Bacteria bloom raises concern at Elm Brook Park Beach in Hopkinton

Monitor staff
Wednesday, June 13, 2018

Boaters and swimmers at Elm Brook Park Beach in Hopkinton are being cautioned about a bloom of cyanobacteria that is clouding the water and might produce health concerns.

The advisory, released Tuesday by the New Hampshire Department of Environmental Services, says people and pets should “avoid contact with the water … where lake water has a surface scum, green streaks or blue-green flecks aggregating along the shore.”

Keeping pets away is important; dogs can be sickened if they drink water that has blooms of the bacteria, often inaccurately called blue-green algae.

Samples were collected by the Army Corp of Engineers revealed that the state threshold of 70,000 cells per milliliter of cyanobacteria was exceeded. The bloom was described to be dense and stretched at least 1,000 feet around the beach.

This warning is not based on a toxin evaluation, however, and is being called “a precautionary measure for short-term exposure.”

Once a cyanobacteria lake warning or beach advisory has been issued, DES returns to affected water bodies on a weekly basis until the cyanobacteria standards are again met.

Cyanobacteria are natural components of water bodies worldwide, but blooms and surface scums may form when excess nutrients are available to the water. Some cyanobacteria produce toxins that are stored within the cells but released upon cell death, causing health effects that range in severity.

For more information, check the NHDES Beach Program website des.nh.gov/organization/divisions/water/wmb/beaches/index.htm.

DES cautions that people who notice anything resembling cyanobacteria should stay away and call staff officials to report a cyanobacteria bloom at (603)  848-8094.