WASHINGTON – Thinking about beating the heat with a dip in the Potomac? You’d be smart to stick to designated areas. Even then, remember to take necessary precautions.

“Areas that are not designated as public beaches are not tested frequently,” says Joe Hoffman, executive director for the Interstate Commission on the Potomac River Basin.

“They might be tested once a month, once every two months and people have to weigh the risk of swimming in these areas.”

In designated beach areas, such as Fairview Beach in Virginia, water is tested weekly for several types of bacteria that can cause gastrointestinal illness and other infections.

A big part of the contamination happens when storms wash animal waste from cows, deer and other wildlife into waterways.

An influx of Canadian geese is leaving its mark.

“They produce waste matter that ends up on the ground and, after a rainstorm, comes into the rivers and waterways,” Hoffman says.

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