Now that school is out and summer is in full swing, more and more people are looking to coastal Alabama’s abundant natural resources for things to do, including places to swim.

The Alabama Department of Environmental Management, Mobile Baykeeper and the city of Daphne all test the local waters at various locations to determine if the water is safe. Specifically, the agencies test for enterococcus, a bacteria that is a common cause of infections, including UTIs, bacteremia and infective endocarditis, according to the National Institutes of Health.

Mobile Baykeeper, which runs the Swim Where It’s Monitored (SWIM) program from April-September, measures the bacteria level as a “Most Probable Number” (MPN), a statistical measurement. According to the EPA, the “safe to swim” threshold for enterococcus in MPN is 104. The “safe to swim” threshold for E. Coli is 235 MPN, though E. Coli bacteria is only measured at one site.

ADEM measures the level of enterococcus as number of bacteria colonies per 100 milliliters. The threshold in that measurement is 104 per 100 mL.

[Here’s a printable version of this chart.]