City officials Friday reported higher than permitted levels of enterococcus in a single sample of effluent from the Kailua Regional Wastewater Treatment Plant.
The sample, which was taken at 8:08 a.m. Thursday, exceeded the single sample daily maximum limitation for enterococcus under the National Pollutant Discharge Elimination System permit for the plant, according to a news release from the Honolulu Department of Environmental Services.
Enterococcus bacteria are used as an indicator of fecal material in water and possible presence of pathogens that can sicken swimmers.
The sample was taken at the effluent monitoring station at the plant before discharge at the deep ocean outfall about a mile from the shoreline at Kailua Bay.
The City and County of Honolulu said it received the result Friday after the 24-hour test and that it is now collecting additional daily samples of treated effluent at the Kailua plant.
Results from the additional testing will be provided when available, officials said.
The city said it has also begun collecting daily samples at seven shoreline stations near the Kailua treatment plant, which will continue until it has confirmed effluent enterococcus levels remain within the permit limit.
When ocean conditions are safe enough, the city said, it will also conduct monitoring at stations around the outfall at Kailua Bay.
Signs have been posted to alert the public to stay out of waters around the outfall.
The state Department of Health has also issued a brown-water advisory for Oahu. The advisory was issued Thursday after torrential rain from Wednesday resulted in stormwater runoff entering coastal waters.
In June, DOH fined the City and County of Honolulu $434,350 for discharging effluent exceeding permit limits for enterococci from its wastewater treatment plant into Kailua Bay on 13 days in March and April.
Due to those exceedances, the U.S. Environmental Protection Agency in September issued a consent order to the city to ensure pollutant discharge requirements at the Kailua plant are met.
The Kailua plant treats up to 15 million gallons per day of wastewater collected from the Ahuimanu, Kaneohe and Kailua communities. It is authorized by the NPDES permit to discharge treated wastewater to an outfall off of the Mokapu Peninsula.
The city has said it plans to install an ultraviolet disinfection system at its plant, which should be operational on or before December 2025, to significantly lower enterococcus levels.
