Local officials are warning the public to stay out of water in the Mamala Bay area after detecting high levels of the Enterococcus bacteria in the area.

The state Department of Health said that elevated counts of the bacteria were found at the Honouliuli Wastewater Treatment Plant Thursday morning. The plant’s ocean outfall exceeded permitted fecal indicator bacteria levels.

The City and County of Honolulu is posting warning signs at shoreline stations along the Ewa coastline — at the Nimitz Beach, White Plains Beach, Oneula Beach Park and Ewa Beach Park. It will be monitoring bacteria levels daily in the plant’s effluent and and in the shoreline monitoring stations to ensure the bacteria levels remain low.

The city is currently investigating the cause of the incident.

The public is advised to stay out of the affected waters until the warning signs have been removed.