CAMBRIDGE – Throughout the summer, volunteers from ShoreRivers collect water samples every week at local swimming areas and post the results, showing whether they meet, or don't meet the Environmental Protection Agency’s recreational water-quality standard.
The most recent results are:
Bacteria levels can change, particularly as a result of significant rain events, and so it's advised that swimmers stay out of the water for up to 24-48 hours after a significant rain event, as defined as greater than 1" of rain within a 24-hour period.
Persons should never swim in the river with open wounds or cuts, and should always wash after swimming. There are inherent risks associated with open water swimming beyond high bacteria levels, such as harmful algal blooms, vibrio, rough conditions and drowning hazards. Swimmers and beachgoers should be advised to obey signs and laws wherever they plan to recreate in the water.
Download the "Swim Guide" App. for your phone theswimguide.org/get-the-app.
The Swimmable ShoreRivers program uses the standardized EPA criteria for recreational swimming of 104 Colony Forming Units (CFU)/100ml for analyzing a single bacteria sample. Anything higher than 104CFU is a failing sample, and anything below 104CFU is a passing sample.
Not all test sites are designated swimming areas.