By Tiffany Williams
Worcester, MA — The City of Worcester Department of Sustainability and Resilience will conduct a preventative copper sulfate treatment at Indian Lake on Thursday, August 14, 2025.
Officials emphasize that there is currently no threat of harmful algae exposure. The treatment is intended to prevent the growth of cyanobacteria, a toxin-producing blue-green algae that can be harmful to humans and pets when present in high concentrations.
On the day of the treatment, residents are advised to stay out of the water, avoid boating, and keep pets away from the lake. Water from Indian Lake should not be used for irrigation, lawn watering, or livestock during this period. Beaches will be posted prior to the application, and water use restrictions are expected to be lifted the following day.
Copper sulfate is a common, safe, and effective method used to control cyanobacteria growth. The Worcester Conservation Commission has approved the application, which poses minimal risk to people and animals after the treatment is complete.