COURTESY OF KITV4 NEWS
A staffer worked to clear a massive raw-sewage spill at Sand Island yesterday after a 5-foot-6-inch pipe ruptured.
City deals with
big sewage spillA pipe ruptures near Sand Island,
leaking up to 3.6 million gallons
About 3.6 million gallons of raw sewage may have discharged into Mamala Bay yesterday after a large pipe ruptured 19 feet underground in Sand Island State Recreation Area.
Park workers noticed sewage bubbling up from the ground above the buried pipe at 9 a.m. and reported it to the city, which operates the nearby Sand Island Wastewater Treatment Plant, serving most of metropolitan Honolulu.
The 5-foot-6-inch-diameter pressurized main that broke yesterday transports an average of 40 million gallons a day of raw sewage, under pressure, to the Sand Island plant, said city Environmental Services Director Frank Doyle. Raw sewage is pumped into the pipe from the Ala Moana Pump Station, which serves all of East Honolulu from Ala Moana to Hawaii Kai, Doyle said.
The pipe, which was constructed in 1982, goes under Honolulu Harbor to get to Sand Island, Doyle said.
The leak occurred underground in the state park on the Diamond Head end of Sand Island. When the sewage reached the ground surface, it flowed several yards downhill and into the Fort Armstrong Channel, Doyle said.
Doyle would not estimate the quantity of the spill last night, but confirmed that it is the largest pipe break that the city has ever had.
"This could be very troublesome," he said at 7 p.m. yesterday at the spill site.
The spill could be as much as 3.6 million gallons, based on the average daily volume of sewage in the pipe and the duration of the incident.
Doyle said the media was not informed of the spill until late afternoon because "we spent a good part of the day mobilizing" to solve the problem.
City workers were able to stop sewage from flowing into the broken pipe by 11:15 a.m., by shifting the flow to a second pressurized main that connects the Ala Moana Pumping Station to the Sand Island Plant, Doyle said.
The second pipe has a 4-foot-6-inch diameter and was built in the 1950s, Doyle said.
If it does not rain while repairs are being done, the smaller, older pipe might be able to handle the sewage flow, Doyle said. If it cannot, "there will be another spill," he said.
The entire Sand Island plant normally handles 70 million gallons of sewage a day, but that flow can get as high as 200 million gallons a day during heavy rains.
Doyle said it is not known what caused the rupture, but estimated the work to fix it would take a week. "I hope to do it faster if we're lucky," he said.
Hawaiian Dredging Construction Co. is assisting the city with the repairs.
After the spill, city workers posted signs warning of contaminated water from Point Panic off Kakaako to Keehi Lagoon near the airport and notified the state Department of Health.
A state Department of Health spokeswoman said late yesterday afternoon that the current was moving the spill Ewa-bound and that it would mainly affect Keehi Lagoon.
Keehi Lagoon already had contamination warning signs posted because of contamination from rainwater runoff and sewage spills earlier this week.
Doyle said current detectors would be used today to find which way the spill is moving, and extra water testing would be done in those areas.
After flow through the broken pipe was stopped, city workers using vacuum trucks were able to remove 72,000 gallons of sewage from the pipe by 7 p.m. yesterday, Doyle said.
The vacuuming will continue today until a temporary 10-inch pipe is built from the spill site to the Sand Island plant, he said.
The state Health Department removed Lake Wilson yesterday from its list of waters contaminated by sewage spills in the wake of recent heavy rains.
Still on the list because of water testing results are Pokai Bay in Waianae; Waimalu Stream and Pearl Harbor; Puha Stream, Waimanalo and Bellows beaches; Kawa Stream and Kaneohe Bay; Kaelepulu Stream and Kailua Bay; Kalihi Stream; and Keehi Lagoon.
Yesterday's spill closed Sand Island State Recreation Area. Still closed because of flooding and downed tree branches are the beach side of Ahupuaa o Kahana State Park and Malaekahana State Recreation Area.
