Plans for massive wastewater tunnel in Windward Oahu

Published: Oct. 5, 2012 at 2:07 AM HST|Updated: Oct. 5, 2012 at 3:39 AM HST
Email This Link
Share on Pinterest
Share on LinkedIn
Earl Matsukawa (on right)
Earl Matsukawa (on right)
Ron Weinberg
Ron Weinberg
Donna Wong
Donna Wong

KAILUA, OAHU (HawaiiNewsNow) - City officials are pushing for a project in which in a three-mile-long tunnel, about ten to 13 feet in diameter, would be built to carry wastewater from Kaneohe to Kailua.

The tunnel would replace an aging 42-inch force main under Kaneohe Bay Drive. Engineers said it is needed to prevent a disaster similar to the one that happened in Waikiki in 2006, when a similar force main failed.

"There is only one force main that carries all that water, and if anything should happen to the force main, if it goes down like the one in Waikiki, there's the potential for major spillage in Kaneohe Bay until that force main can be repaired," said Earl Matsukawa of the engineering firm Wilson Okomoto Corporation.

Matsukawa and others showed the plans to the Kailua Neighborhood Board Thursday night.

The tunnel would be built beneath the Oneawa Hills area of Kailua, mauka of Kaneohe Bay Drive. The project would include improvements to the Kaneohe Wastewater Pre-Treatment Facility and the Kailua Regional Wastewater Treatment Plant. Engineers said it would cost a total of about $280 million dollars, and take five years to complete.

Some neighborhood board members are still skeptical about the project.

"This is absolute madness," said board member Ron Weinberg. "What is the value of it? What is the value added? Why are you doing this?"

Matsukawa reiterated the risk that a force mail failure would spill sewage into Kaneohe Bay. He also noted that some residents along the tunnel's proposed route are worried about the digging that will be required.

"Many of the concerns are related to the unstable soil conditions in some of the residences, and some of the concerns that vibrations from the tunnel boring machines could aggravate soil conditions and possibly cause property damage," he said.

Questions also were raised about what would be done with the material dug up by the machines, and if they would be trucked along Quarry Road. "Everybody is aware of the very poor condition of the Quarry Road, and if it is decided to take a hundred trucks a day, for years, years, over that road, what is the impact going to be?" asked board member Donna Wong.

Matsukawa said that ultimately, it would be up to the company that eventually gets the contract to do the work.

Public hearings will be held next month on the project, which is estimated at $280 million. Construction is scheduled to begin in November 2013, and take five years to complete.

Copyright 2012 Hawaii News Now. All rights reserved.