Seven beaches in Quincy and two in Hingham have been closed to swimming because of bacteria contamination.

Mound Beach was 11 times over the maximum considered safe, Merrymount Beach was eight times over and Delano (Back) was three times over. Broady (Baker) and Germantown Fire Station beaches were slightly over the limit.

The Channing Street and Sachem Street sections of Wollaston Beach were also closed as a precaution, although the water tested within safe limits.

Kimball Beach is Hingham was more than 20 times the limit and Wompatuck Beach was almost three times the limit.

Health officials in both communities attribute the high readings to the heavy rain on Tuesday. The water has been retested.

With heavy rains expected on Thursday, contamination levels are likely to spike at other beaches in the coming days.

All other beaches on the South Shore are open.

See water quality test results for each community and for Cape Cod, the South Coast and North Shore.

For more on Quincy beaches, call 617-376-1288, or visit tinyurl.com/ledger-quincy-beaches. For more on Wollaston Beach, call 617-626-4972.

Seventy-five salt water beaches on the South Shore are tested for enterococci, intestinal bacteria found in humans and animals. High levels of enterococci indicate the waters may also contain other disease-causing microbes that are present in sewage but are more difficult to detect. Bacterial colonies are filtered from three ounces of water and placed on a gel infused with nutrients and chemicals designed to promote growth. Left in an incubator, the single cells isolated on the filter grow explosively, forming colonies visible to the naked eye.After one day, the colonies are counted and if they exceed 104 colonies, the beach is closed to swimming.

Read the original post:

Seven beaches in Quincy, two in Hingham closed