Document Library

This is Save the Alewife Brook’s December 2025 letter to the MWRA Board of Directors. …

Save the Alewife Brook’s November 2025 comments on the updated sewage elimination plan. Includes a …

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Dewberry 2022 …

This document describes the founding principles of a coalition of community advocates and organizations created …

Download to see the Raw Sewage Control Plan Proposals for Alewife Brook from Cambridge, Somerville, …

The study confirms that large CSO events increase the risk of gastrointestinal illness in downstream …

The “Ending Alewife Sewage” policy order is a formal request from the Cambridge City Council …

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This is Save the Alewife Brook’s Honk 2024 flyer, for the festival and parade from …

This is three documents: 1. Save the Alewife Brook’s comments to the Arlington Select Board …

A Tour of the Alewife Brook Combined Sewer Outfalls From our CSOs 101 Course …

On Alewife Brook, behind Dilboy Park, under the Broadway Bridge, kayaking through a mass of …

FINAL DETERMINATION TO ADOPT A WATER QUALITY STANDARDS VARIANCE FOR COMBINED SEWER OVERFLOW DISCHARGES TO …

RESPONSE TO PUBLIC COMMENTS on TENTATIVE DETERMINATIONS TO ADOPT WATER QUALITY STANDARDS VARIANCES FOR COMBINED …

During heavy rainstorms, the Alewife Brook floods into the parks, yards, and houses of area residents in Environmental Justice Communities. The flood water contains hazardous sewage that is dumped into the Brook from the active Combined Sewer Overflows (CSOs) owned by Cambridge, Somerville, and the Massachusetts Water Resources Authority (MWRA).

Climate change, with its wetter rainy seasons, more intense storms, and sea level rise, is expected to increase the severity and frequency of these events. MWRA’s sewer infrastructure is failing to meet capacity during many rains, causing hazardous sewage pollution discharges.

In 2023, Alewife Brook flooded repeatedly, overtopping its banks and inundating the Greenway of Alewife Brook Reservation State Park with untreated Combined Sewer Overflow discharges of human and industrial waste. Area residents from Somerville, Cambridge, and Arlington unknowingly bicycled, jogged, and pushed baby strollers through untreated sewage flood water in their state park.

The Alewife Greenway Path is a heavily used transportation and recreation corridor that runs through multiple Environmental Justice neighborhoods. The Alewife Greenway Path is on DCR land and it links Medford, Somerville, and Arlington pedestrians and cyclists to the Alewife Red Line T stop.

In a combined sewer system, both wastewater and stormwater flow through the same pipes. In dry weather, all wastewater flows to a wastewater treatment plant where it is treated before being discharged to a waterbody. But during wet weather, stormwater also enters the system. The combined flow of wastewater and stormwater can overwhelm the system. Permitted outfalls are located throughout the system to act as relief points during wet weather. These outfalls discharge untreated or partially treated stormwater and wastewater into nearby waterbodies. These discharges are called CSOs.

CSOs are a major water pollution and public health concern for approximately 700 communities in the United States. CSOs can contain bacteria, debris, and other hazardous substances that can be harmful to people, pets, and wildlife. CSOs can also cause beach closures, shellfish bed closures, algae growth, reduced oxygen levels in waterways, and aesthetic impacts from floating debris or oil slicks. The Clean Water Act requires communities with CSOs to put controls in place to address these concerns.

from Alewife Brook CSOs 101 course material thank you to Mystic River Watershed …

This is MassDEP’s 2024 draft of the Water Quality Variance for Alewife Brook, which would …

