E. coli warning issued for some Folsom Lake State Recreation Area sites

California State Parks has issued a health alert for visitors after elevated levels of E. coli bacteria were found at some areas of the Folsom Lake State Recreation Area.

The Central Valley Regional Water Quality Control Board identified elevated E. coli levels at Willow Creek Day Use Area, Nimbus Flats and Black Miners Bar Day Use Beach, State Parks said Friday.

The samples were collected in late June from near-shore locations, officials said.

"While most E. coli strains are harmless and present at low levels in most waterbodies, it is essential to be cautious when concentration levels are elevated," State Parks officials said in a statement.

Officials are also monitoring for cyanobacteria and nuisance algae in freshwater and estuarine waterbodies.

Visitors are being urged not to drink from lakes or rivers, avoid swimming with open wounds and shower after going into the water.

Additional E. coli testing will continue throughout the summer, State Parks said.