600,000 gallons of partially treated sewage spills offshore
Nearly 600,000 gallons of partially treated sewage was discharged Wednesday from a deep-ocean pipe for the Honouliuli Wastewater Treatment Plant, according to city officials.
The Barbers Point "outfall" pipe is more than two miles offshore, at a depth of 200 feet, "so the bypass is expected to have negligible effects on the environment," according to a city news release distributed just before 6 p.m. yesterday.
Although the spill happened on Wednesday afternoon, city officials did not issue a news release until yesterday evening.
When spills occur on land or in nearshore waters, city officials "have to do a press release right away, and signage and sampling is right away, like clockwork," said Watson Okubo, who is in charge of water quality testing for the state.
But Okubo was not sure of the protocol when the incident is at a deep-ocean outfall.
Ken Shimizu, city Department of Environmental Services deputy director, said last night that city officials did what they are required to do.
"We called the Department of Health within 24 hours, and they instructed us to get a quantity of what was lost. When we got that figure, then we issued a press release," he said.
An estimated 597,524 gallons of partially treated waste water was discharged before all of the solids in it had settled to the bottom of a clarifier at the plant, the release said.
Much of the discharge was diluted with effluent that had received full treatment, Shimizu said.
The incident is the largest sewage release on Oahu since 48 million gallons of raw sewage was discharged into the Ala Wai Canal in March after a large pressurized pipe broke.