Notice Alert: CSO Activation in Alewife Brook

TO: Jenny Birnbaum, Mystic Monitoring Network Director, Mystic River Watershed Association
Sam Lipson, Director, Environmental Health Unit, Cambridge Dept. of Public Health
Elizabeth Quaratiello, Director, Somerville Health Department
Christine Connolly, Director, Arlington Department of Public Health
Donna Moultrup, Director, Belmont Department of Public Health
Richard Chretien, Department of Environmental Protection
Kevin Brander, Department of Environmental Protection
Todd Borci, United States Environmental Protection Agency
William Walsh-Rogalski, United States Environmental Protection Agency

FROM: Catherine Daly Woodbury, Cambridge DPW

CC: Massachusetts Water Resource Authority Ria Convery, Grace Vitale
City of Somerville Engineering Charles O'Brien, Environmental Coordinator Vithal Deshpande
Town of Arlington Department of Public Works John Sanchez, Director
Town of Belmont Department of Community Development Glenn Clancy, Director
Friends of Alewife Reservation Ellen Mass
City of Cambridge Department of Public Works Owen O'Riordan, James Wilcox, Rebecca Fuentes,

RE: Notice Alert: CSO Activation in Alewife Brook

DATE: February 1, 2008

In accordance with the conditions of the Department of Environmental Protection's (DEP) Alewife Brook/Upper Mystic River Variance we are hereby notifying you that a Combined Sewer Overflow (CSO) occurred at CAM401B on February 1, 2008 and discharged into the Alewife Brook. The Variance approved workplan requires the Cambridge Department of Public Works (DPW) to notify local health agents, DEP, EPA and MRWA within 24 hours of when a CSO event occurs. It was determined that 401B was the most active outfall and would be the most suitable indicator of CSO activity along the Alewife Brook. This notification does not reflect the absence of any activation at other sites. Rather, the notice is intended to be confirmation to users of the resource that untreated sewage discharges to the Brook/River have 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 Cambridge and Somerville are served by combined stormwater and sanitary sewer systems, common in older cities. There are eight CSO outfalls on Alewife Brook (see the attached map for locations) which discharge untreated CSO (a mixture of wastewater and stormwater) during moderate and heavy rainfall to 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 and for 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. A Storm Fact Sheet is available on the MA Department of Environmental Protection web site at http://www.mass.gov/dep/brp/stormwtr/files/flooding.htm. In addition, you can consult the Mystic River Watershed Real -Time Water Quality Monitoring Site located at http://www.mysticriveronline.org. This web site is designed to collect remote data every 15 minutes and water quality samples daily within the Mystic River Watershed. The site is sponsored by the City of Somerville, EPA, Tufts University and the Mystic River Watershed Association. Contact Catherine Daly Woodbury at 617-349-4818 or James Wilcox at 617-349-6426 if you have any questions.

CSO Outfalls along the Little River/Alewife Brook