January 13, 2024

Avoid Contact with the Alewife Brook in Cambridge Due to Potentially Harmful Bacteria and Other Pollutants Until January 15, 2024

Public Warning in effect until January 15, 2024

People and pets should avoid contact with the Alewife Brook from January 13-15 due to the release of stormwater mixed with sewage into the brook.

The release of mixed stormwater and sewage—known as a “combined sewer overflow (CSO)”—is needed to prevent contaminated water from backing up into homes, businesses and city streets. An SSO is an unintentional discharge of wastewater to the environment prior to reaching a treatment facility. SSOs occur infrequently, when the capacity of the sewer system is exceeded—usually due to extreme conditions such as heavy rainfall or an obstruction or break in sewer lines.

State regulations require local public health departments to provide notice to the public when these discharges may create a risk to public health, including when a discharge lasts for more than two hours. For information about discharges that lasted less than two hours in the Cambridge area, please visit Cambridge Department of Public Works, City of Somerville, and Massachusetts Water Resources Authority’s websites.

One CSO release occurred in/near Cambridge on Saturday morning, January 13 that lasted more than two hours. This CSO release was in the Little River/Alewife Brook:

  • CAM401A beginning at 5:06 a.m. and ending at 8:46 a.m. CAM401A is located upstream of the confluence with the Little River and upstream of the Route 2 Bridge.

This warning is in effect until 8:46 a.m., Monday, January 15, 2024. Impacted areas may include Arlington, Cambridge, Somerville, and Medford.

The public should avoid contact with impacted areas of the river for 48 hours from the time the overflow ends because of increased health risks due to bacteria or other pollutants carried by the stormwater, such as fertilizers or pesticides. Contact with this water can make you and your pets sick. Avoid paddle boarding, boating, fishing, or other activities that can bring you in close contact with this water. 

Information about Cambridge CSO events are posted on the Cambridge Department of Public Works website.  Additional information is available on the Massachusetts Water Resources Authority and City of Somerville’s websites. Translations of the web pages are available using the translate box along the top of the websites.

The City of Cambridge continues to make major improvements to the city’s sewer and stormwater systems.  As a result, there are fewer CSO events than in the past, but they still occur after heavy rain.  To learn more, please visit: www.cambridgema.gov/csoPlanning

The state law requiring public notification of sewage discharges into waterways took effect in 2022. Environmental groups advocated for the law because they were concerned that Massachusetts had no system in place to alert residents when sewage discharges occurred and what people could do to avoid illness. The new law requires municipalities to alert residents in multiple ways when discharges occur and to make the information available in other languages.

If you have questions about potential health risks from contaminated water, contact Sam Lipson at the Cambridge Public Health Department at [email protected] or 617-665-3838.

Translated Information

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ለበለጠ መረጃ፣ እባክዎን ድህረ ገጾቹን ይጎብኙ። በቀኝ በኩል በላይኛው ጥግ ላይ ያለውን “Translate” የሚለውን ሳጥን ይፈልጉ እና ቋንቋዎን ይምረጡ



Haitian Kreyòl 

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