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“CSO entities should not be awarded a new variance if they have failed to meet the requirements of the current variance. SOM001A has failed to meet discharge and floatable controls requirements. There must be some consequence for that. CAM401A continues to fail to conform to the hydraulic models. MWRA fails to adequately maintain its sewers to prevent odors. Further, granting the variance would undermine environmental justice principles, which call for enforcement of environmental standards and protection of environmental neighborhoods from environmental harms… MassDEP must add conditions to the Variance so that CSO discharges do not get worse — and to require improvements for CSOs while waiting for the new LTCP to be approved and implemented… The most obvious and necessary conditions to add to the variance are: 1) a prohibition on new hook ups to the combined sewers in Cambridge and Somerville that contribute to the CSOs in Alewife Brook; and 2) a prohibition on more than de minimis increases to current flows to those combined sewers… people using the Greenway path in the Alewife Brook Reservation and abutters of the brook require timely and clear warnings when CSOs are discharging into the brook and for at least 48 hours after a discharge has ended (e.g., red light when discharging and for 24 hours after discharge ends, yellow light for 24-48 hours after discharge ends, and green light if no discharges for more than 48 hours)… The variance should require that the project, “perform further system metering and hydraulic model calibration to improve CAM401A system understanding and address differences in current hydraulic models… The variance must require MWRA to create and implement an odor control program… The following sentence should be included: “For the Cities of Cambridge and Somerville, use of Green Infrastructure technologies shall be considered.” …Alewife Brook is adjacent to many environmental justice neighborhoods as defined by Massachusetts law… Requiring separate financial analyses from Cambridge, Somerville, and MWRA for their CSOs in Alewife Brook and how they might set different sewer rates that could cap rates or provide subsidies for low-income households that might not be able to afford higher rates… We suggest that Environmental Justice must include these measures that are discussed earlier in these comments:
• Requiring separate financial analyses from Cambridge, Somerville, and MWRA for their CSOs in Alewife Brook and how they might set different sewer rates that could cap rates or provide subsidies for low-income households that might not be able to afford higher rates, as discussed earlier in these comments. This is consistent with longstanding environmental justice principles that environmental justice communities should not bear the burden or costs of pollution that are beyond their control. This also allows MassDEP to reject the variance under its discretionary authority for variances as discussed earlier in these comments.
• Prohibiting new hook ups to the combined sewers that contribute to the CSOs and prohibiting no more than de minimis increases in flows to those sewers, as discussed earlier in these comments. That is consistent with not allowing an increase in environmental burdens to Environmental Justice neighborhoods.
• Clear and timely warnings when CSO activate, and odor control measures, as discussed earlier in these comments. These are important notice and mitigation measures.
• Providing reports to advocacy groups and online sewer maps, as discussed earlier in these comments. Notice and ability to participate depends on timely and complete access to information.
• The use of green infrastructure can enhance neighborhoods, especially those with little green space or trees. As discussed earlier, green infrastructure must be a consideration in meeting CSO goals.”

“problem CSO’s are characterized as “incorrigible.” The Honorable Judge Stearns writes in this decision that he “recognize(s), as MWRA posits, that there may come a point of diminishing return at which spending an additional $100 for a $1 incremental benefit would make no sense from a public policy view… Performing such a study (the Alewife Brook Updated CSO Control Plan) would be extremely expensive and may ultimately be unnecessary.”

“the public using the Alewife Brook Greenway and abutters of the Brook need much clearer warning when there are active CSO discharges, and for at least 24 hours after a discharge has ended (e.g., red light when discharging, yellow light for 24 hours after discharge ends). Subscriber-based notifications are insufficient for those who may be using the greenway. It is imperative to add requirements for MWRA, Cambridge, and Somerville to enhance notification by installing warning beacons or similar, highly visible signage when the outfalls on the Alewife Brook are discharging… MassDEP should add a condition requiring Cambridge and Somerville to limit future increases in sewage flows to current combined sewers discharging to the Alewife Brook/Upper Mystic during the term of the variance. This could take the form of a prohibition on new hook ups to the combined system,… Save the Alewife Brook has documented instances of failures of floatable controls at SOM001A. Odor control has also been an issue at manholes along the Greenway Path. MassDEP and EPA must commit to better enforcement of these measures.”

