On August 8th, 2024, Save the Alewife Brook provided an “Alewife Brook CSO*s 101” class and walking tour to students participating in the local Biodiversity Builders program. We explained the basics and some of the details of Alewife Brook’s Combined Sewer Overflows**. Our course materials are available for download below.
Biodiversity Builders is an environmental education initiative that provides paid summer internships to high school students in the area. The program, organized by Jean Devine of Belmont, educates students on restoring local ecosystems through native plantings and promotes advocacy for nature-based solutions to combat Climate Change.
Biodiversity Builders students and members of Save the Alewife Brook next to Cambridge’s worst CSO: CAM401A.
Do you live in the Alewife Brook Watershed?
Our CSOs 101 class began at the Alewife Showcase Pollinator Garden , where we presented the Mystic River Watershed Association’s map of the Alewife Brook Watershed. Rain that falls within the black-bordered outline on the map drains to Alewife Brook. Interestingly, all students in the class live within the Alewife Brook Watershed – some students live in Cambridge, others in Belmont, and some in Arlington.
The students learned that untreated sewage in Alewife Brook is particularly alarming because the Brook floods regularly. Last year, it flooded multiple times, sending untreated sewage flood water into our State park and into Environmental Justice neighborhoods. Unaware of the sewage discharges, neighbors continued to jog, cycle, and push baby strollers through contaminated sewage floodwater.
Next, we toured the Commonwealth’s CSO, MWR003, and discussed how it was reconstructed in 2015 to discharge larger volumes of untreated sewage than it had before. This CSO functions as cheap hydraulic relief for the Commonwealth’s downstream sewer system which has systemic problems and lacks adequate capacity during storm events.
We also visited CAM401A, Cambridge’s worst CSO, located next to the MBTA’s Alewife Station parking garage. In 2023, this CSO discharged over 20 million gallons of sewage pollution. The 2023 discharge from CAM401A significantly exceeded the permitted annual total for all the Alewife Brook CSOs of 7.3 million gallons.
Finally, we discussed both immediate and long-term achievable solutions to the problem. The class concluded with a walk through Cambridge’s beautiful Alewife Stormwater Wetlands. This engineered wetlands is a large green stormwater infrastructure project that was part of the first CSO control project that was completed a decade ago. It serves to mitigate flooding by storing stormwater and enhancing water quality of what eventually flows into Alewife Brook. The students enjoyed identifying native plantings and wildlife there.
Download our CSOs 101 Course Materials here:
MyRWA’s Alewife Watershed Map
EPA’s Combined Sewer Overflow Basics
Alewife Sewage Pollution Flooding
Better Know a CSO: A Tour of the Alewife Brook Combined Sewer Outfalls
We would love to present our Alewife CSOs 101 Class to your students, of any age.
Please feel free to get in touch with us about our free classes by emailing us here.
* CSO = Combined Sewer Overflow, where the overflow from combined storm and sanitary sewers discharge sewage (human and industrial wastes) into public waters.
** Six CSOs dump untreated wastewaters into Alewife Brook. One is from Somerville, one is from the Massachusetts Water Resources Authority, and four are from Cambridge.