A beachwater bacteria advisory for Hauula Beach Park was posted today by the state Department of Health Clean Water Branch due to a water quality exceedance of enterococci, the fecal indicator bacteria frequently found in the presence of waterborne pathogens.

Levels of 344 enterococci per 100 milliliters were detected during routine beach monitoring, the branch announced today.

The threshold level is 130 enterococci per 100 mL.

“Swimming at beaches with pollution in the water may make you ill,” the branch warned, adding that children, elderly and people with weakened immune systems are the most likely to develop illnesses — most commonly gastroenteritis — or infections after coming into contact with polluted water.

Symptoms of gastroenteritis can include nausea, vomiting, stomachache, diarrhea, headache or fever, the branch said, noting these symptoms are also consistent with food poisoning.

It added that other minor illnesses associated with swimming include ear, eye, nose and throat infections, but that in highly polluted water, swimmers may occasionally be exposed to more serious diseases.

Warning signs have been posted, the branch said, and the advisory will remain in effect until water sample results no longer exceed the threshold.