduction is 1.3 MGD.
Construction was completed in 1993. 
4. BWSC PROJECT 90-61 SD (Neponset No. 2), Construction of drainage system at Dorchester Avenue,
Clearwater Drive, Lenoxdale Street and Granite Avenue in Dorchester. 
Estimated Peak Inflow Reduction is 4.5 MGD.
Construction was completed in 1992 . 
.5. BWSC PROJECT 90-64 SD, Construction of storm drain system in Washington Street, Jamaica Plain
from the Arborway to Columbus Avenue in West Roxbury. 
Estimated Peak Inflow Reduction is 10.0 MGD.
Construction was completed in 1992. 
B -1

ATTACHMENTB 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
6. BWSC 91-77 SD, Replacement of 6 existing tidegates. 
Estimated Peak Inflow Reduction is N/A.
Construction was completed in 1992. 
New tidegates were installed at the following locations: 
TG-1 Marginal Street at Ruth Street, East Boston
TG-2 Marginal Street at Cottage Street, East Boston
TG-3 Summer Street at New Street, East Boston
TG-4 Border Street at Decatur Street, East Boston
TG-5 Border Street at Eutaw Street, East Boston
TG-6&7 Eastern Avenue at Commercial Street, City Proper 
7. BWSC PROJECT 90-67 SD, Replacement of7 existing tidegates in the City Proper, Charlestown, South
Boston, Roxbury and Dorchester. 
Construction was completed in 1992. 
8. BWSC PROJECT 90-66 SD, Replacement of 9 existing tidegates in East Boston, South Boston and
North End. 
Construction was completed in 1990. 
9. BWSC PROJECT 90-51 SD, Rehabilitation of existing building sewers in Brimmer Street. 
Estimated Peak Inflow Reduction is 0.2 MGD.
Project was canceled. 
10. BWSC PROJECT 93-309-014, Rehabilitation of existing sewer and drain in St. James Avenue by
microtunneling in the City Proper. 
Estimated Peak Inflow Reduction is 0.1 MGD.
Construction was completed in January 1997. 
B-2

AITACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS-NORTH SYSTEM 
11 . BWSC PROJECT 87-18 SD, Sewer Separation Project on Edgewater Drive in Hyde Park. 
Estimated Peak Inflow Reduction is 2.6 MGD (North Portion).
Construction was completed in May 1989. 
12. BWSC PROJECT SD-3, Sewer Separation Project on East Berkeley Street in the South End. 
Estimated Peak Inflow Reduction is 9.3 MGD.
Construction was completed in 1988. 
13 . BWSC PROJECT SD-7, Sewer Separation Project on East Brookline Street, East Newton Street and
Paul Sullivan Way in the South End. 
Estimated Peak Inflow Reduction is 2.5 MGD.
Construction was completed in September 1989. 
14. BWSC PROJECT SD-8, Sewer Separation Project on Albany Street, East Dedham Street, Plympton
Street and Wareham Street in the South End. 
Estimated Peak Inflow Reduction is 4.9 MGD.
Construction was completed in September 1989. 
15. BWSC PROJECT SD-9, Sewer Separation Project on Washington Street, Perry Street, Savoy Street,
Rollins Street and Waltham Street in the South End. 
Estimated Peak Inflow Reduction is 5.5 MGD.
Construction was completed in September 1989. 
16. BWSC PROJECT SD-10, Sewer Separation Project on Washington Street, East Newton Street, and
Georges Street in the South End of Boston. 
St. 
Estimated Peak Inflow Reduction is 6.8 MGD.
Construction was completed in September 1989. 
B - 3

ATTACHMENTB 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
17. BWSC PROJECT SD-11, Sewer Separation Project in Worcester Square on E. Springfield Street in the
South End. 
Estimated Peak Inflow Reduction is 3.0 MGD.
Construction was completed December 1990. 
18. BWSC PROJECT SD-16, Sewer Separation Project on North Hampton Street in the South End. 
Estimated Peak Inflow Reduction is 3.3 MGD.
Construction was completed in October 1992. 
19. BWSC PROJECT SD-17, Sewer Separation Project on Harrison Avenue in the South End. 
Estimated Peak Inflow Reduction is 4.1 MGD.
Construction was completed in 1992. 
20. BWSC PROJECT MDPH #lX-95-1, Sewer Separation Project on Huntington Avenue in Roxbury. 
Estimated Peak Inflow Reduction is 17.7 MGD.
Construction was completed in 1989. 
21. BWSC PROJECT 81-7 SD, Sewer Separation Project on Stockton and Rockwell Streets in Dorchester. 
Estimated Peak Inflow Reduction is 3.1 MGD.
Construction was completed in 1987. 
22. BWSC PROJECT 83-38 SD, Sewer Separation Project on Hilltop and Ventura Streets in Dorchester. 
Estimated Peak Inflow Reduction is 1. 7 MGD.
Construction was completed in 1986. 
B-4

ATTACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS-NORTH SYSTEM 
23. BWSC 92-309-018 (92-81 SD), Replacement of 6 existing tidegates in South Boston. 
Construction was completed in 1994. 
New tidegates were installed at the following locations: 
TG-082-1 Farragut Road at E. Sixth Street 
TG-082-1 Day Boulevard at "N" Street 
TG-086-2 Old Colony Blvd. at Logan Way 
TG-086-3 Old Colony Blvd. at Logan Way 
TG-086-5 Old Colony Blvd. at Gavin Way 
TG-086-6 Old Colony Blvd. at Gavin Way 
24. BWSC PROJECT 93-309-007, Reconstruction of East Boston Low Level Sewer. 
Estimated Peak 1/1 Reduction is 3.3 MGD.
Construction was completed in 1993. 
25. BWSC PROJECT 92-309-004 (92-55 SD), Reconstruction of sanitary sewers on Commonwealth
Avenue in Brighton. 
Estimated Peak 1/1 Reduction is 0.02 MGD.
Construction was completed in 1993. 
26. BWSC PROJECT "MAINTENANCE", Replacement of defective manhole covers along with sanitary
sewer line repairs. 
Estimated Peak 1/1 Reduction is 0.02 MGD.
Construction completed in December 1996. 
27. BWSC PROJECT 90-77 SD, Rehabilitation of South Boston Interceptor. 
Estimated Peak 1/1 Reduction is 4.2 MGD.
Construction was completed in 1993. 
B-5

ATTACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS-NORTH SYSTEM 
28. BWSC PROJECT 93-309-013, Replacement of six (6) existing tidegates in Roxbury and South
Boston. 
Construction was completed in 1995. 
New tidegates were installed at the following locations: 
TG-064-1 Summer Street at Dorchester Avenue.
TG-070-6-2 Massachusetts Avenue at Melnea Cass Blvd.
TG-070-8-2 Dorchester Avenue at "D" Street.
TG-076-1-1 Pappas Road.
TG-078-1 East First Street at "I" Street.
TG-079-2 East First Street at Summer Street. 
29. BWSC PROJECT 94-309-006, Replacement of three (3) existing tidegates in South Boston.
Construction was completed in 1995.
New tidegates were installed at the following locations:
TG-073-3 Mt. Washington Avenue@ "A" Street 
TG-076-3-1 "D" Street between W. First Street and Claflin Street
TG-076-3-2 "D" Street Between W. First Street and Claflin Street 
30. BWSC PROJECT 93-309-008, Reconstruction of Boston Main Interceptor in Roxbury/Dorchester. 
Estimated Peak I/I Reduction is 0.1 MGD.
Construction was completed in 1995. 
B - 6

ATTACHMENT B
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
31. BWSC PROJECT 95-309-007, Replacement of eight (8) existing tidegates in East Boston I Roxbury. 
Construction was completed in 1997.
New tidegates were installed in the following locations: 
TG-003-1 Maverick and Cottage Streets.
TG-161(003) Orleans and Porter Streets.
TG-003-16 (2 gates) Bremen and Porter Streets.
TG-231-(046) Shawmut Avenue and Ruggles Street.
TG-046-47 Huntington Avenue and Parker Street.
TG-:046-58 Huntington Avenue and Forsyth Street.
TG-046-100 Lamartine Street and Paul Gore Street. 
32. BWSC PROJECT 95-309-008, Sewer Separation Project on Washington Street, Nantasket Street,
Arlington Street, Bennett Street, North Beacon Street, Vineland Street and Parson Street, Brighton
(Brighton Separation No. 1). 
Estimated Peak Inflow reduction is 14.0 MGD.
Construction was completed in 1996. 
33. BWSC PROJECT 95-309-009, Sewer Separation Project on Allston Street, Brainard Street,
Cambridge Street, · Emery Street, Penniman Street, Ridgemont Street, Saunders Street and Wilton
Street, Brighton (Brighton Separation No. 2). 
Estimated Peak Inflow Reduction is 12.3 MGD.
Construction was completed in 1996. 
34. BWSC PROJECT 95-309-010, Sewer Separation Project on "D" Street, South Boston. 
Estimated Peak Inflow Reduction is 1.6 MGD.
Construction was completed in 1996. 
35. BWSC PROJECT 95-309-014, Sewer Separation Project on Union Street, Boston Proper. 
Estimated Peak Inflow Reduction is 0.7 MGD.
Construction was completed in 1996. 
B-7

