With temperatures expected to top 90 on Friday, three beaches in Scituate, two in Plymouth and one each in Quincy and Hull have been closed because of unhealthy bacteria levels.

In Plymouth, the north end of White Horse Beach tested at 35 times the maximum considered safe for swimming and the middle section of Plymouth Beach was 31 times over.

In Scituate, Peggotty Beach was five times the limit and Lighthouse Beach was three times over. Egypt Beach in Scituate was under the limit, but is closed because contamination was high in three previous tests.

The bacteria counts were three times the limit at the Sachem Street section of Wollaston Beach in Quincy was three times the maximum and 65 percent over the limit at the bay side of the A Street Beach in Hull.

New water samples have been taken and the results are expected on Friday.

The other 53 beaches on the South Shore that are tested weekly are open.

Testing ends this week in Quincy.

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.

Originally posted here:

7 beaches in Scituate, Plymouth, Quincy and Hull closed