Crystal Lake Reopened After Algae Advisory

On August 15th, Mayor Fuller announced that water testing results show algae in the water at the Crystal Lake swimming beach were at acceptable levels for regular recreation.

Crystal Lake reopened for regular activities on Thursday, August 15, at 2:00 pm.

The lake closed for the season on August 18th, as originally scheduled.

The Mayor’s August 15th update:

Results have been received from the second Crystal Lake water samples collected on Tuesday, August 13, 2019 and tested by the Massachusetts Department of Public Health (MDPH). Water testing was conducted because an algae bloom was observed at the lake beginning August 5. The results show algae in the water at the swimming beach are at acceptable levels for regular recreation.

Crystal Lake will reopen for regular activities on Thursday August 15 at 2:00 pm.

In accordance with MDPH guidelines, Crystal Lake was tested two times, one week apart, before determining whether the lake is at acceptable levels to be open. 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. 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.


Prior advisory

On August 7th, the City of Newton issued a notice that Crystal Lake would be closed to swimming for at least one week due to the presence of blue-green algae.  The advisory included these cautions:

  • Do not swim in Crystal Lake
  • Do not swallow water from Crystal Lake
  • Keep animals away from Crystal Lake
  • If accidental water contact occurs, rinse off immediately

Algae Can Poison Your Dog   (New York Times, August 13, 2019)

Read a newsletter article about the large algae bloom that closed Crystal Lake to swimming in August 2012