In 1984, as a result of the Boston Harbor cleanup court case, the Legislature created the Massachusetts Water Resources Authority to tackle the region’s greatest environmental crisis – sewage pollution, sewer infrastructure failures and decades of mismanagement. Under the glare of the national spotlight during the Bush vs. Dukakis presidential campaign, and with the legal muscle of the Conservation Law Foundation and Environmental Protection Agency in federal and state courts, the Legislature empowered MWRA with a dedicated funding mechanism for infrastructure upgrades.
The authority’s Enabling Act of 19841MWRA Enabling Act, Chapter 372 of the Acts of 1984 mandates the “repair, replacement, rehabilitation, modernization and extension” of the sewer system “in the best interests of the commonwealth and its inhabitants, to promote the general health and welfare, to improve commerce and living conditions of the citizenry.”
Through borrowing backed by water and sewer system revenues, with rate increases throughout the 1980s and ’90s2Paul Levy’s Financing the Boston Harbor Project, the authority raised $5 billion, funding the construction of the Deer Island Treatment Plant and reducing combined sewer overflows. The result has been a $100 billion return in public health, environmental recovery and real estate value. This is the story of one of the Clean Water Act’s greatest environmental successes in the United States.
CSOs are a regional problem of a connected sewer system
The authority owns aging sewer system infrastructure that ties Cambridge and Somerville to its regional system at Alewife Brook, including two large “interceptor” pipes built in 1896 and 1948. Those interceptors are connected to all six Alewife Brook combined sewer overflow outfalls, as well as the Alewife Brook Pump Station. The Alewife Brook Pump Station is the oldest operating pump station in the MWRA system.
Stormwater in the combined systems regularly overload the sewer system during wet weather storm events – sometimes when the area gets less than an inch of hard rain. At a Feb. 22, 2022, public briefing to discuss the Final Combined Sewer Overflow Performance Report, the authority’s consultant from Aecom explained that the system is limited by downstream capacity and “under very large storm events,” the Alewife Brook Pump Station reaches capacity despite being a “very large facility” capable of handling 90 million gallons per day. “That then discharges into sewers conveying flow further downstream and going to the Chelsea Creek Headworks, that then reaches capacity. And there are events when the capacity of our Deer Island treatment plant, 1.2 billion or 1.3 billion gallons per day, is reached. So there are limits to what the MWRA can push through the system.”
The regional sewer system simply cannot move the stormwater in the system during many storms. Raw sewage mixed with stormwater from Cambridge and Somerville discharges into Alewife Brook because it has nowhere else to go.
Open sewers are part of MWRA’s strategy
The authority’s 2018 Wastewater Masterplan states that combined sewer overflows provide “additional system capacity”.3MWRA’s 2018 Wastewater Masterplan, Page 9: “The Deer Island Treatment Plant receives an average daily flow of 353 mgd and has a peak wet weather capacity of 1,270 mgd, with additional system capacity available at combined sewer overflow outfalls.” For the authority, combined sewer overflows are a feature of its system that is overburdened by an increasing amount of stormwater from increasing amounts of precipitation due to climate change. With six active raw combined sewer overflow outfalls at Alewife Brook, the authority, Cambridge and Somerville use Alewife Brook as an open sewer.
MWRA’s annual revenue
The authority’s budget this year is $922 million, and 95 percent of its revenue comes from ratepayer money – that includes more than a million households and businesses paying water and sewer bills to their municipalities.
The authority uses its revenue to back long-term bonds to pay for sewer system upgrades at more favorable interest rates than cities, Massachusetts or even the federal government. Decades ago, the authority issued billions of dollars in bonds to pay for the Harbor Cleanup combined sewer overflow projects and Deer Island treatment plant. Those bonds are now expiring, meaning they are paid off. In the next 10 years, the authority has the capacity to issue another $2.1 billion in bonds4MWRA Annual Report November 2024, Secured Bond Debt Service chart, Page 2.. The authority’s revenue remains the same, steadily increasing by 3 percent to 4 percent annually, so the budget already exists for the debt service on new bonds. Thus, there will be no huge shock to the ratepayers on their sewer bills.
