EXECUTIVE SUMMARY
By April 30, 2026, the Massachusetts Water Resources Authority (MWRA), Cambridge, and Somerville are required to submit a single draft Combined Sewer Overflow (CSO) long term control plan for the Charles & Mystic Rivers and for Alewife Brook to the Massachusetts Department of Environmental Protection (MassDEP). Because of community health and environmental impacts of CSOs, any plan for Alewife Brook must end CSO sewage pollution while reducing area flooding and improving water quality.
This Community Plan leans on the Principles and Goals[1] outlined by the Coalition to End Sewage Pollution[2], while being mindful of cost, technical feasibility, and project completion time.
- The plan calls for modernizing the Victorian-era sewer systems of Cambridge and Somerville by creating separate storm and sanitary sewers in the Alewife Brook basin, as has been accomplished in parts of Cambridge and Somerville already.
- It calls for more Green Stormwater Infrastructure, including constructed stormwater wetlands in the Alewife area, in locations already identified by the Department of Conservation and Recreation’s master plan for the Alewife Reservation, and for an underground holding tank at the Alewife Station area for MWRA combined sewage, as MWRA has already proposed in its draft plans.
- Our plan is achievable at a reasonable cost. It is resilient to Climate Change, as it has the added benefit of reducing stormwater flows to the MWRA sewer system in storms when the system would otherwise be over capacity. And it would provide for green infrastructure to improve neighborhoods.
- The Community Plan calls for dredging and restoration of Alewife Brook. The Brook has become degraded by decades of sediment accumulation caused in large measure by the CSOs and stormwater inputs
[1] The Coalition to End Sewage Pollution: Share Principles & Project Goals: https://savethealewifebrook.org/wp-content/uploads/2025/10/Coalition-to-End-Sewage-Pollution-Shared-Principles-and-Shared-Goals-2025.pdf
[2] Coalition to End Sewage Pollution Announcement: https://savethealewifebrook.org/2025/11/08/the-coalition-to-end-sewage-pollution/