The bottom of a fiberglass trough inside a clarifier at the Honouliuli Wastewater Treatment Plant in Honolulu failed recently, resulting in less-than-full treatment of nearly 600,000 gallons of wastewater that was discharged from the Barbers Point outfall.
About 12 feet of the bottom of the trough in the No. 4 clarifier cracked and buckled. Approximately 597,524 gallons of partially treated wastewater was discharged before all of the solids in it had settled to the bottom of the clarifier. Much of the discharge was diluted with effluent that had received secondary treatment before it all left the outfall.
The flow into the No. 4 clarifier was stopped and diverted to another clarifier about 45 minutes later.
The outfall is more than 2 miles offshore, at a depth of 200 feet, so the bypass is expected to have negligible effects on the environment.
Source: City and County of Honolulu
