Please send an email to the State House to End Sewage Pollution.
Do you live near Alewife Brook? Do you use the Alewife Greenway Path or the Alewife Brook Reservation state park? Do you live, work, commute, or play near any of the other 35 Combined Sewer Outfalls in the MWRA’s system that discharge untreated sewage into the environment?
Please ask legislators to report favorably on House Bill 1031 and Senate Bill 608. Your personal stories are the best testimony. You can add your local legislators at the State House to the email. The deadline for comments is July 1st, 2025. So please do this today.
House Bill 1031 and Senate Bill 608 are identical. This law would require all CSOs in the MWRA’s sewer service area to end the dumping of untreated sewage during storms as large as a 25-year event, by 2035 at the latest. That is the effective elimination of CSOs, also referred to as “virtual CSO elimination.”
Save the Alewife Brook Goes to the State House!
David Stoff and Gene Benson are all smiles at the State House. Stoff’s Poop Emoji costume was on loan from the Charles River Watershed Association.
Testimony at the State House hearing on 06/17/2025.
Save the Alewife Brook’s Eugene Benson, Kristin Anderson, and Paige Gromfin provide testimony at the State House hearing.
Somerville’s Michael Lonetto provides testimony at the State House hearing.
Save the Alewife Brook’s David Stoff provides testimony at the State House hearing.
Mashpee Wampanoag Hartman Deetz testifies at the State House hearing.
Mystic River Watershed Association’s Patrick Herron and Charles River Watershed Association’s Emily Norton provide testimony at the State House hearing.
Why is this legislation necessary?
Improvements as a result of the Boston Harbor Cleanup have stalled. Climate change threatens to make sewage pollution four times worse by 2050. We have seen that the sewage polluters are planning to do the bare minimum. The bare minimum would allow untreated sewage to continue to be dumped into Alewife Brook in rainstorms. The state must step in to require ending sewage pollution in the Greater Boston area.
What does this legislation do?
House Bill H.1031 and the identical Senate Bill S.608 address the sewage pollution crisis in the Greater Boston area. It gives the MWRA and the cities of Cambridge, Somerville, Boston, and Chelsea 10 years to end untreated sewage pollution. The polluters can either install CSO treatment facilities or engineer solutions to eliminate sewage dumping in up to a 25-year storm. This is what MWRA calls a “25-year level of control.” The MWRA has done it before, in South Boston, so it is doable.
What is a “25-year storm?”
Today’s “25-year storm” has a 4% chance of occurring in any given year, statistically expected once every 25 years. That means around 6 inches of rain in 24-hours, according to NOAA Atlas 14 data.
For context: the last big storm was the May 22, 2025 nor’easter. In the Alewife area, it was not as big as a 10-year storm event. That storm produced 3.14 inches of rainfall in Cambridge. As a result of that rain, Cambridge’s Alewife MBTA CSO dumped 1.35 million gallons of raw sewage pollution into Alewife brook.
This legislation would require a solution where there is no sewage pollution in up to a storm that is twice as big at the 05/22/2025 nor’easter, OR construction of a CSO treatment facility to treat the sewage.
What is a CSO treatment facility?
A CSO treatment facility treats combined sewer overflows during storm events. It reduces pathogens with partial treatment (chlorination and then dechlorination), removes some solids, and somewhat improves water quality. It is not nearly as comprehensive as the treatment at the Deer Island treatment plant. But it is better than no treatment.
There are currently four CSO treatment facilities in the MWRA’s sewer system. Cambridge has a CSO treatment facility near Magazine Beach. The newest is MWRA’s Union Park CSO treatment facility, constructed in 2007 at a cost of $55 million. Union Park includes a 2.2 MG underground detention tank, with a public park above the tank.