The state Health Department has 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.

The action takes place nearly two months after the incidents, documented as 13 days total between April and May, in which the Kailua Regional Wastewater Treatment Plant showed levels exceeding permits for enterococcus bacteria – an indicator of fecal material in water.

The financial penalty is due to the effluent discharges as well as the late submission of a required discharge monitoring report, the department said.

The exceedances were specifically above limits allowed by the National Pollutant Discharge Elimination System permit for the treatment plant.

“Discharge of pollutants above allowable limits into state waters is not acceptable,” said Kathleen Ho, deputy director of environmental health, in a news release. “We will continue to take action to protect public health and the environment.”

The Honolulu Department of Environmental Services said it acknowledges recent exceedances of enterococcus bacteria levels in the fully treated effluent discharged through the ocean outfall.

The city says immediate, corrective actions were taken, investigations conducted, and measures implemented to ensure compliance with the NPDES permit. It promptly notified DOH of the exceedances, issued news releases and posted signs at Kailua Bay warning the public to avoid waters around the outfall.

“Our staff investigated the exceedances, and we made immediate corrective actions, in addition to further optimizing the plant performance,” ENV Director Roger Babcock said in a city news release. “Laboratory tests of the samples gathered since May 5, 2023, established the enterococcus in the effluent is well within permit limits.”

The city also said it is planning to install an ultra violet disinfection system at its plant, which should be operational on or before December 2025, to significantly lower enterococcus levels.