ATTACHMENT B
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
36. BWSC PROJECT 95-309-001, Sewer Separation Project on Terrace Stre~t; Roxbury. 
Estimated Peak Inflow Reduction is 6.8 MGD:
Construction was completed in 1996. 
37. BWSC PROJECT 95-308-002, Sewer Separation Project on Minot Street, Dorchester. 
Estimated Peak Inflow Reduction is 1.4 MGD.
Construction was completed in 1996. 
38. BWSC PROJECT 95-309-015, Sewer Separation Project in Port Norfolk, Dorchester. 
Estimated Peak Innow Reduction is 7.0 MGD.
Construction was completed in 1996. 
39. BWSC PROJECT 96-309-001, Separation Project in Archdale Road and Delford Street, Roslindale. 
Estimated Peak Inflow Reduction is 0.2 MGD.
Construction was completed in 1996. 
40. BWSC PROJECT 97-309-015, Combined with BWSC Project 97-309-016. 
41. BWSC PROJECT 97-309-016, (Neponset Area Separation), Sewer Separation Project in
South Dorchester tributary to the Neponset River. 
Estimated Peak Inflow Reduction is 17.5 MGD.
Construction was completed in July 1999. 
42. BWSC PROJECT 96-308-004, Installation of Storm Drain in Holbrook A venue in Dorchester. 
Estimated Peak Inflow Reduction is 0.1 MGD.
Construction was completed in April 1999. 
43. BWSC PROJECT 95-309-004, Installation of Sewer and Drain in Roxbury. 
Estimated Peak Inflow Reduction is 0.3 MGD.
Construction was, completed in 1997. 
B- 8 
ATTACHMENTB

BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
44. BWSC PROJECT 97-309-011, Sewer Separation Project in Brighton. 
Estimated Peak Inflow Reduction is 18.0 MGD.
Construction was completed in June 2001. 
45. BWSC PROJECT 97-309-004, Relining of sanitary sewer on Northern Avenue, South Boston. 
Estimated Peak 1/1 Reduction is 18.1 MGD.
Construction was completed in December 1998. 
46. BWSC PROJECT 98-309-004, Relining of sanitary sewer on Central Wharf. 
Estimated Peak Inflow Reduction: NIA. 
Construction was completed in January 1999. 
47. BWSC PROJECT 97-308-001, Sewer Separation on Bennington Street in East Boston and Stanhope
Street in Boston. 
Estimated Peak Inflow Reduction is N/A.
Construction was completed in August 1999. 
48. BWSC PROJECT 98-309-013, Relining of Sanitary Sewers in Charlestown Navy Yard. 
Estimated Peak I/I Reduction is 1.4 MGD.
Construction was completed in June 2002. 
49. STONY BROOK SEPARATION PROJECT, Separation of all combined sewers in the Stony Brook
Conduit tributary area. 
Estimated Peak Inflow Reduction is 137.0 MGD.
Construction was completed in September 2006. 
50. BWSC PROJECT 99-309-008, Tidegate Replacement in the Charlestown Navy Yard. 
Estimated Peak Inflow Reduction was not calculated.
Project Construction was completed in February 2000. 
B-9 
ATTACHMENT B

BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
51. BWSC PROJECT 99-309-010, East Boston Sewer Separation. 
Estimated Peak.Inflow Reduction is 11.2 MGD.
Construction was completed in October 2000. 
52. BWSC PROJECT 99-309-021, Downspout Disconnection in Neponset and East Boston. 
Estimated Peak Inflow Reduction was not calculated.
Construction was completed in July 2002. 
53 . DORCHESTER SEWER SEPARATION BOS090. 
Estimated Peak Inflow Reduction is 219.2 MGD.
Construction was completed in December 2006. 
54. DORCHESTER SEWER SEPARATION BOS 088 / 089. 
Estimated Peak Inflow Reduction is 174.2 MGD.
Construction was completed in May 2006. 
55 . BWSC PROJECT 00-309-009, Brighton Sewer Separation IV. 
Estimated Peak Inflow Reduction is 25.0 MGD.
Construction was completed in August 2006 .. 
56. MERRIMAC STREET SEWER RECONSTRUCTION. 
Estimated Peak I/I Reduction is 24.0 MGD.
Construction was completed in July 2003. 
57. WASIDNGTON STREET DRAINAGE PHASE IV. 
Estimated Peak 1/1 Reduction is 0.5 MGD.
Construction was completed in July 2002. 
58. BWSC PROJECT 01-309-005, Talbot Avenue Area I/I Removal. 
Estimated Peak I/I Reduction is 6.7 MGD.
Construction was completed in December 2003. 
B - 10 
ATTACHMENTB

BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
59. BWSC PROJECT KILMARNOCK STREET DRAIN. 
Estimated Peak I/I Reduction is 0.6 MGD.
Construction was completed in April 2005. 
60. BWSC PROJECT 02-309-013, Commercial Street 1/1 Removal (North End). 
Estimated Peak 1/1 Reduction is 0.2 MGD.
Construction was completed in September 2005. 
61 . BWSC PROJECT 03-309-007, Shawmut Avenue Drain (Roxbury) 
Estimated Peak 1/1 Reduction is 82.0 MGD.
Construction was completed in January 2005. 
62. D STREET AND WEST SECOND STREET SEWER AND DRAIN. 
Estimated Peak 1/1 Reduction is 9.0 MGD.
Construction was completed in July 2004. 
63. BWSC PROJECT 01-309-015, Tidegate Restoration. 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in June 2004. 
64. BWSC PROJECT 01-309-010, Large Commercial Properties in Neponset. 
Estimated Peak 1 /1 Reduction was not calculated.
Construction was completed in December 2005. 
65. BWSC PROJECT 01-309-009, 02-309-008, 03-309-009, South End Sewer. 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in December 2006. 
66. BWSC PROJECT 03-309-013, Causeway Street Separation. 
Estimated Peak 1/1 Reduction is 38.3 cfs.
Construction was completed in January 2005. 
B - 11