“… we are deeply concerned that the proposed variance is failing to protect a valuable natural resource and is not delivering continued, meaningful progress. As drafted, the Tentative Variance is inadequate as it allows for continued pollution without requiring substantive corrective actions during the variance period… We do not support the Tentative Variance as written… the ultimate goal should be nothing less than complete or functional elimination of the CSO discharges… The current financial analysis is inadequate for determining the economic feasibility of CSO elimination… Combined Sewer Overflow is an Environmental Justice issue. Environmental Justice (EJ) is a stated priority for the federal government and the Healey-Driscoll administration.”

Dr. Indrani Ghosh’s work to include Climate Change projections in the novel Future CSO Typical …

At the MWRA’s Wastewater Advisory Committee’s meeting on May 12, 2023, the MWRA presented the …

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Dated April 14th, 2023 Joint Press Release APRIL 2023 Alewife Brook/Upper Mystic Combined Sewer Overflow …

Alewife Brook Hydraulic Study for Climate Resilience and Flood Mitigation in Arlington, Belmont, Cambridge, and …

Please Support H.886: An Act Relative to Combined Sewer Overflows Filed by Representatives Adrian Madaro …

An Act relative to combined sewer overflows. Be it enacted by the Senate and House …

This is the Massachusetts Water Resources Authority map from 2016, which we believe has not …

“The overall goal of this feasibility study is to estimate the potential benefits of operating …

The “Alewife Brook 2004 Through 2021 Calendar Year and Typical Year Hydraulic Model Results vs …

This progress report provides a summary of the information presented to and gathered by the …

Development of Future Typical Year of Rainfall Technical Information in Support of the December 15th …

November 21, 2022 letter from Save the Alewife Brook to MassDEP. It is in response …

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The 2019 Alewife Brook CSO Variances (permits to pollute through sewage pollution discharges) expire on …

Download the instruction set for making your own Alewife Brook GHOST FISH! By David …

This is the EPA’s May 11, 2022, guidance for MWRA, regarding their new CSO control …

Sediment Quality of Lakes, Rivers, and Estuaries in the Mystic River Basin, Eastern Massachusetts, 2001–03 …

The Massachusetts Division of Water Pollution Control carried out a limited program of sediment sampling to ascertain the viability of dredging as a short term solution to pollution and flooding problems in the Alewife Brook. No dredging ever occurred but the data from the study remains. Five representative sites along the Little River/Alewife Brook were chosen for sampling and every sample showed some form of contamination.

Hi Folks, Here is part of the 2003 Alewife Masterplan which we will be discussing …

This is the EPA’s guidance for Cambridge, regarding their new CSO control plan “draft …

This is the EPA’s response to Somerville’s new CSO control plan “draft …

Three entities – the City of Cambridge, the City of Somerville and the Massachusetts Water Resources Authority (MWRA) have submitted draft scopes to the federal Environmental Protection Agency and to the state Department of Environmental Protection for the development of a new Long Term Control Plan (LTCP) for the Combined Sewer Overflows (CSO) in the Mystic and Charles Rivers watersheds. Missing from these three scopes is a regional approach which will address the under-represented Environmental Justice Populations who will be most affected by the outcome of the new CSO Control Plan. These include residents who receive the Alewife’s hazardous flood waters in their homes, yards, and parks during flood events. Documented adverse health effects from unavoidable contact with contaminated Alewife flood waters have included, but were not limited to: severe abdominal cramping, bloody diarrhea, headaches, nausea, and vomiting.
The Alewife Basin is densely populated, with 5,000 people living in the Alewife’s 100-year flood plain. Due to the flood-prone topography of the Alewife Basin, when flooding occurs, the flood water can remain for days before receding and flowing out to the Boston Harbor via the Mystic River.
During major flood events, the water level in the Mystic River can rise, causing the Alewife Brook to reverse direction and send hazardous untreated sewage from Belmont, Cambridge, and Somerville into East Arlington, Belmont, and North Cambridge neighborhoods.
Save the Alewife Brook presents its own CSO Control Draft Scope to better represent the humans and other species whose health and well-being are directly impacted by the hazardous risks of untreated sewage discharge in the Alewife Brook.

