Toxic bacteria closes Chebacco Lake

PAUL BILODEAU/Staff photo. Chebacco Lake at Centennial Grove, pictured here, is closed to swimming due to a bloom of toxic algae. 7/26/20

A Gloucester beach has reopened while an Essex one remains closed after officials banned swimming at them this weekend.

Gloucester's downtown beach, Pavilion Beach off Western Boulevard, was closed to swimming Friday and reopened Sunday.

Meanwhile Chebacco Lake at Centennial Grove in Essex is closed because of high levels of toxic bacteria.

Gloucester officials closed Pavilion Beach out of an abundance of caution after Thursday's heavy rains and flash flooding surging through the stormwater system overflowed into the harbor.

The city tested the water for high bacteria levels on Friday morning, and reopened the beach Sunday after testing showed safe levels. Testing is administered by the state Bureau of Environmental Health and the state limit for safe swimming is 35 bacterial colony-forming units per 100 milliliters of water.

Chebacco Lake was closed Friday after a bloom of toxic algae was found.

"We have received confirmation from the Massachusetts Department of Public Health's Environmental Toxicology Program that there is a harmful algal bloom (HAB) of cyanobacteria in Chebacco Lake," said the Essex Board of Health‎ on Facebook, adding the sample was taken Thursday. 

YMCA Camp Dory uses the lake weekdays for activities. "The camp director has been notified and swimming activities are canceled for the time being," the Essex Board of Health said.

Health concerns associated with cyanobacteria blooms vary depending on the type of cyanobacteria, the route of exposure, and the amount of cyanotoxins present, the health board said. The bloom makes the water unsafe and the state and local health board advise that people and pets:

Keep away from the lake.

Do not swim. Inhaling water spray containing cyanobacteria can cause asthma-like symptoms. Small children and pets are more susceptible to the effects of cyanotoxins than adults.

Do not swallow water. Ingestion is the primary concern since ingesting small amounts of cyanobacteria or cyanotoxin can cause gastrointestinal symptoms while larger amounts may cause liver or neurological damage. 

Rinse off after any contact with the water. Contact with cyanobacteria can cause skin or eye irritation.

The Essex Board of Health is still in the process of identifying the type of cyanobacteria observed at Chebacco Lake. Updates will be posted on the Board of Health page at

Updates on Gloucester's beaches are posted on the Gloucester Beaches Facebook page.

Andrea Holbrook may be contacted at 978-675-2713 or





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