NIU VALLEY — Starting today and for at least the next three days, crews will work around the clock on the long-awaited Niu Valley force main project, drilling underground to install a new sewer pipe.

"It was explained by the consultants at our last board meeting that the pipe-pulling must continue uninterrupted," said Bob Chuck, chairman of the Kuli'ou'ou/Kalani Iki Neighborhood Board. "We really appreciate the city action of minimizing interruption of traffic and keeping noise levels to a minimum, keeping the community informed and the speedy action to complete this project."

The new 3,300-foot-long pipe will run under Kalaniana'ole Highway and will be the permanent replacement for the temporary, above-ground sewer bypass that has run atop the highway median since April 2005.

While the city will attempt to do most of the work during the day, there will still be some noise generated at night, said Ken Kawahara, city Department of Environmental Services communications officer.

Traffic, however, will not be affected by this phase of the sewer force main replacement work.

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.

The pipe will be assembled in 250-foot lengths at Kawaiku'i Beach Park and pulled through the underground tunnel toward Niu Valley Shopping Center and the wastewater pump station along Kalaniana'ole Highway.

"Once they start going, they can't really stop," Kawahara said. "The backup beep on the equipment has been turned off and there have been low-noise procedures put in place, with plywood barriers to keep the noise down for the neighbors."

This phase of the job was initially scheduled to begin Feb. 20, Kawahara said.

The next step in the sewer line replacement project is to hook up this section of pipe to the pump station in Niu Valley.

The above-ground bypass sewer line was installed after a sewer pipe installed in 1959 ruptured in the same place three times in one month. Area residents welcome the replacement project, saying they feared that the longer the black plastic pipe remains above ground, the greater the risk of an incident that could break open the pipe and cause a sewage spill.

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 treatment plant at Sand Island.

Reach Suzanne Roig at sroig@honoluluadvertiser.com.