RIDOH and DEM Recommend Lifting Restrictions for Blue-green Algae in Slacks Reservoir Published on Wednesday, June 26, 2024 The Rhode Island Department of Health (RIDOH) and the Rhode Island Department of Environmental Management (DEM) recommend lifting the advisory restricting recreational activities at Slacks Reservoir Little Beach in Greenville. 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 Slacks Reservoir, 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. To report suspected blue-green algae blooms, contact RIDEM's Office of Water Resources at 222-4700 or DEM.OWRCyano@dem.ri.gov.