Rhode Island officials on Wednesday lifted recreational warnings at two freshwater ponds after follow-up sampling found low algae levels and no detectable toxins. The Rhode Island Department of Environmental Management said Johnson’s Pond, also known as Flat River Reservoir, in Coventry and Lake Washington in Glocester now meet the state’s safety guidelines.
The decision applies only to those two water bodies. It does not amount to an all-clear for every lake and pond in Rhode Island, and officials cautioned that cyanobacteria conditions can change quickly. Residents should continue to avoid water where surface scum appears, especially material that resembles green paint, pea soup or cottage cheese.
State agencies issue these recommendations when sampling or visible conditions indicate a potentially harmful bloom. They lift them after follow-up testing shows that algae density and toxin concentrations have returned to acceptable levels. Because a bloom can disappear before toxins fully break down, appearance alone is not enough to determine that previously affected water is safe.
Cyanobacteria are naturally present in fresh water, but warm conditions and excess nutrients can fuel rapid growth. The U.S. Environmental Protection Agency explains that dense blooms can interfere with recreation, deplete oxygen and produce unpleasant odors. Some species also release cyanotoxins, which cannot be identified by sight alone.
That uncertainty is why the state’s warning remains practical even after a specific advisory is lifted. The EPA says recreational exposure to harmful algal blooms can cause skin irritation, respiratory symptoms or gastrointestinal illness; more serious effects are possible but uncommon. People who believe they were exposed should rinse with clean water and contact a medical professional or Poison Help if symptoms develop.
Rhode Island’s standing guidance is also stricter for children and pets because they are more likely to swallow water or contact shoreline scum. In a broader advisory issued earlier this year, the health and environmental agencies told the public not to drink untreated pond water, eat fish from affected waters or let animals swim in visible blooms. Boiling does not reliably remove cyanotoxins and may concentrate them.
For Johnson’s Pond and Lake Washington, the latest laboratory results support reopening normal recreation. But the lifting of an advisory is a point-in-time decision based on samples, not a guarantee that conditions will remain unchanged. Wind can move surface accumulations, and bloom intensity may vary across the same pond.
Officials therefore recommend a simple visual check before swimming, paddling or allowing pets near the water. If suspicious algae are present, people should stay out and keep animals away even if no formal advisory is posted. Suspected blooms can be reported to DEM’s Office of Water Resources so the state can investigate and, when warranted, arrange testing.
The updated status removes two sites from Rhode Island’s active caution list while preserving the state’s broader message: laboratory results determine when a warning can be lifted, but day-to-day observation remains the first line of protection for lake users.