ATTACHMENTB 
BWSC SEWER SYSTEM REHABILITATION PROJECTS -NORTH SYSTEM 
67. BWSC PROJECT 02-308-009, Sewer Separation, Marginal Street (East Boston). 
Estimated Peak 1/1 Reduction is 10.8 MGD.
Construction was completed in September 2007. 
68. BWSC PROJECT 03-309-006, St. Botolph Street Area Sewer Rehabilitation (Copley Square). 
Estimated Peak 1/1 Reduction is 3.4 MGD.
Construction was completed in May 2007. 
69. BWSC MULTIPLE CONTRACTS-East Boston. 
Estimated Peak 1/1 Reduction is 8.0 MGD.
Construction was completed in April 2006. 
70. BWSC PROJECT 04-309-009, Chester Park Area (South End). 
Estimated Peak 1/1 Reduction is 0.06 MGD.
Construction was completed in July 2008. 
71. BWSC PROJECT 05-309-010, West Side Interceptor Lining (Beacon/Charles Sts). 
Estimated Peak 1/1 Reduction is 0.3 MGD.
Construction was completed in November 2007. 
72. BWSC PROJECT 05-309-002, Back Street Sewer Separation. 
Estimated Peak 1/1 Reduction is 0.03 MGD.
Construction was completed in July 2008. 
73. BWSC PROJECT 06-309-005, Albany Street/Melnea Cass Blvd. Area (Roxbury). 
Estimated Peak 1/1 Reduction is 5.0 MGD.
Construction was completed-in September 2010. 
74. BWSC PROJECT 07-308-010, Border Street and Condor Street in East Boston. 
Estimated Peak 1/1 Reduction is 52.0 MGD.
Construction was completed in September 2010. 
B-12

ATTACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
75. BWSC PROJECT 05-309-005, Harrison Avenue Separation (South End). 
Estimated Peak 1/1 Reduction is 4.7 MGD.
Construction was completed in September 2010. 
76. BWSC PROJECT 07-309-002, Catch Basin Reconnection (Dorchester/Mattapan/West Roxbury). 
Estimated Peak I/I Reduction is 0.8 MGD.
Construction was completed in February 2009. 
77. BWSC PROJECT 08-309-006, Marginal Street Rehabilitation (East Boston). 
Estimated Peak 1/1 Reduction is 10.8 MGD.
Construction was completed in April 2010. 
78. BWSC PROJECT 08-309-002, Lining Sewers (Back Bay/Beacon Hill/Dorchester/South End). 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in September 2010. 
79. BWSC PROJECT 08-309-001, Relay and Lining Sewers (Back Bay/East Boston/Kenmore/South End). 
Estimated Peak III Reductionis 1.0 MGD.
Construction was completed in December 2013. 
80. BWSC PROJECT 09-309-001, Relay and Reline Pipes (Back Bay/Dorchester/Hyde Park/Mattapan). 
Estimated Peak III Reduction is 0.4 MGD.
Construction was completed in A pril 2015. 
81. BWSC PROJECT 10-309-001, Relay and Reline Pipes (New Market Area - Lower Roxbury). 
Estimated Peak III Reduction was not calculated.
Construction was completed in August 2012. 
82. BWSC PROJECT 11-309-001, Relay and Reline Pipes (various locations). 
Estimated Peak III Reduction was not calculated.
Construction was completed in August 2013. 
B-13

I.. 
ATTACHMENT B
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
83. BWSC PROJECT 10-309-013, New Market Square Area Separation (Lower Roxbury). 
Estimated Peak I/I Reduction is 5.9 MGD.
Construction was completed in April 2012. 
84. BWSC PROJECT 10-309-012, Public Garden Lining. 
Estimated Peak I/I Reduction was not calculated.
Construction was completed in April 2011. 
85. BWSC PROJECT 12-309-004, New Market Square Separation (Mass Ave - Roxbury). 
Estimated Peak I/I Reduction is 29.7 MGD.
Construction was completed in April 2015. 
86. BWSC PROJECT 12-309-008, New Market Square Separation Area (Mass Ave - Dorchester). 
Estimated Peak I/I Reduction is 15.3 MGD.
Construction was completed in September 2013. 
87. BWSC PROJECT 11-309-009, Dudley Square Sewer Separation (Roxbury). 
Estimated Peak I/I Reduction is 58.0 MGD.
Construction was completed in December 2014. 
88. BWSC PROJECT 11-309-008, Audubon Circle/ Saint Mary's Street Area Separation. 
Estimated Peak I/I Reduction is 13.0 MGD.
Construction was completed in June 2013. 
89. BWSC PROJECT 12-309-001, Replacement of Sewer and Drain Pipes {various locations). 
Estimated Peak I/I Reduction was not calculated.
Construction was completed in September 2014. 
90. BWSC PROJECT 12-309-009, A Street Sewer Separation - South Boston @ Gillette Headquarters. 
Estimated Peak 1/1 Reduction is 14.4 MGD.
Construction was completed in December 2014. 
B-14

