By Staff Reports
(Honolulu) – The City and County of Honolulu’s Department of Environmental Services (ENV) provides the following update regarding the Kailua Regional Wastewater Treatment Plant (WWTP):
The test result of an effluent sample taken March 15, 2025, has shown the enterococcus bacteria count is within the daily National Pollutant Discharge Elimination System (NPDES) permit limit for the Kailua Regional WWTP, and the March 14 exceedance is not continuing.
As part of its ongoing mitigative efforts, the city has been using a low dose of Peracetic Acid (PAA) in the treatment process to help further reduce bacteria levels and improve water quality. The full-scale implementation of PAA for disinfection began Feb. 25, 2025. PAA is an environmentally-friendly disinfectant that helps to reduce bacteria and pathogens in wastewater. ENV continues to refine and optimize this new process. Additionally, CCH is in the process of constructing a new ultraviolet disinfection (UV) system, which is anticipated to be complete by Dec. 31, 2025.
The city remains committed to transparency and public safety. Water quality samples are regularly collected at seven shoreline stations in Kailua Bay near the WWTP and are posted in real time on the ENV Kailua Shoreline Water Quality website. The public is encouraged to visit this site to stay informed and make decisions regarding recreational activities in the area.
