Rain advisory closes Suffolk beaches to swimming after runoff concerns

Families heading to Suffolk County beaches were told to stay out of the water after heavy rain and stormwater runoff raised bacteria concerns at beaches across the North and South shore. Health officials said the advisory covered 83 beaches in Nassau and Suffolk counties, a precaution meant to keep swimmers, surfers and anyone wading near the shoreline away from water that could carry elevated bacteria after the storm.

The warning mattered most for people planning weekend trips to places tied to sheltered water, where contamination can linger. Suffolk County said many of the beaches under advisory sit in embayments or near stormwater discharges with limited tidal flushing, including stretches influenced by Great South Bay, Cold Spring Harbor, Huntington Harbor, the Port Jefferson Harbor Complex, Stony Brook Harbor and Long Island Sound. County officials said bathing and other direct water contact should be suspended until the water has been flushed by two successive tidal cycles, or at least 24 hours after the rain ends, unless sampling still shows elevated bacteria.

The problem is tied to runoff, not some countywide ocean condition. New York State Department of Health guidance says heavy rain can increase fecal contamination in coastal waters, and that the bacteria can come from combined sewer overflows, faulty septic systems and animal waste washed into drains and tributaries. State beach standards are exceeded when enterococci levels rise above 104 colonies per 100 milliliters, a measure health officials use to decide when bathing should be discouraged or stopped.

The Memorial Day weekend was already wet across the New York area, with CBS News New York reporting that 1 to 2 inches of rain had fallen and more was expected, adding to the runoff risk that triggered the warning. Nassau County Department of Health said its own advisory covered 18 beaches and would remain in effect until 7 a.m. Sunday unless more heavy rain fell or sample results showed elevated bacteria. PIX11 reported Nassau’s advisory had initially covered 20 beaches and was expected to last until Tuesday morning while officials monitored water conditions.

Suffolk County says its beach monitoring program covers more than 190 beaches countywide, and the county has repeatedly issued rainfall-related bathing advisories in recent years, including warnings affecting 61, 62, 63 and 49 beaches. Officials have framed the monitoring as both a health protection and an economic necessity, since the county’s beaches draw summer traffic from across Long Island.