Attention mothers: you can relax (about water quality) this weekend

Water at swim areas has been exceptionally clean this week, thanks to dry weather. If forecasts hold and we get only light showers today and tonight (Friday) we should enjoy care-free bathing through the weekend.

Here were the few problem areas this week, swimming areas with unhealthy bacteria levels:

MAGOTHY

Dividing Creek (upstream) – 430

SOUTH

Glen Isle – 420

Davidson Wildlife Sanctuary – 150

RHODE

Cadle Creek Community Dock – 178

The acceptable level of enterococci bacteria is 104 or fewer bacteria colonies per 100 milliliters of water.

Enterococci are bacteria that are found in the GI tract of warm-blooded animals, which includes all birds and mammals.  Their presence in surface water indicates recent contamination with fecal waste. 

Rainwater washes contaminants such as dog waste, waste from leaking septics and wildlife waste from the landscape. Heavy rains also cause occasional sewage overflows and spills that also contribute bacteria.

Both the county health department and a network of volunteers test over 100 public beaches and other areas around the county for bacteria. The results from the county tests are put online here, and for the volunteer tests here for Severn and Magothy rivers, here for South River, and here for Rhode/West River.  All the sites listed above were tested by Watershed Stewards.

But the tests are really most useful for only a few days. Water quality can improve or degrade fairly quickly depending on whether it has rained. For that reason the county health department cautions residents to avoid swimming or direct contact with any “natural” water (swimming pools don’t count) for 48 hours after a rain of ½ inch or more.

Unfortunately, the county doesn’t do much to publicize when such storms and conditions occur. People often swim when the sun comes out after a big storm. That’s when conditions are worst.

Be safe. Have fun.