How do beach managers determine when to issue a water quality advisory?
There are state standards for E. coli in recreational waters. The state standards are based on those recommended by USEPA and determined by earlier USEPA studies. In USEPA studies, investigators determined that when E. coli levels went up, the number of swimming-associated gastrointestinal illnesses also increased. The Ohio bathing-water standard for E. coli is a single-sample value of 235 colonies per 100 milliliters. If the count for E. coli is equal to or above 235, the beach manager will issue a water-quality advisory.
