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Avoid contact with the Alewife Brook and Charles River in Cambridge until June 1. 2024

Public Health Warning in effect until June 1, 2024

People and pets should avoid contact with the Alewife Brook and parts of the Mystic River and the lower Charles River from May 30-June 1 due to the release of stormwater mixed with sewage into the brook and rivers.

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.

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 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.

Two CSO releases occurred in/near Cambridge on Thursday morning, May 30 that lasted more than two hours.

One CSO release occurred on May 30, 2024 in the Little River/Alewife Brook from CAM401A. CAM401A is located upstream of the confluence with the Little River and upstream of the Route 2 Bridge. It began at 8:27 a.m. and ended at 10:57 a.m.

Impacted areas may include Arlington, Cambridge, Somerville, and Medford.

One CSO release occurred on May 30, 2024 between Magazine Park and the Boston University Bridge (MWR201 – Cottage Farm). MWR201 is located at Magazine Beach. It began at 10:13 a.m. and ended at 12:18 p.m.

The impacted areas of the Charles River may include the Cambridge and Boston sides of the river just upstream of the Boston University Bridge to the Mass. Ave. Bridge.

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 slipson@challiance.org or 617-665-3838.

Translated Information

For more information, please visit these websites. Find the “Translate” box at the top corner on the right and select your language.


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


Haitian Kreyòl

Pou plis enfòmasyon, tanpri vizite sit entènèt sa yo. Jwenn bwat “Translate” nan kwen anwo dwat epi chwazi lang ou.



Para mais informações, visite esses sites. Encontre a caixa “Translate” no canto superior à direita e selecione seu idioma.



Para obtener más información, visite los sitios web. Busque el cuadro “Translate” en la esquina derecha superior y seleccione su idioma.


Page was posted on 5/31/2024 11:12 AM
Page was last modified on 5/31/2024 11:13 AM
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