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SENATE DOCKET, NO. 1118 FILED ON: 1/15/2025
SENATE . . . . . . . . . . . . . . No. 608
The Commonwealth of Massachusetts
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PRESENTED BY:
Patricia D. Jehlen
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To the Honorable Senate and House of Representatives of the Commonwealth of Massachusetts in General
Court assembled:
The undersigned legislators and/or citizens respectfully petition for the adoption of the accompanying bill:
An Act relative to combined sewer overflows.
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PETITION OF:
NAME:DISTRICT/ADDRESS :Patricia D. JehlenSecond Middlesex 1 of 3
SENATE DOCKET, NO. 1118 FILED ON: 1/15/2025
SENATE . . . . . . . . . . . . . . No. 608
By Ms. Jehlen, a petition (accompanied by bill, Senate, No. 608) of Patricia D. Jehlen relative to
combined sewer overflows. Environment and Natural Resources.
[SIMILAR MATTER FILED IN PREVIOUS SESSION
SEE HOUSE, NO. 886 OF 2023-2024.]
The Commonwealth of Massachusetts
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In the One Hundred and Ninety-Fourth General Court
(2025-2026)
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An Act relative to combined sewer overflows.
Be it enacted by the Senate and House of Representatives in General Court assembled, and by the authority
of the same, as follows:
1 Chapter 21 of the General Laws, as appearing in the 2022 Official Edition, is hereby
2amended by adding the following section:
3 Section 27B
4 a) As used in this Section, the following words and phrases shall have the following
5meanings unless the context clearly requires otherwise:
6 “Combined Sewer System” is a wastewater collection system of a municipality or of a
7Publicly Owned Treatment Works that conveys sanitary wastewaters (domestic, commercial, and
8industrial wastewaters) and storm water through a single-pipe system to a treatment plant. 2 of 3
9 “Combined Sewer Overflow” is a discharge or release from a Combined Sewer System
10directly or indirectly to a water of the commonwealth at a point prior to a Publicly Owned
11Treatment Works Treatment Plant.
12 “Publicly Owned Treatment Works” is a treatment works as defined by Section 212 of
13the Clean Water Act that is owned by a state or municipality as defined by Section 502(4) of the
14Clean Water Act, which includes the treatment works of the Massachusetts Water Resources
15Authority. This definition includes any devices and systems used in the storage, treatment,
16recycling, and reclamation of municipal sewage or industrial wastes of a liquid nature. It also
17includes sewers, pipes, and other conveyances that convey wastewater to a sewage treatment
18plant.
19 “Publicly Owned Treatment Works Treatment Plant” is that portion of the Publicly
20Owned Treatment Works that is designed to provide at least secondary treatment, including
21recycling and reclamation, of municipal sewage and industrial waste. That includes the
22Massachusetts Water Resources Treatment Plant at Deer Island.
23 “Untreated Combined Sewer Overflow” is a discharge or release that does not include at
24least the removal of solids and treatment to deactivate bacteria.
25 b) Beginning on January 1, 2035, in the Massachusetts Water Resources Authority sewer
26service areas set forth in Acts of 1984, chapter 372, Section 8(c), there shall be no untreated
27Combined Sewer Overflow in any 25-year 24-hour storm event or smaller storm event.
28 c) Within 18 months, the Department of Environmental Protection shall adopt regulations
29to implement this Section that shall include, but not be limited to, the definition of a 25-year 24-
30hour storm event, which it shall update from time to time as the climate changes, and a definition 3 of 3
31of Combined Sewer Overflow treatment that shall include at a minimum removal of solids and
32treatment to deactivate bacteria, which it shall update from time to time as technology changes.