What is Enterococci and Why Do We Track It?

Enterococci bacteria normally inhabit the intestinal tract of humans and animals. The presence of enteric bacteria can indicate fecal pollution, which can come from stormwater runoff, pets and wildlife, and human sewage. The Department of Health uses enterococci as key fecal indicator bacteria because they correlate strongly with swimming-associated gastrointestinal illness, especially in marine water. If these bacteria are present in high concentrations in recreational waters, it poses a risk for humans in the water. Scientific studies show that if enterococci bacteria are ingested while swimming, or enter the skin through a cut or sore, they may cause illness or infections.

According to studies conducted by the Environmental Protection Agency, enterococci have a greater correlation with swimming-associated gastrointestinal illness in marine and fresh waters than other bacterial indicator organisms, and are less likely to die off in saltwater. If an enterococci result exceeds 70 cells per 100 milliliters (mL) of marine water sampled, then an Advisory should be issued for the site.

Suncoast Waterkeeper currently monitors 19 sites for enterococci bacteria, and we analyze annual trends in a year-end review which we share to our members, the public, and local officials. 

Click HERE to see our latest Suncoast Safe to Swim Summary Review for 2025.

Click HERE to view our 2024 Summary Review.

Our enterococci data is available to the public.  Click HERE to view our results from 2022 to 2025..