ATTACHMENTB
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
91. BWSC PROJECT 10-309-004, East Boston Separation. 
Estimated Peak I/I Reduction is 9.0 MGD.
Construction was completed in July 2012. 
92. BWSC PROJECT 13-309-006, Hampden Street Separation. 
Estimated Peak I/1 Reduction is 35.9 MGD.
Construction was completed in June 2016. 
93. BWSC PROJECT 15-309-005, West Side Interceptor Lining (Charles Street). 
Estimated Peak I/I Reduction was not calculated.
Construction was completed in August 2016. 
94. BWSC PROJECT 15-309-011, Upper Roxbury Area Sewer Separation - Phase I. 
Estimated Peak I/I Reduction is 15. 7 MGD.
Construction was completed in October 2018. 
95. BWSC PROJECT 16-309-005, East Boston Sewer Separation - Phase I. (MWRA 988) 
Estimated Peak I/I Reduction is 19.0 MGD.
Construction was completed December 2021. 
96. BWSC PROJECT 16-309-011, Upper Roxbury Area Sewer Separation - Phase II. (MWRA 969) 
Estimated Peak I/I Reduction is 23.0 MGD.
Construction was completed in June 2020. 
97. BWSC PROJECT 17-309-013, Fairfield Street Sewer Rehabilitation. (MWRA 968) 
Estimated Peak I/I Reduction is 0.03 MGD.
Construction was completed in February 2018. 
98. BWSC PROJECT 17-309-005, East Boston Sewer Separation - Phase II. (MWRA 1121) 
Estimated Peak I/I Reduction is 3.0 MGb.
Construction was completed in September 2021. 
99. BWSC PROJECT 20-309-012, South Boston Sewer Separation - Phase I. (MWRA 1171) 
Estimated Peak I/I Reduction is 3.0 MGD.
Construction is scheduled for completion in April 2024. 
B - 15

ATTACHMENT B 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - NORTH SYSTEM 
100. BWSC PROJECT 19-309-002, East Boston Sewer Separation - Phase III. (MWRA 1180) 
Estimat.ed Peak 1/1 Reduction is 16.4 MGD.
Construction is scheduled for completion in August 2024. 
101. BWSC PROJECT 17-309-011, Upper Roxbury Area Sewer Separation- Phase III. (MWRA 1189) 
Estimated Peak 1/1 Reduction is 23.0 MGD.
Construction is scheduled for completion in May 2024. 
102. BWSC PROJECT 19"."309-003, Replacement and Rehabilitation of Sewers in Dorchester
Estimated Peak 1/1 Reduction is 0.44 MGD
Construction was completed in May 2021. 
102. BWSC PROJECT 17-309-014, Sewer and Drain Pipe Replacement and Rehabilitation City-Wide
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in May 2021. 
B - l6

BOSTON WATER AND SEWER COMMISSION
SOUTHERN SYSTEM 
MWRA ANNUAL 1/1 QUESTIONNAIRE 
(To be submitted to MWRA Community Support Program by July 28, 2023)
Community Support Contact: Jon Szarek, P .E.
(617) 788-4358 or jon.szarek@mwra.com 
NAME: ___ -----r A~d=a = m =-= H """ o -= rs """" t~Ju=l'-'-y--= 6 '-'-,= 2-= 02=3'------- ---- ------ - 
Name of Person Updating Questionnaire and Date 
1. Contact Person for 1/1 Issues: 
John Sullivan, Chief Engineer Charlie Jewe11, Director of Planning 
Boston Water and Sewer Commission Boston Water and Sewer Commission 
980 Harrison Avenue 980 Harrison Avenue 
Boston, MA 02119 (61 7) 989-7444 Boston,MA 02119 (617)989-7431 
2. General Information on Sewer System: 
- Miles of separate sanitary sewers: (Southern) 270 
- Miles of combined sewers: (Southern) 0 
- Total miles of sewers (Total System): 854 
- Inch miles of sewers (Total System): 14,876 
- Number of service connections: (Southern) 20,902 
- Number of connections to MWRA System: (Southern) 48 
- Population used for MWRA sewer charge: (Southern) 121,616 
- Sewered population used for MWRA sewer charge: (Southern) 121,312 
- Number of community operated pump/lift stations: (Southern) 0 
- DEP Administrative Order Number: None 
* Total Population: 675,647 (2020 US Census) 
BWSC Estimated Sewered Population: 673,957 (FY23 Customer Service Update)
2022 MWRA Municipal Permit Application: 263 Connections (190 Public/ 73 Special)

