It is the time of year when residents of Anne Arundel County's waterfront communities begin to think about heading to their neighborhood beaches for a dip - and the urge to hit the water means another warm-weather ritual is under way.
For the 28th year, the Severn River Association has begun Operation Clearwater, a program to provide areas on the Severn River with regular testing of the water quality in their swimming and water recreation spots.
During the 16-week program, which continues through Labor Day, test results are posted on the association's Web site, www.severnriver.org, and community representatives are notified of high bacteria counts, if any appear.
"'Is the water fit to swim in?' is the question we want to ask," said Sally Hornor, a professor of microbiology at Anne Arundel Community College, who runs Operation Clearwater out of the college's environmental center. "Generally, what the community wants sampled is the area where little children would swim, in the shallow water off the beach."
The Health Department conducts countywide water-quality testing at nearly 80 sites throughout the summer, but Operation Clearwater provides more detailed data to communities on the Severn River.
Testing for Operation Clearwater began May 15 at about 15 sites. Within the next few weeks that number probably will increase to 25, as more community associations sign up for the service, Hornor said.
Each Wednesday morning, one of Hornor's students - working for Operation Clearwater for the summer - collects water samples and brings them to the college lab for analysis. Hornor posts the data online the next day.
For the second year, Operation Clearwater is testing for the bacteria group enterococci, instead of fecal coliform bacteria. Both organisms are found in the intestines of warm-blooded animals, but recent studies have shown that the presence of enterococci bacteria is a more accurate indicator of water quality.
The Environmental Protection Agency recommends against swimming when enterococci counts exceed the accepted levels of 35 per 100 milliliters of water.
If the counts are above the recommended levels, Hornor notifies a contact for the area.
"Communities have various responses," she said. "Some regularly post data to let people know, some don't do anything.
"This is a way to let community members know what the status of the water quality is, and they can make their own decisions," Hornor said.