Some beaches in Boston area posted due to public health concerns

By Jeff Fish, Globe Correspondent

Many beaches along the Massachusetts coast were closed to swimming today due to high bacteria levels in the water, according to the Department of Conservation and Recreation.

DCR spokeswoman Wendy Fox confirmed that three state-run beaches - Tenean Beach in Dorchester, Carson Beach in South Boston, and Wollaston Beach in Quincy - are posted. The bacteria is called enterococcus, which gives similar gastrointestinal symptoms to E. coli, said Fox.

The normal bacteria levels are 104 colony forming units, or cfu, per 100 milliliters. Both Carson and Tenean exceeded those levels, Fox said.

Beaches in 14 other Greater Boston communities, stretching from Beverly in the north to Chatham and Martha's Vineyard on the Cape, have been posted in the past several days due to high bacterial counts, according to a state website.

In Quincy, nine of the city's 13 beaches were posted today due to high bacterial counts, according to the city.

Because Wollaston Beach is so long, it has four sampling areas—Channing Street, Milton Street, Rice Road, and Sachem Street, said Fox. At three of the four sites, bacteria levels were in the unsafe ranking so the whole beach was closed, she said.

Fox said it usually takes one tidal cycle (12 hours) for the bacteria the wash away, but it could take Wollaston two to four cycles. “Wollaston is different because it’s very wide, very shallow, and very protected,” she said, adding that there are also four storm drains that empty into the water, making it more susceptible to the bacteria.

Many other beaches are closed due to bacteria levels. The state Department of Public Health maintains a website with test results.