HONOLULU – An elevated count of a specific type of bacteria, enterococcus, was measured in the treated effluent at the Sand Island Wastewater Treatment Plant (WWTP) on July 16, 2025, which was higher than the daily maximum limitation for enterococcus under the National Pollutant Discharge Elimination System (NPDES) permit for the Sand Island WWTP.
The sample was taken at the effluent monitoring station, within the plant, before discharging at the deep ocean outfall located approximately 9,120 feet from the shoreline at a depth of 230 feet below the surface of the water. Enterococcus analysis requires a 24-hour test. The result for the prior day of July 15, 2025 was also elevated; however, other recent prior results were within the daily permit limitations.
Results from samples taken by the city along the beach shoreline and nearshore samples collected in coastal waters on July 16, 2025 are well within water quality standards and indicate that there is no shoreward movement of effluent from the outfall.
The city will continue to monitor the treated effluent daily at the Sand Island WWTP and will collect daily samples at shoreline stations near the Sand Island WWTP until the data confirms that effluent enterococcus levels remain within the permit limit.
During this time, signs remain posted to stay out of waters around the outfall. This notification will be updated upon confirmation of the city’s additional monitoring efforts.
—PAU—
