NIU VALLEY — Work will begin today on replacing the temporary, above-ground sewer bypass pipe on the Kalaniana'ole Highway median with a new underground pipe.

The project had been delayed for six months while the city tried to reach an agreement with King's Cathedral, landowner of the Niu Valley Shopping Center site, to use a portion of its parking lot. Now all the roadblocks have been removed.

Area residents have said they fear that the longer the black plastic pipe remains above ground along the heavily used Kalaniana'ole Highway, the greater the risk of an incident that would breach the pipe and cause a sewage spill.

The 3,300-foot-long, above-ground bypass sewer line was installed in April 2005 after the existing sewer pipe, installed in 1959, ruptured in the same location three times in one month.

"The community has been concerned that the above-ground pipe could be breached in some manner," said Marty Plotnick, a Niu Valley resident. "It could be by vandalism, a car crash or a natural disaster. It's about time."

Work will start from two areas, near Pu'uikena Drive at Kawaiku'i Beach Park and near Niuiki Circle near the wastewater pump station on Kalaniana'ole Highway. Work will take place from 7 a.m. to 7 p.m.

Ken Kawahara, city Department of Environmental Services spokesman, said there should not be any traffic delays while workers are drilling. Some delays are expected when crews begin to dismantle the above-ground pipe about mid-April.

Kawaiku'i Beach Park will remain open during construction and only the drive-through lane at KFC is affected at the Niu Valley Shopping Center.

Work had been halted since July when the city was refused access to the shopping center. An agreement was reached in November between the church and the city. The Niu Valley Force-Main Replacement Project is expected to cost taxpayers $9 million.

The line collects untreated sewage from Kuli'ou'ou to the east and from as far away as Kalani High School to the west. It carries sewage to the sewage treatment plant at Sand Island.

"We're very glad they're starting because of the potential health hazards with the pipe on top of the ground," said Bob Chuck, chairman of the Kuli'ou'ou/Kalani Iki Neighborhood Board, which includes Niu Valley.

Reach Suzanne Roig at sroig@honoluluadvertiser.com.