Notification of elevated bacterial level in the treated effluent at Sand Island WWTP
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) May 21, which exceeded the daily maximum limitation for enterococcus under the National Pollutant Discharge Elimination System (NPDES) permit for the 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 (1.7 miles) from the shoreline at a depth of 230 feet below the surface of the water. Enterococcus analysis requires a 24-hour test. The prior day of May 20, 2024, was within the normal range and within permit limitations.
The city initiated collecting additional daily samples at the five (5) shoreline stations located near the WWTP. Additionally, the city will continue to monitor the treated effluent at the WWTP daily.
During this time, signs are posted to stay out of waters around the outfall. This notification will be updated upon confirmation of the city’s additional monitoring efforts.
—PAU—