The Arlington Health Department issued a public health advisory for Hill’s Pond at Menotomy Rocks Park due to a high level of blue-green algae. The Health Department strongly advises residents not to swim or stand in the water and urges residents to keep pets away from the water due to risks associated algae.  

A harmful algal bloom (HAB) is an overgrowth of algae in a water body that may affect water quality and aquatic life. Some HABs produced by bacteria can create toxin that may also harm people, animals, and the local environment. 

During an algae bloom, the amount of algae and toxins in the water can become elevated and exposure can be potentially harmful to people and animals. Contact with high levels of a harmful algal bloom have been found to contribute to eye, ear, and skin irritation.  Ingestion of elevated concentrations of the algae and its toxin can lead to serious health effects including muscle cramps, twitching, and liver damage. More information can be found on the MA Department of Public Health’s website.