Somerville_City_Council_03132025 — File 25-0510

December 18,2023 DEPARTMENT OF CONSERVATION & RECREATION, SAVE THE ALEWIFE BROOK, & GREEN CAMBRIDGE

Rain that falls in the Alewife Brook subwatershed drains to Alewife Brook. The black line shows the border of the Alewife Brook subwatershed.

In 2023, the brook flooded over its bank at least 5 times, sending untreated sewage flood water into the DCR state park and into the Alewife Greenway Path. The Alewife Greenway Path is a heavily trafficked multi-use path on DCR land. It links Medford, Somerville, Arlington and Cambridge residents to the Alewife Red Line T stop. Somerville residents use this path. Somerville Road Runners on this path. West Somerville neighbors use this path.

In 2023, 29 million gallons of untreated sewage pollution was dumped into Alewife Brook. In 2021, 51 million gallons of untreated sewage was discharged into the brook.

This is a densely populated area, with 5000 people living in the Alewife’s 100-year floodplain. There are multiple environmental justice neighborhoods along the brook. Here is a map of Alewife Brook’s six active CSO outfalls. All Alewife Brook CSOs are untreated.

Somerville has two Combined Sewer Overflow (CSO) Outfalls. Somerville’s Mystic River CSO, SOM007A, discharges treated sewage pollution. Treatment neutralizes harmful bacteria. SOM001A, the Tannery Brook CSO, discharges untreated sewage pollution to Alewife Brook.

Tannery Brook CSO Toilet paper hangs from a branch at SOM001A.

7.02 MG https://www.mwra.com/media/file/2023-cso-annual-report

17.98 MG https://www.mwra.com/media/file/2021-cso-annual-report

What has Somerville done to reduce CSOs in Alewife Brook? Above schedule from Boston Harbor Cleanup Court Case & from the first Long Term CSO Control Plan, completed in 2015.

August 31 2024 MassDEP issues Water Quality Variance for Alewife Brook Thanks to public support and MassDEP’s hard work, the Alewife Brook Water Quality Variance now requires: 1. A Study on Installing Onsite Real-time CSO Notification to protect people from unknowingly walking through sewage flooding. We asked for a red-amber-green light at each CSO and where the Brook floods onto the Greenway path. 2. Odor Control. MWRA, Somerville, and Cambridge shall implement Best Management Practices for odor control for their Alewife sewer systems. 3. “Floatables” Control study for all Alewife CSOs. Somerville must determine how to fix their CSO to screen out or clean up toilet paper and other hazardous human waste products. 4. Fair and Just Financial Capability Analysis to make improvements at the local level. Massachusetts Water Resources Authority will not get away with submitting their “system-wide elimination” cost of billions of dollars. They don’t need to separate every sewer pipe throughout Boston to solve the problem for Alewife Brook. There are viable solutions for the Alewife and MWRA knows it! 5. Acknowledgement of Climate Change. Incorporation of Climate Change Impacts in planning, with future storm event reporting to be based on updated rainfall data from the latest NOAA Atlas . 6. Green Infrastructure must be considered by Somerville, MWRA, and Cambridge.