Health Director Shaun McAuliffe announced Friday morning that cyanobacteria levels at the Hopkinton Reservoir’s Upper Beach have dropped for the second straight week, making it safe for swimming during the first heatwave in August.

The Massachusetts Deprtment of Health’s Public Health’s interactive beach water quality dashboard confirmed Friday morning that no beaches are closed in either Hopkinton or Ashland.

“MDPH collected a water sample from Hopkinton Reservoir at the Upper Beach on Monday, July 29,” McAuliffe stated in an email to the Independent. “Laboratory analysis showed cyanobacteria levels of 3,700 cells/ml, which is below the MDPH guideline level of 70,000 cells/ml. The toxin microcystin was not detected in the sample.”

He added that MDPH requires two consecutive weeks of low cyanobacteria levels in order for a beach to be removed from the beach closure list. Hopkinton has had low levels of these blue-green algae pools for two consecutive weeks. The latest testing results should be available by 5 p.m. Friday.

McAuliffe noted that Sandy Beach has not been closed this summer related to poor water quality. He added that the weed treatment spraying has been successful. Both the Conservation Commission and the Select Board in March approved the application of two herbicide to control the weed growth. At the March Select Board meeting, Department of Public Works Director Kerry Reed explained to the Select Board that this action was necessary because the weed population has grown “in density and diversity.”  Targeted application began in early June to the northern basin, north of Sandy Beach up to West Main Street.

Lake Maspenock advocates had been pushing for the limited application of herbicides since last September after years of trying to find a solution for the weed overgrowth.

SOLitude Lake Management, a nationwide company used to test water issues related to algae and weeds, recently completed a post-treatment survey of the lakefront, added McAuliffe. The report concluded that “in general, it appears the weed treatment was successful.” 

“The survey results and the feedback I’ve received from the public suggest a significant reduction of weeds and improved recreational use,” McAuliffe noted. “To me, this was the final step for the 2024 treatment project. The DPW will do a regular scheduled drawdown of the lake this year and will request to do an extended drawdown next year in 2025. The DPW will continue to work with the Lake Maspenock Weed Management Citizen Input Group for recommended actions for next year.”