Bacteria levels in coastal Alabama waters creeped up slightly from the first week of August: six sites tested above the “safe to swim” threshold for bacteria. Orange Street Pier in Fairhope was not tested due to construction, and four sites did not have updated data.

The Alabama Department of Environmental Management, the city of Daphne and Mobile Baykeeper all test the local waters at various locations for enterococcus, a bacteria that is a common cause of infections, according to the National Institutes of Health.

Both the Mobile Baykeeper and ADEM base their results on the same basic standard; The 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, whereas ADEM measures the level of enterococcus as number of bacteria colonies per 100 milliliters. According to the EPA, the “safe to swim” threshold for enterococcus is 104 per 100 mL.

When it comes to E. Coli, the EPA says the “safe to swim” threshold is 235 MPN, though E. Coli bacteria is only measured at one site.

Several sites did not have updated water quality testing results available. Those are listed as “Not updated” in the chart. Sites with the note “retest” means that the water was resampled a day later after the first water quality test came back with high levels of bacteria.