City of Cambridge November 25th sewage discharge in Little River and Alewife Brook

Combined Sewer Overflow (CSO) Event on 25 November 2018 at 7:10 AM at SOM001A on the Alewife Brook

In accordance with the conditions of the Department of Environmental Protection's (DEP) Alewife Brook/Upper Mystic River Variance we are hereby providing public notice that a Combined Sewer Overflow (CSO) occurred at SOM001A and discharged into the Alewife Brook. The Variance approved workplan requires the Somerville Department of Public Works (DPW) to notify local health agents, the DEP, the EPA and the MRWA within 24 hours of a CSO event. The notice is intended to confirm to users of the resource that untreated sewage discharges to the Brook/River has occurred.

The water quality in Alewife Brook is often impaired due to bacterial and other pollutants from a number of sources, including stormwater runoff, CSOs and cross connections between sanitary sewers and stormwater drains. Water quality in the Brook during both wet and dry weather generally fails to meet state bacteria standards for fishing and swimming. Contaminant sources originate in the watershed communities of Belmont, Arlington, Cambridge and Somerville, all of which are undertaking programs to identify and control the sources of pollution to the brook.

Portions of Somerville are served by combined stormwater and sanitary sewer systems, common in older cities. The CSO outfalls on Alewife Brook (see the attached map for location) which discharge untreated CSO (a mixture of wastewater and stormwater) during moderate and heavy rainfall relieve the system and prevent sewer backups into homes, businesses, and streets. In addition, bordering communities also have separate drainage pipes that collect stormwater runoff and carry it to the brook. Discharges from CSOs and from separate stormwater pipes include bacteria and other pathogens, oxygen-demanding pollutants, solids and other contaminants. Public health officials recommend avoiding contact with the Brook during storm events and for a period of 48 hours following rain storms, as there may be increased health risks during these periods. Contact with floodwaters should also be avoided as they may contain similar contaminants and pose associated health risks. Clean up information following a flood is available on the MA Department of Environmental Protection website at this link. For real-time water data at Fresh Pond Reservoir, you can view the United States Geological Survey National Water System website at: http://waterdata.usgs.gov/ma/nwis.

For additional information on the Somerville system, you may contact the Engineering Department at 617.625.6600 ext.5400.

You can check out a list of recent CSO events in Little River and Alewife Brookhere.