3. 
Boston Infiltration/Inflow Estimates MWRA MWRA MWRA Three Year 
CY18 CY19 CY20 Average 
Total Wastewater Flow (MGD) 98.64 96.43 77.60 90.89 
Sanitary Flow (MGD) 58.50 58.50 54.91 57.30 
Ave. Annual Infiltration (MGD) 23.52 23.58 11.93 19.68 
Ave. Annual Inflow (MGD) 16'.62 14.36 10.76 13.91 
Ave. Annual I/I (MGD) 40.14 37.94 22.69 33.,59 
Ave. Annual Infiltration (GPD/IDM) 1,677 1,681 850 1,403 
Ave. Annual Inflow (GPD/IDM) 1,185 1,024 767 992 
Ave. Annual I/I (GPD/IDM) 2,862 2,705 1,618 2,395 
Peale Month Infiltration (MGD) 40.88 38.29 28.70 35.96 
Peale Month Infiltration (GPD/IDM) 2,915 2,730 2,046 2,564 
Peak Month Inflow (MGD) 52.92 225/7 20.38 32.09 
Peak Month Inflow (GPD/IDM) 3,774 1,638 1,453 2,288 
Peale Month VI (MGD) 93.80 61.26 49.08 68.05 
Peak Month VI (GPD/IDM) 6,689 4,368 3,500 4,852 
Annual Precipitation @, Logan (Inches) 53.32 50.38 36.33 46.68 
For more information on flow component estimates visit http://www.mwra.state.ma.us/harbor/pdf/infinf. pdf 
4. List of previously completed o_r ongoing 1/1 or SSES reports: 
Report Date Consultant 
A) SSES for Sewers Tributary to the East Side January 1982 CDM 
Interceptor and Boston Main Interceptor 
B) I/I Analysis - Boston Wastewater Facilities Plan July 1985 M&E 
C) SSES - Phases I, II, & III February 1989 M&E 
D) SSES in 15 Trib. Areas; Flow Isolation
Gauging, Smoke Testing & Public 
February 1991 1 RJN Env. Assoc. 
Sector Dye Water Flooding 
F) SSES in 15 Trib. Areas- Dye Tracing October 1991 RJN Epv. Assoc. 
w/TV Inspection 
G) Private Sector Inflow Survey July 1994 RJN Group 
H) Roslindale Interceptor Inflow Survey November 1999 Dufresne-Henry 
I) Talbot A venue High Level SSES . April2000 Dufresne-Henry 
J) Upper Neponset Valley Sewer Inflow Survey November 2005 Malcolm Pirnie 
K) Dorchester High Level Sewer I/I Surv,ey September 2006 Weston & Sampson 
L) Granite Avenue Area (NVS) I/I Study September 2007 Stantec Consulting 
M) Lower Dorchester Brook Sewer Study October 2007 Tetra Tech Rizzo 
N) City-Wide I/I Analysis May2017 COM Smith 
0) Dorchester SSES January 2019 Tighe& Bond 
P) Roslindale SSES May2020 CDMSrilith 
Q) Mattapan SSES February 2022 CDM Smith

5. Update on sewer rehabilitation projects and significant sewer maintenance activities over the last year.
Please estimate the peak or average annual infiltration and/or inflow removal (MGD) attributed to each
project listed, the source of the estimate, and the date of completion (actual or estimated). 
8/22: See Attachment A 
8/23: See Attachment A 
6. Update on modifications and/or extensions of the collection system (other than those listed under
Item 5, above) over the last year: 
8/22: See Attachment A 
8/23: See Attachment A 
7. Update on your Bouse-to-Bouse Inspection and Private Inflow Source Removal over the last year: 
8/22: Since the Downspout Disconnection Program began in 1994, approximately 38,000 building surveys
have been conducted, approximately I 0,520 dye tests have been performed and approximately 26,329
downspouts have been disconnected City-wide. 
8/23: Since the Downspout Disconnection Program began in 1994, approximately 38,000 building surveys
have been conducted, approximately 10,520 dye tests have been performed and approximately 26,381
downspouts have been disconnected City-wide. 
8. Please provide specifics, if any, of the community's Developer Flow Reduction Program (2 for 1 type or
sewer connection fee), Sewer Bank or Enterprise Fund. 
8/22: The Commission does not have a Developer Flow Reduction program of its own, however it does
recognize DEP's guidelines for 4: I I/I removal, 
8/23: The Commission does not have a Developer Flow Reduction program of its own, however it does
recognize DEP's guidelines for 4:1 1/1 removal.

