OKLAHOMA CITY -- The Oklahoma Department of Environmental Quality is issuing an alert about the safety of swimming holes this Fourth of July. The organization estimates about 300 bodies of water in the state are contaminated with dangerous bacteria.

“Any time you swim in a body of untreated water, a lake, a river or even a farm pond, there is a possibility there is bacteria present in the water,” said Skylar McElhaney of the DEQ.

McElhaney didn’t single out any one particular body of water, but said all have varying levels of bacteria, including E. coli and cryptosporidium.

DEQ experts suggest anyone who plans to swim below the surface should wear goggles, take care not to swallow any water, and to scrub down after the swim.

“Take a shower with clean water and soap after you get out of the water,” said McElhaney. “Especially if you have cuts or scrapes.”

Exposure to the bacteria can cause problems ranging from ear infections to meningitis.

DEQ is taking steps to try and reduce the amount of bacteria in untreated water, including trying to limit the amount of runoff going into lakes and rivers.