Progress Toward A Swimmable Charles River: CRWA Applauds MWRA, Cambridge And Somerville For Presenting Options To Eliminate Sewage Overflows (Press Release)
FOR IMMEDIATE RELEASE: January 23, 2025
Contact: Stefan Geller
Phone: 617-540-5650 X 1094
Email: sgeller@crwa.org
BOSTON, MA – Last night, the Massachusetts Water Resources Authority (MWRA) and the cities of Cambridge and Somerville introduced several alternative project concepts to eliminate Combined Sewer Overflows (CSOs) from polluting the Charles River, a significant step toward delivering the swimmable river promised by the 1972 Clean Water Act.
MWRA, Cambridge, and Somerville are required to carry out an extensive updated CSO planning effort to address the ongoing challenge of raw and partially treated sewage being dumped into the Charles River during heavy rain.
CSOs are a key source of contamination to the Charles and are becoming more frequent as our climate changes. In these outdated systems, stormwater and household/industrial wastewater are collected in the same pipes to be conveyed to a wastewater treatment plant, but during heavy rainstorms, the combined system cannot handle the excess polluted water and releases it into the river.
One option MWRA, Cambridge, and Somerville presented was a CSO storage tunnel, a well-established technique to eliminate combined sewage discharges that has been used in Portland (OR), Milwaukee, and South Boston. This innovative tunnel would be designed with climate change in mind, making CSOs a thing of the past in all but the most severe storms expected under future climate conditions.
Additional options presented include implementing green stormwater infrastructure (GSI) in combination with tunnel storage to reduce or eliminate CSOs in smaller storms. GSI provides numerous co-benefits, such as reducing flooding and urban heat impacts, improving air and water quality, and beautifying neighborhoods.
“This investment will pay dividends for future generations as climate change increases the imperative for access to public swimming areas, making good on the promises of the 1972 Clean Water Act and the Clean Charles Initiative of 2005,” said Max Rome, CRWA’s senior stormwater program manager.
“For the past decade, we’ve seen little to no improvements to CSO conditions in the Charles River, and overflows vary year to year based on the weather. So it’s exciting to see real projects that could make meaningful improvements,” said Julie Wood, CRWA’s climate resilience director. “Now we need to get this done. With this once-in-a-generation investment, we can stop the flow of untreated sewage into our environment while also greening and beautifying our neighborhoods.”
“We are pleased to see these project ideas from MWRA, Cambridge, and Somerville, which is a key step in the path to a Charles River clean enough to swim in,” said Emily Norton, executive director of CRWA. “Imagine during our hotter summers, if greater Boston residents of any income level would have a safe, free place to jump in the water to cool off. We look forward to working with MWRA and the cities of Cambridge and Somerville to make that vision a reality.”
While the MWRA has reduced sewage discharges by over 95% since 1988, tens of millions of gallons of sewage-laden stormwater are still entering the river every year, and that volume is growing thanks to climate change. In 2023, 72 million gallons polluted the Charles, equivalent to 109 Olympic-sized swimming pools.
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Charles River Watershed Association’s mission is to protect, restore, and enhance the Charles River and its watershed through science, advocacy, and the law. CRWA develops science-based strategies to increase resilience, protect public health, and promote environmental equity as we confront a changing climate.
