Combined Sewer Overflow to Alewife Brook

Combined Sewer Overflow to Alewife Brook

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 July 28, 2014 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. Clean

up information following a flood is available on the MA Department

of Environmental Protection web site at:

http://www.mass.gov/dep/floodcleanup.htm

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

Please contact Catherine Daly Woodbury at 617-349-4818 or James

Wilcox at 617-349-6426 if you have any questions.