Though recent weather has been warm enough to enjoy some outdoor enrichment, the town is advising residents to stay clear of Hill’s Pond at Menotomy Rocks Park, due to high levels of blue-green algae.
The Arlington Health Department reported Oct. 1 that the body of water is experiencing an overgrowth of algae that may affect the water quality and aquatic life. The toxins in the blue-green algae can be harmful to people, animals and the local environment.
Residents are being told not to swim or stand in the water, and to keep pets away.
According to the state Department of Public Health, exposure to the high levels of harmful algae can lead to eye, ear and skin irritation. Ingestion of the algae has been known to contribute to serious health effects, including muscle cramps, twitching and liver damage.
The town has not yet reported when the pond will be safe for public visitation.
This story, written using information from the town, was published on Oct. 7, 2025.
