The Florida Department of health monitors beaches throughout the state as part of the Florida Healthy Beaches Program for enterococci bacteria and then determines whether those beaches are safe for swimming or not.
Enterococci are bacteria that normally inhabit the intestinal track of humans and animals. The presence of this bacteria can be an indication of fecal pollution, which may come from stormwater runoff, pets and wildlife, and human sewage. Exposure to these bacteria while swimming or recreating on the water may cause disease, infections, or rashes.
If an enterococci result exceeds 70 colony forming units per 100 mL of beach water sampled, and a resampling also exceeds this value, then an "advisory" would be issued for the sampling site. This advisory is a warning to those who want to swim or recreate that the area is not safe to do so.