Bacteria Water

Two Berkshire Beaches Closed, One for Bacterial Exceedance –

Lulu Pond has been closed for swimming due to high bacteria concentration.

PITTSFIELD, Mass. Two Berkshire beaches have been closed to swimming in advance of the Fourth-of-July weekend.

Lulu Pond, in Pittsfield State Forest, had a bacterial over-limit and Lake Mansfield is closed in Great Barrington for “other” reason. Other recreational activities are permitted while the waterbodies have been closed to swimming.

On June 24, Lulu Pond was contaminated with 488.4 colony forming units of Enterococci per 100 milliliters, a level that is significantly higher than the threshold for freshwater beaches of 61 CFU/100 ml. The number was up from 2 cfu/100ml on the 17th of June, closing the beach.

On July 1, there were 204.6 cfu/100ml.

Enterococci bacteria is a type indicator organism that can be found in the intestines warm-blooded mammals and humans. They are frequently associated with fecal contaminants. Indicator organisms can be used to detect pathogens that are associated with fecal contaminants in water, since they are hard to measure.

Enterococci, and E. coli are the bacteria that are used to test water at beaches. Enterococci is tested on marine beaches. “Freshwater beaches are either tested for the presence E. coli, or Enterococci.”

Signs warn that swimming can cause illness. A flag sways on the shore, warning people not to go into the water.

Two consecutive violations are considered unsafe to swim at most beaches in Massachusetts. Beaches with a long history of multiple-day violations are required by law to post their warnings after only one violation.

Lake Mansfield may be closed for “others” reasons. These can include issues that are not related to bacteria, such as damage from storms, issues with visibility and clarity of the water, or repairs. Local authorities determine this and it can have nothing to do with water testing.

MDPH reported that “for the beaches currently shut down due to ‘others’ reasons’, these include missed sampling/testing as well as flooding on the beach and road maintenance.

There are more than 30 road closures in the state.

York Lake Beach, New Marlborough, was closed on June 24, when the Enterococci exceeded 209.8 cfu/100ml. It reopened on July 1, after it dropped to 11.9.

MDPH explained that beaches closed due to high bacteria levels could reopen if a test shows levels of bacteria below DPH standards.

While the frequency of testing at Massachusetts beaches varies, many beach operators choose to test the water immediately after a beach closure or a result with high bacteria, rather than waiting for the next scheduled tests.

The timing and number of beach closures are affected by environmental factors and rainfall. In Massachusetts, on July 10, 2023 there will be 53 beach closures, while in the same period in 2022 there will be 40. On July 2, 42 beaches were closed.

Swimming in unsafe water can cause gastrointestinal (nausea and vomiting), respiratory (cough, runny or blocked nose, sneezing), eye and ear (irritation, earache and itching) and flu like symptoms (fever, chills and fever) symptoms.

Children, seniors and those with compromised immunity are more at risk. While the majority of illnesses are minor, some can be serious. If you feel ill after swimming at a closed-off beach, it is important to consult a doctor.

A beach posting does NOT mean that anyone is prohibited from going to the beach or that it prevents them from doing so. “If a beach has a posting, it means that swimming is prohibited,” MDPH clarified.

There are many safe activities that people can do on the beach without getting in the water. These include walking along the coast, sunbathing, collecting seashells/seaglass, and playing sports like paddleball, football, Frisbee, or volleyball.


The accepted level for Enterococci at marine beaches is 104 colony forming units (cfu/100ml) or less.

The maximum level of Enterococci that can be found in a freshwater sample is 61 CFU/100 ml. Freshwater limits are stricter than ocean water because higher levels of bacteria in a smaller area of water can cause illness. E. coli can be tested on freshwater beaches instead of Enterococci. The acceptable level of E. Coli for a single water sample is below 235 cfu/100ml.

MDPH has also set a limit on the last five test results for a particular beach, known as the geomean. The geomean is meant to reflect the water quality during a prior time period (typically one month). The geomean of Enterococci at marine beaches is 35 cfu/100ml. The geomean of E. coli at freshwater beaches is 126 cfu/100 ml, and that of Enterococci 33 cfu/100 ml.

You can find the test results of individual beaches on MDPH’s Interactive Beach Water Quality dashboard. DPH updates its beach closures daily. Data from previous years is summarized in DPH Annual beach reports.

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