ATTACHMENT A 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
1. BWSC PROJECT 90-82 SD, Separation of twenty-one (21) catch basins in the South System along with
sanitary manhole rehabilitation. 
Estimated Peak Inflow Reduction is 4.2 MGD.
Construction was completed in 1992. 
2. BWSC PROJECT 90-81 SD, Separation of thirty-one (31) catch basins in the South System along with
sanitary manhole rehabilitation. 
Estimated Peak Inflow Reduction is 2.9 MGD.
Construction was completed in 1991. 
3. BWSC PROJECT 90-80 SD, Separation of fifteen (15) catch basins in the South System. 
Estimated Peak Inflow Reduction is 0.2 MGD.
Construction was completed in 1990. 
4. BWSC PROJECT 90-69 SD, Sewer Separation Project on Beech Street in Roslindale. 
Estimated Peak Inflow Reduction is 1.7 MGD.
Construction was completed in November 1990. 
5. BWSC PROJECT 89-50 SD, Rosliridale Square Sewer Separation Project on South Street, Popular
Street, Tafthill Road and Washington Street. 
Estimated Peak Inflow Reduction is 0.6 MGD.
Construction was completed in 1990. 
6. BWSC PROJECT 88-26 SD, Separation of twenty-six (26) catch basins in the South System. 
Estimated Peak Inflow Reduction is 0.2 MGD.
Construction was completed in September 1989. 
7. BWSC PROJECT 88-26A SD, Separation of fifteen (15) catch basins in the South System. 
Estimate Peak Inflow Reduction is 0.2 MGD.
Construction was completed in September 1989. 
8. BWSC PROJECT 87-25 SD, Sewer Separation Project on River Street (Cleary Square) in Hyde Park. 
Estimated Peak Inflow Reduction is 0.7 MGD.
Construction was completed in 1988.

A- 1 
ATTACHMENT A 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
9. BWSC PROJECT 87-19 SD, Partial Sewer Separation Project on Metropolitan Avenue in Hyde Park. 
Estimated Peak Inflow Reduction is 0.7 MGD.
Construction was completed in May 1989. 
10. BWSC PROJECT 87-18 SD, Sewer Separation Project on Edgewater Drive in Hyde Park. 
Estimated Peak Inflow Reduction is 4.2 MGD (South Portion).
Construction was completed in May 1989. 
11 . BWSC PROJECT 87-17 SD, Sewer Separation Project on Sunnyside Street in Hyde Park. 
Estimated Peak Inflow Reduction is 4.9 MGD.
Construction was completed in 1988. 
12. BWSC PROJECT 87-15 SD, I/I Rehabilitation Project on Providence Street in Hyde Park. 
Estimated Peak I/I Reduction is 5.2 MGD.
Construction was completed in June 1989. 
13 . BWSC PROJECT "MAINTENANCE", Replacement of defective manhole covers along with sanitary
sewer line repairs. 
Estimated Peak 1/1 Reduction is 0.02 MGD.
Replacement work completed in December 1996. 
14. BWSC PROJECT 91-84 SD, Sewer Separation Project on Factory Street Dana Avenue and Brush Hill
in Hyde Park. 
Estimated Peak Inflow Reduction is 2.0 MGD.
Construction was completed in 1992. 
15. BWSC PROJECT 93-309-018 (91-76 SD), Separation often (10) catch basins in the South System along
with 840 sanitary manhole rehabilitations. 
Estimated Peak I/I Reduction is 3.6 MGD.
Construction was completed in 1994. 
A-2

ATTACHMENT A
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
16. BWSC PROJECT 89-81 SD, I/I Rehabilitation of sanitary sewers on Danny Road, Morton and Seldon
Streets, Normandy Street, Osceola Street and Talbot Avenue High Level Sewer in Dorchester. 
Estimated Peak VI Reduction is 0.5 MGD.
Construction was completed in 1989. 
17. BWSC PROJECT 92-309-011 (92-56 SD), I/I Rehabilitation of sanitary sewers on Vogel Street and
Seanar Road, West Roxbury. 
Estimated Peak I/I Reduction is 2.0 MGD.
Construction was completed in 1993. 
18. BWSC PROJECT 92-309-017 (92-80 SD), Separation of fifteen (15) catch basins in addition to sanitary
sewer system rehabilitation in Dorchester/Roslindale. 
Estimated Peak I/I Reduction is 1.7 MGD.
Construction was completed in 1995. 
19. BWSC PROJECT 93-309-012, Sanitary sewer rehabilitation/separation in West Roxbury/Hyde Park. 
Estimated Peak Inflow Reduction is 1.7 MGD.
Project Construction was completed in 1995. 
20. BWSC PROJECT 94-309-016, Install new drain to separate flow from sanitary system near Walter Street
and Coniston Road in West Roxbury. 
Estimated Peak Inflow Reduction is 7.5 MGD.
Construction was completed in 1995. 
21 . BWSC PROJECT 94-309-009, Sanitary sewer rehabilitation/separation. 
Estimated Peak I/I Reduction is 2.0 MGD.
Construction was completed in 1995. 
22. DOWNSPOUT DISCONNECTION PROGRAM, Since the Downspout Disconnection Program began
in 1994, approximately 38,000 building surveys have been conducted, approximately 10,520 dye tests
have been performed and approximately 26,381 downspouts have been disconnected City-wide. 
Estimated Peak Inflow Reduction is 10.0 MGD.
Construction was completed in Julv 2000. 
A-3