MWRA’s legal and financial responsibility
According to the Boston Harbor Court Case’s second stipulation5Exhibit B, paragraph 4 of the second stipulation, MWRA “accepts legal liability to undertake such corrective action as may be necessary to implement the CSO control requirements set forth in Schedule Six and related orders of the Court… and to meet the levels of CSO control.”, the authority is legally and financially responsible for combined sewer overflows that are in violation of the Boston Harbor court case.
As of this year, six untreated combined sewer overflows outfalls remain in violation of the court order6MWRA’s Dec. 27, 2024, supplement to the 2021 Final Combined Sewer Overflow Post Construction Monitory Program and Performance Assessment Report, Section 4 Update to the Final Assessment Report – Summary and Conclusions., as they do not meet the required levels of control mandated by the court. These are discharges of untreated sewage, making them considerably more hazardous to community health than treated CSOs.
Other outfalls in the authority system are not in compliance with the court order, but are expected to meet the court order by the end of this year. That includes Somerville’s treated CSOs at Mystic River.
According to the court’s second stipulation, the MWRA is responsible for funding infrastructure work on these outfalls. Using the authority to pay for as much of these plans as possible lowers the cost and accurately reflects the regional nature of these challenges. Some costs may fall on the cities as well. For example, the cities may have additional costs related to complete streets and stormwater infrastructure when doing sewer separation work.
The authority should cover costs for all legally required work. Additionally, the Legislature should seriously consider expanding the scope of the authority through updated enabling legislation. Stormwater is an unavoidable part of solving CSOs and managing our regional water infrastructure more generally.
The authority’s February financial analysis7Feb. 4 MWRA board meeting materials, page 27: “The sewer system annual household charges are currently anticipated to increase from $999 per year to $2,337 per year without the CSO spending between fiscal years 2029 and 2050. In 2050 based on the additional CSO spending, the household charges are projected to increase to $2,380, $2,433 and $2,462 per year for spending associated with level of control to achieve zero CSOs in the 2050 typical year, 2050 5-year and 2050 25-year storms, respectively.” shows that the difference in household sewer bills between the least and most expensive plans – which would virtually8The 2050 25-Year Storm level of control is the equivalent of CSO elimination. It is the Watershed Associations’ recommended level of control. eliminate sewage pollution in the Charles, Mystic and Alewife – is minimal, roughly the cost of a cup of coffee per month.
The difference in cost annually to households between the bare minimum CSO plan and the most expensive is $82 in 2050. That is equal to $46 in 2025 dollars, using the authority’s assumed rate of inflation at 2.5 percent.
MWRA’s senseless demand of “cost sharing” with Cambridge and Somerville
In meeting materials from a Feb. 25 authority board of directors meeting9MWRA board of directors meeting materials from Feb. 25, a staff note from MWRA executive director Fred Laskey proposes that Cambridge and Somerville pay a total of $516 million for combined sewer overflow control plans, which includes Alewife Brook and the Charles and Mystic rivers.
According to the court case’s second stipulation10Exhibit B, paragraph 4, of the second stipulation, MWRA “accepts legal liability to undertake such corrective action as may be necessary to implement the CSO control requirements set forth in Schedule Six and related orders of the Court … and to meet the levels of CSO control.”, though, the cities do not have to contribute funding toward projects involving the two Alewife combined sewer overflow outfalls that are in violation of the court at the MBTA’s Alewife Station and Davis Square Tannery Brook.
The cities are not responsible for the cost. MWRA has asked Boston to pay nothing, which is correct because Boston has been aggressively preparing for climate change with sewer separation in East Boston. But Cambridge and Somerville have been aggressively investing in sewer separation too. As a regional entity, the authority should pay for regional solutions. It is legally responsible for paying for infrastructure upgrades associated with the combined sewer overflows that are in violation of the court order. The authority needs to begin investing now in removing stormwater from its regional sewer system, in preparation for Climate Change.
Now is the last time that Cambridge and Somerville are able to use MWRA funding, as required by the Harbor court case, to cover the cost of sewer infrastructure upgrades. It is in the region’s interest to remove stormwater from the combined systems now through sewer separation. The cities should push for the most ambitious plan to modernize their 19th century sewer systems now. To do otherwise would be fiscally irresponsible. It will never be cheaper to do this work than it is now. Climate change demands an investment in sewer separation and green stormwater infrastructure now.
A version of this post appeared on the website of Save the Alewife Brook, a community health advocacy group.
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