Last October, the Massachusetts Water Resources Authority (MWRA) introduced a proposal to reclassify the Charles River as a “Class-B (CSO)” water body. This change would have allowed Combined Sewer Overflows (CSOs) to continue discharging into the river indefinitely and removed Cambridge’s legal obligation to eliminate sewage pollution.
Following public outcry, an alternative plan was introduced on February 4 and approved by the MWRA board on February 25. While the revised plan avoids reclassification, it still permits ongoing sewage discharges into the river. The plan is expected to be released to the public by the end of April and will take effect in January 2027 if approved by the Massachusetts Department of Environmental Protection (MassDEP).
Students who use the river for athletics say these conditions are already affecting them. Sarah Baker ’28 is among the rowers impacted by water quality issues.
“About four days before Head of the Charles, I was selected to row the U17 boat, and then suddenly, after practice one day, I got really sick,” she said. “I was throwing up, and I couldn’t come to school for several days. I couldn’t row, and I was afraid I was going to lose my seat in the boat. It was after we rowed down to the Harvard Bridge, which is where the cyanobacteria blooms were the most serious, and my symptoms were on par with that, so that’s what I figured it was.”
Cyanobacteria blooms in the Charles River are associated with excess nutrients in sewage released during overflow events and can pose health risks.
Arrianna Prioa, Senior Community Organizer at the Charles River Watershed Association (CRWA), said the issue extends beyond a single river.
“This is not just unique to the Charles River. This is, unfortunately, an issue that affects rivers across the state. There are real environmental impacts and public health concerns. CSOs can carry bacteria, viruses, pharmaceuticals and trash, making contact with the water unsafe for 48 hours after a discharge and rendering the river very inaccessible,” she said.
Boston’s combined sewer system is outdated, making it unable to handle the stormwater produced by large storms, Arrianna said. When these storms occur, untreated or partially treated sewage from wastewater pipes combines with runoff from storm drains and floods into the same pipes that lead to the Charles River.
“Climate change is causing more intense storms, so we’re just seeing more and more sewage discharges.”
EcoReps member Tess Lessig ’28 said the proposal could negatively affect those who use the river.
“As a sustainability advocate, looking at the welfare of the people around it, I would say the plan most negatively impacts inhabitants around the river,” she said. “I definitely don’t think it should be passed.”
The CRWA estimates it could cost taxpayers about $46 per household annually to better control CSOs. The MWRA has cited cost as a major factor in its decision.
Cambridge resident and Head of the Charles alternate Julia Agudelo ’28 said it is worth the price.
“The affordability comes at a cost of the environment being less protected as well as the rowers that are out on the river every day,” she said. “We’re so fortunate to live in a city that has so much tax money coming into it and funding it and fixing the parks, and this is a relatively wealthy city, it’s crazy.”
Girls’ Varsity Crew member Caroline Killory ’27 said she was surprised by the lack of awareness surrounding the issue.
“As someone who spends a lot of time on the river, that’s really disgusting,” she said. “There’s not as much publicity as there should be to warn people. People don’t really know about the sewage.”
