The city has upheld the low bid from a company that was among three firms bidding to ship some of O'ahu's trash to a Washington state landfill.

The decision means the city might be able to move forward with plans to ship trash out of state, although the ruling is subject to appeal and officials could not say when the program might begin.

The low bid, from Hawaiian Waste Systems, had been challenged by two competing bidders, Off-Island Transfer and Simcoe Environmental Services Inc.

Off-Island and Simcoe had lodged separate protests, asserting that Hawaiian Waste's bid was so low that it "undervalued" the project.

Hawaiian Waste submitted a bid of $99 per ton to ship trash from O'ahu to a landfill in Roosevelt, Wash.

Simcoe bid $184.47 per ton and Off-Island bid $204.21 per ton.

Simcoe and Off-Island yesterday received letters from the city Department of Budget and Fiscal Services that their protests had been rejected.

"The protest was rejected, but I have other options that are available to us and we'll look at all of the decision and move accordingly," Simcoe President David Ross said.

Timothy Hodge, vice president of Hawaiian Waste Systems, did not return calls or an e-mail seeking comment.

The city earlier had estimated it would cost about $75 per ton to ship trash out of state. It now spends $30 per ton to dump it at the Waimanalo Gulch Landfill in Leeward O'ahu.

The losing bidders have seven days to file an appeal with the state Department of Commerce and Consumer Affairs. Once any appeals are resolved, the city can then fully review the low bid and complete the process of awarding the contract, said Kenneth A. Shimizu, deputy director of the city Department of Environmental Services.

"If there is an appeal, the statutory stay that prevents any action towards award of a contract will remain in place for the pendency of the appeal," Shimizu said. "If there is no appeal, then the city can begin the process of awarding a contract."

The city wants to hire a company to ship 106,600 tons of trash per year to a Mainland landfill. That's only about 6 percent of the 1.76 million tons of solid waste generated on O'ahu per year, but proponents of the program say it would help extend the life of the island's main landfill and allow time for the expansion of waste-to-energy technology.

Several Mainland municipalities, including New York City and Anchorage, Alaska, ship trash to remote landfills.

In fact, 10 cities in Alaska ship more than 600,000 tons of trash per year to the same landfill in Roosevelt that would service Hawai'i.

City Council chairman Todd K. Apo, who represents Leeward O'ahu, home to the Waimanalo Gulch Landfill, said he is glad the program is moving forward. He said he hopes that shipping trash out of state, combined with the city's soon-to-be-expanded waste-to-energy incinerator, will eventually negate the need for a landfill on O'ahu.

"I am very pleased that we've gotten the protest resolved and that we're moving forward with the solid waste solution," Apo said. "Obviously I would have liked this to have been done sooner so we could be into shipping already and I think that it could have been done quicker. We need to get to it as fast as possible which has been our message since we budgeted this back in June (2007)."