This map is provided by …

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P. 35 “PURIFICATION OF MYSTIC RIVER AND ALEWIFE BROOK. Under the provisions of chapter 445 of the Acts of the year 1904, the State Board of Health was directed to prepare and report to the next General Court a method and plans for purifying Mystic River, Alewife Brook and the adjacent water courses, ponds and drainage areas, with due regard to the purposes indicated in chapter 327 of the Acts of the year 1903, entitled “An Act to authorize the cities of Cambridge and Somerville and the towns of Arlington and Belmont to improve the condition of Alewife Brook, Little River and Wellington Brook ,” and to the plans of the Metropolitan Park Commission for park developments within the said region, and after conference with the commission ap pointed under the above-mentioned act. An appropriation for carrying on this investigation was made under chapter 129 of the Acts of 1905 ; and on April 28, 1906, the following report was submitted to the Legislature : Acting under the provisions of section 2 of chapter 445 of the Acts of the year 1904, and chapter 129 of the Acts of the year 1905, the te Board of Health has examined the Mystic River and Alewife Brook and their drainage areas, and presents herewith a report of its investigations, together with its recommendations for purifying these waters, and preventing further injury to the public health by reason of unsanitary conditions existing in the valleys of these streams.”

P.39 “The main stream of Alewife Brook is badly polluted by the discharge of foul wastes from a tannery, which enter the stream through Tannery Brook, in the neighborhood of Massachusetts Avenue below the main portion of the marshes on that stream. The quantities of liquid wastes from this tannery vary greatly from time to time, but have been found to amount at times to nearly 100,000 gallons per day, while the quantity of putrescible organic matter contained in these wastes amounts to from five to ten times the quan tity of such matter found in ordinary sewage. A glue factory near the upper end of the Alewife Brook water- shed dis charges foul wastes into marshes bordering the stream, badly polluting sev eral pools in the neighborhood of Concord Avenue. The stream also receives considerable pollution from manure piles and other sources. The chief pollution of Alewife Brook is that which is caused by the over flow of sewage from the combined systems of sewers in the city of Cam bridge, at times of rain or when snow is melting rapidly. The water- shed of Alewife Brook is very thoroughly provided with sewers, which are con nected with the Alewife Brook branch of the metropolitan sewerage system. Most of these sewers are constructed upon the separate plan , with the inten tion of excluding rain water ; but in three districts, in Cambridge, the sewers are built upon the combined plan, and take rain water as well as sewage. These sewers were in existence at the time the metropolitan sewer was con structed, and, as in the case of other similar sewers, the metropolitan system was not designed to take all of their flow ; but provision was made for receiving into the Alewife Brook branch all of the sewage flowing in these sewers in dry weather and a portion of the mingled sewage and storm water at times of rain, allowing the remainder above the capacity of the metro politan sewer at such times to overflow into Alewife Brook. Calculations show that the quantity of sewage discharged into Alewife Brook in this way is large enough to cause gross pollution of the stream in dry weather ; and observations during the past year show that the stream is grossly polluted at such times, and very offensive to those living in its neighborhood, especially in the region above Massachusetts Avenue, where the water available for the dilution of the sewage is only that which flows nat urally from the Alewife Brook water- shed. The effect of the pollution diminishes below Massachusetts Avenue, chiefly on account of the dilution by tide water which runs up the stream to this neighborhood. Whatever provision may ultimately be made for the drainage and im provement of the marshes along Alewife Brook and elsewhere in the Mystic River water-shed , there is no doubt, in the opinion of the Board, that the best plan of preventing the further pollution of Alewife Brook by sewage from the combined sewers, which now discharge into that stream, is to sep arate the sewage from the storm water in these combined areas ; since the rain water and ground drainage, if unpolluted by sewage, could be dis charged into local waters without objection , and all of the sewage proper could then be removed from the district in the metropolitan sewers at all times. It is evident, from an examination of the sewers tributary to the Alewife Brook branch of the north metropolitan sewerage system and the records of the quantity of sewage flowing at different times, that some of them are already overcharged at times of wet weather, owing to the entrance of excessive quantities of water at such times, particularly in the spring. This is especially true of the branches from Belmont and Arlington, and, while some relief has been provided by rebuilding some of the sewers in the former town, further relief will soon be necessary. In the case of the Ar lington sewer also an enlargement is likely to be required when sewers are built in the town of Lexington, which has recently been admitted to the district, and the sewage from which must find its way into the metropolitan system through the Arlington sewer, unless a new sewer shall be constructed. Under the conditions prevailing in this valley, it is likely that the pollution of the streams by sewage from other sewers than the combined systems in Cambridge will result, unless some relief shall be provided. Whether this can best be done by enlarging the metropolitan sewers, or preventing the entrance of unnecessary quantities of water from the tributary systems, is a matter for further and immediate investigation.”

