Worcester Will Treat For Toxic Algae Thursday

WORCESTER, MA — Worcester residents should avoid Indian Lake and the Coes Reservoir on Thursday as the city parks department treats the water to prevent the growth of toxic algae.

The city Department of Public Works will apply copper sulfate to the water, which helps prevent the growth of algae containing cyanobacteria. Toxic algae can cause skin irritation and sickness if ingested. In extreme cases, cyanobacteria can kill humans and pets.

Copper sulfate can be harmful if you come in direct contact with it, but the substance dissolves quickly in water. It stops algae growth by preventing photosynthesis, according to the National Pesticide Information Center.

"We advise all persons to stay out of the water, discontinue boat use and fishing and keep their pets out of the water on this day. Beaches will be posted prior to the application," Worcester DPW said in a statement this week.

Beaches will reopen following the treatment, according to DPW.

Algae blooms are caused by a number of factors, including sunlight, stagnant water, and too much nitrogen and phosphorous in the water, according to the U.S. Environmental Protection Agency.