The U.S. Environmental Protection Agency has issued a new order to ensure the City and County of Honolulu meets pollutant discharge requirements at the Kailua Regional Wastewater Treatment Plant it owns and operates.
The “order on consent” follows a previous one in December, the EPA said, and is necessitated by the fact that the plant has continued to exceed effluent limits for bacteria.
In April and May the plant exceeded limits for enterococcus bacteria in its effluent on 13 different days. Enterococcus is an indicator of fecal material in water and possible pathogens that can sicken swimmers.
The state Department of Health in June fined the city $434,350 for the effluent discharges, a violation of the state-issued National Pollutant Discharge Elimination System permit, along with the late submission of a required report.
The exceedances were concerning, DOH said, given that they were four to six times the permitted level on some days.
To prevent further exceedances, EPA is requiring the facility to install new disinfection treatment technology to treat all effluent from the plant to ensure compliance with bacteria levels established in its Clean Water Act permit.
Additionally, EPA is requiring the plant to perform major repairs to the biological treatment units, or “biotowers,” to prevent additional failures.
“This order ensures that the Kailua Treatment Plant continues to take steps to prevent any further bacteria exceedances in what the plant discharges into the ocean,” said EPA Pacific Southwest Regional Administrator Martha Guzman in a news release. “Compliance with the Clean Water Act permit is essential to protecting public health and Hawaii’s coastal waters. With our partners at Hawaii Department of Health, we will continue to provide vigilant oversight over Hawaii’s wastewater plants.”
The first consent order in 2022 was based on the failure of one of the two biotower treatment units at the Kailua wastewater treatment plant in January 2021.
In that order, EPA required the city to complete an assessment of the biotowers and increase enterococcus effluent monitoring.
The city in April submitted the assessment, identifying needed repairs, replacements and preventive maintenance for both biotowers.
The new order, which terminates the previous one upon effect, requires that a construction contract for the biotower rehabilitation be in place by January 2026 and that it be substantially completed by January 2029.
The Honolulu Department of Environmental Services issued its own news release, saying that although some of these exceedances occurred during statewide brown- water advisories issued by DOH, it strove to notify and update the public and department of the events.
At that time, the city was complying with the terms of the EPA’s order addressing the 2021 incident at the treatment plant.
The city 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.
“As previously reported, the city has budgeted $45 million for upgrades to KRWWTP, including $11 million for an ultraviolet disinfection system,” the city said in the release. “The city is actively advancing the implementation of the new UV disinfection system while concurrently in the planning stage for biotower modifications.”
The city also said it is committed to complying with the terms of this order and has already made significant progress toward fulfilling several requirements.
“ENV continues to work collaboratively with both DOH and the EPA to ensure KRWWTP remains in compliance with its NPDES permit,” said the city.
EPA officials did not visit the Kailua wastewater treatment plant for this order, but requested records from the city.
The city-operated Kailua treatment plant treats up to 15 million gallons per day of wastewater collected from the Ahuimanu, Kaneohe and Kailua communities. Under the state NPDES, it is authorized to discharge treated wastewater to an outfall off the Mokapu Peninsula.
Separately, EPA has a consent decree with Honolulu requiring upgrades to the Sand Island and Honouliuli wastewater treatment plants, which must be completed by 2035.
