How Florida beach water testing works

Florida's county health departments sample the water at about 350 beaches, usually every two weeks, and test it for bacteria. This site gathers every result in one place.

What's tested

Staff wade in to knee depth and fill a sterile bottle. A certified lab counts enterococci, bacteria that live in the intestines of people and animals. Enterococci rarely make people sick on their own, but they travel with the germs that do, so a high count is a sign the water may contain sewage, stormwater runoff or animal waste. Swimming in that water can cause stomach illness, skin rashes, and ear, eye and sinus infections. Children, older adults and anyone with a weak immune system are most at risk.

What the ratings mean

• Good 0 to 35 enterococci per 100 mL of water.
• Moderate 36 to 70.
• Poor 71 or more. The state usually takes a new sample to confirm it. If it's still high, or the first result is very high, the county issues a health advisory and posts signs at the beach saying swimming is not recommended. The advisory lifts when a retest comes back clean.

"No result" means no sample was taken (often because of weather) or the lab didn't report one. Results below the lab's detection limit are shown as <10.

Reading a result

Each result shows the water on the morning it was sampled, and lab results take a day or two. Bacteria levels rise after heavy rain, when storm drains and rivers wash bacteria to the shore, and fall again within a day or two. A beach with one Poor result in years of Good ones is usually a clean beach that had a bad day. A beach that tests Poor again and again has a lasting source of pollution. That's why every beach page shows the full history, not just the latest test.

Signs at the beach and lifeguards have the final word. Advisories are posted by the county health department, sometimes before the results reach any website.

Where the data comes from

• Latest results and advisories: the Florida Department of Health's Healthy Beaches Program beach detail pages, checked twice a week.
• History back to 2000: the state's yearly submissions to EPA's Water Quality Portal (organization 21FLDOH_WQX).
• Sampling site names and locations: the state's beach sampling map.

Beach names are the state's sampling-site names, which are often a park, street, pier or access point rather than the beach's everyday name. We don't change or interpret results; ratings follow the state's levels.

Florida Beach Water is published by MMR Internet, LLC, which also publishes visitor guides to parks in Florida and other states. It isn't affiliated with the Florida Department of Health or any county.