P. 708 “that the sewer in North Cambridge which enters Tannery Brook, the sewage from which flows along and enters Alewife Brook, is a menace to the health of the neighborhood , and should be remedied without delay”

March 11, 2022   Via email   Regional Administrator David Cash Environmental Protection Agency, Region …

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This is a cool image of the Tannery Brook, taken from the 1873 …

Dated June 15, 2020. Awesome map of Somerville stormwater, combined system, and sanitary system. Includes: …

This is a very cool and easy-to-read map of Cambridge’s stormwater catchments. It is well …

Massachusetts Water Resources Authority PRESS RELEASE Date: January 6, 2022 Contact: Ria Convery (617) 788-1105, ria.convery@mwra.com …

New England Journal of Public Policy Volume 8 | Issue 2 Article 7 9-23-1992 The …

MWRA CSO Report is Unfair to Alewife’s Environmental Justice Populations On December 30, 2021, the …

Somerville’s top six worst stormwater outfalls discharge into the Alewife …

Stormwater Management Map. Includes: Storm Discharge Points, CSO Outfalls, Stormwater Manholes, Sanitary and Combined Manholes, …

CIVIL ACTION No. 85-0489-RGS UNITED STATES DISTRICT COURT for the DISTRICT OF MASSACHUSETTS UNITED STATES …

Civil Action 83-1614-RGS United States District Court, District of Massachusetts United States v. Metropolitan District …

1904 Metropolitan Parks Commission Report on Alewife Improvements, including tidal gates and channelization of the …

Doug Foy, Esq., director of the Conservation Law Foundation, who brought the groundbreaking Boston Harbor Clean-up lawsuit, probably quoting an ubran sociologist, said, “A great city had three characteristics: It had world-renown cultural and educational institutions. It had enduring distinctive residential neighborhoods, and it had a body of water that it embraced.”

This document outlines the stormwater management practices that are currently in place and ones that …

New projects described here include combined sewer separation, flood control are encouraging. Interesting data about …

2021 Letter from the Charles River Watershed Association and the Mystic River Watershed Association to …

This is the MDC (rebranded as DCR) map of the Arlington and Somerville half of …

Wondering what’s involved in combined sewer separation and CSO elimination work? This is Cambridge’s $90 …

This document provides the MWRA’s 1994 cost estimate and economic analysis for system-wide (not just …

This is the Cambridge half of the MDC (rebranded DCR) 2003 Master Plan Map …

This is a powerpoint presentation by Carter Stantec for the 2017 Massachusetts Coalition for Water …

This is Cambridge’s Alewife Development Planning document from 1979. The MBTA’s Alewife T stop was …

This is Cambridge’s 2019 Alewife Planning and Development document. It includes information about flooding, water …

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