The Rhode Island Department of Health (RIDOH) and the Rhode Island Department of Environmental Management (DEM) recommend lifting the advisory restricting recreational activities at Slack Reservoir in Smithfield and Johnston. The advisory was related to high levels of blue-green algae, also known as cyanobacteria.
Recent consecutive surveys and sample analysis confirmed that blue-green algae has been present but at acceptably low levels and that cyanotoxin is not present in detectable concentrations. These findings meet the advisory guidelines and support lifting the advisory.
Blue-green algae conditions can change quickly, and it is possible that blooms may affect Slack Reservoir again, or other waterbodies in Rhode Island. The public should avoid contact with any body of water that is bright green or has a dense, floating algal mat on the water's surface. Blue-green algae blooms may look like green paint or thick pea soup. Toxins may persist in the water after a blue-green algae bloom is no longer visible.
For more information and a list of current and historical advisories, go to www.dem.ri.gov/bluegreen. Please send reports of suspected blue-green algae blooms, along with photographs, if possible to DEM.OWRCyano@dem.ri.gov.