Rain-driven sewer spills
prompt city evaluation

A sewage spill near Hawaii Loa Ridge -- which sent about 100,000 gallons of waste water into nearby waterways and roads -- was apparently caused when construction materials got caught in a 12-inch sewer line, city officials said yesterday.

Crews found 3- and 4-foot-long pieces of wood in the line, and officials are investigating where the debris may have come from and how it got into a nearby manhole.

Meanwhile, this weekend's heavy rains are being blamed for five other sewage spills on Oahu, and city engineers are expected to study what can be done to prevent similar spills during future downpours.

"Our system was just being overtaxed with the amount of rainfall," said Eric Takamura, acting director of the city's Environmental Services Department.

"Some of the systems are getting on the older side."

He said there are plans to look at existing improvement projects and decide whether more work is needed.

Waste-water spills reported after Saturday's heavy rains were:

» At Kawaihae Street and May Way in Hawaii Kai, where 30,000 gallons of raw sewage poured out of a manhole. The spill was reported about 4:20 p.m. by a crew from Hawaii-American Water Co., which operates the Hawaii Kai sewage system.

» At 5703-L Kalanianaole Highway, where about 10,000 gallons flowed out of a manhole from 1 to 7 p.m.

» At the Navy Marine Golf Course in Aliamanu, where about 7,000 gallons of untreated sewage overflowed from a manhole. The spill was reported at 2:50 p.m. and ended more than two hours later. Officials said the waste water was confined to the driving range, and cleanup began yesterday.

» At the Aliamanu No. 2 Wastewater Pumping Station on Salt Lake Boulevard, where between 5,000 and 7,000 gallons of untreated waste water spilled from a "wetwell."

The two-hour spill started at 2:55 p.m., and most of the waste water ran into a storm drain system that discharges into Salt Lake.

» At the Waimanalo Wastewater Treatment Plant on Kalanianaole Highway, where about 1,000 gallons of partially treated waste water spilled from overflowing injection wells.

Signs have been posted at waterways affected by the spill, and state officials are expected to test for contamination.