Crystal Lake In Newton Is Open After Algae Scare

NEWTON, MA — Swimmers, boaters and fishers rejoice: Crystal Lake is back open after an algae scare prompted the city to close the water body earlier this month. On Aug. 5, someone spotted an algae bloom, which prompted testing and the subsequent closure, out of an abundance of caution.

Results of two later tests by the Massachusetts Department of Public Health show algae in the water at the swimming beach are at acceptable levels. Both samples indicated algae levels were below levels considered toxic.

"The initial laboratory analysis of the water sample collected on Tuesday, August 6 showed a cyanobacteria level of 39,000 cells/ml, below the MDPH guideline level of 70,000 cells/ml. The microcystin toxin level was <1 ppb, which is below the recommended level of 14 ppb," according to the city. "The second laboratory analysis of the water sample collected on Tuesday, August 13 showed cyanobacteria levels of 2,900 cells/ml, below the MDPH guideline level of 70,000 cells/ml. The microcystin toxin level was <1 ppb."

The commissioner of health and human services gave the all-clear Thursday. This means the lake will be swimmable and activities back to normal until the end of season on Aug. 18.

Blue-green algae, of the type health officials were concerned about, produce toxins that can make pets and people sick if they swallow the water, have direct skin contact, or inhale water droplets.

Cyanobacteria blooms have been fairly common in recent years in the Charles and in Crystal Lake. There were blooms reported in 2017, 2016 and 2015. Phosphorus pollution that collect on roads and parking lots then drains into the water body and helps the blue-green sheets of algae grow.

If a bloom or extra high readings are detected, the state will collect water samples on a weekly basis until cell counts drop to safe levels.

RELATED:

• Public Health Advisory: Algae Bloom At Crystal Lake (Aug. 6)
• Crystal Lake Is Closed: No Swimming, No Pets In The Water (Aug. 7)
• Algae Levels Low, But Still No Swimming At Crystal Lake(Aug. 8)

Patch reporter Jenna Fisher can be reached at Jenna.Fisher@patch.com or by calling 617-942-0474. Follow her on Twitter and Instagram (@ReporterJenna).