ATTACHMENT A 
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
23. BWSC PROJECT 95-309-006, Sanitary sewer system rehabilitation in West Roxbury. 
Estimated Peak I/I Reduction is 8.0 MGD;
Project Construction was completed in 1997. 
24. BWSC PROJECT 95-309-018, Sanitary joint sealing in West Roxbury. 
Estimated Peak I/I Reduction is 0.2 MGD.
Project Construction was completed in 1996. 
25. BWSC PROJECT 96-309-006, Sewer System Rehabilitation (No. l} in Hyde Park. 
Estimated Peak I/I Reduction is 5.0 MGD.
Project Construction was completed in 1997. 
26. BWSC PROJECT 96-309-018, Sewer System Rehabilitation (No. 2) in Hyde Park. 
Estimated Peak I/I Reduction is 5.0 MGD.
Project Construction was completed in August 1998. 
27. BWSC PROJECT 95-309-009, Sewer Separation Project on Como Road and Readville Road,
Hyde Park. 
Estimated Peak Inflow Reduction is 0.6 MGD.
Project Construction was completed in 1996. 
28. BWSC PROJECT 98-309-008, Sewer Separation on Winslow Street and Child Street, Hyde Park. 
Estimated Peak Inflow Reduction is 1.8 MGD.
Project Construction was completed in April 2002. 
29. BWSC PROJECT 99-309-017, 
Lower East Street, Dedham. 
Sewer Separation Project on Centre Street, West Roxbury and 
Estimated Peak Inflow Reduction 11.0 MGD.
Project Construction was completed in December 2001.

A-4 
ATTACHMENT A
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
30. BWSC PROJECT 99-309-020, Roslindale Interceptor Downspout Disconnection Program. 
Estimated Peak Inflow Reduction is 0.5 MGD.
Construction was completed in December 2001. 
31. BWSC PROJECT 00-309-011, Roslindale & West Roxbury 1/1 Removal Program. 
Estimated Peak 1/1 Reduction is 2.9 MGD
Construction was completed in January 2002. 
32. BWSC PROJECT 04-309-001, Talbot Avenue High Level Sewer Area: Sewer/Drain Replacement with
Manhole Rehabilitation. 
Estimated Peak 1/1 Reduction is 3.8 MGD
Construction was completed in October 2007. 
33. BWSC PROJECT 08-309-001, Relay and Reline Pipes (various locations along Granite Avenue). 
Estimated Peak 1/1 Reduction is 1.0 MGD
Construction was completed in July 2011. 
34. BWSC PROJECT 09"'-309-001, Relay and Reline Pipes (various locations along Granite Avenue). 
Estimated Peak 1/1 Reduction is 0.4 MGD
Construction was completed in 2011. 
35. BWSC PROJECT 10-309-001, Relay and Reline Pipes (various locations). 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in September 2012. 
36. BWSC PROJECT 11-309-001, Relay and Reline Pipes (various locations). 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in August 2013. 
37. BWSC PROJECT 12-309-001, Replacement of Sewer and Drain Pipes (various locations). 
Estimated Peak 1/1 Reduction was not calculated.
Construction was completed in September 2014. 
A-5

ATTACHMENT A
BWSC SEWER SYSTEM REHABILITATION PROJECTS - SOUTH SYSTEM 
38. BWSC PROJECT 12-309-012, Removal of Stormwater Inflow Sources in Dorchester/Neponset. 
Estimated Peak I/I Reduction was not calculated.
Construction was completed in September 2014.

Jiltration/Inflow Estimates: Town Three 
Jtal System) I/I study MWRA MWRA MWRA Year 
1985 CY94 CY95 CY96 AVG 
Total Wastewater Flow (MGD) 110.82 97 .97 112.84 I 07.2 I 
Ave. Annual Infiltration (MGD) 41.17 35 .27 37.54 37.99 
Ave. Annual Infiltration (GPD/IDM) 2,936 2,515 2,677 2,709 
Ave. Annual Inflow (MGD) 16.61 10.19 22 .98 16.59 
Ave. Annual I/I (MGD) 57.78 45.46 60 .52 54.59 
Peak Month Infiltration (MGD) 54.88 47.55 49.72 50.72 
Peak Month Infiltration (GPD/IDM) 3,913 3,39 I 3,545 3,616 
Design Storm Peak Inflow Rate (MGD) 
4. List of previously completed or ongoing I/I or SSES reports: 
Report Type Consultant 
A) SSES for Sewers Tributary to the East Side
Interceptor and Boston Main Interceptor Jan. 1982 CDM 
B) I/I Analysis-Boston Wastewater Facilities Plan Jul. 1985 M&E 
C) SSES-Phases I, II, & III Feb. 1989 M&E 
D) SSES in Allston/Brighton Started in Nov. 1995 M&E 
5. Update on sewer rehabilitation projects and significant sewer maintenance activities over the last six months.
Please estimate the peak or average annual infiltration and/or inflow removal (MGD) attributed to each project
listed, the source of the estimate. and the date of completion (actual or estimated) : 
1996: SEE ATTACHMENT B 
1997 : 
6. Update on modifications and/or extensions of the collection system (other than those listed under item 5,
above) over the past six months: 
1996: SEE ATTACHMENT B