Facing yet another federal lawsuit over problems with Honolulu's crumbling sewer system, the city is poised to make a $300 million promise to replace or upgrade six major pipes.

The work is among dozens of sewer projects the city is already planning. But the new agreement would tie the work to a court order meant to ensure that the city follows through, according to officials familiar with the deal.

The agreement — called a stipulated order — would involve the city, U.S. Environmental Protection Agency, U.S. Justice Department and state Health Department.

The order is to be filed in U.S. District Court along with a lawsuit the EPA is preparing against the city, according to City Council members who were briefed privately by attorneys yesterday.

The EPA would agree to not pursue penalties through the suit if the city complies with the agreement, Councilman Charles Djou said.

The pipes targeted in the deal are "force mains" — major pressurized lines that send sewage to treatment plants — similar to the one that ruptured in Waikiki last year and prompted the city to divert 48 million gallons of raw sewage into the Ala Wai Canal.

The disaster forced the temporary closure of world-famous Waikiki beaches and gave Honolulu's tourist industry an embarrassing black eye.

The pending deal calls for work on some of the sewer projects to begin over the next year, and includes benchmarks for their completion, Djou said.

The city will not be required to spend a specific amount, but officials estimate the work will cost $300 million, he said.

As part of the agreement, the EPA will not fine the city for the Waikiki spill, Djou said.

Others said the deal also will require redundant pipes in some areas to handle the sewage flow if a main pipe breaks. As four pipes are replaced, the old pipes will be retained to provide the redundancy. Sections of two other force mains will be replaced or refurbished.

The city has installed a temporary bypass line along the Ala Wai to carry any overflow sewage. And a permanent bypass is scheduled to be completed this fall.

The two pipes are expected to cost a total of $50 million, and the city plans to spend more than $22 million more to replace the force main.

Other force mains the city had already planned to replace are in 'Ahuimanu, Aliamanu, Kane'ohe, Lualualei, Niu Valley and Ala Moana.

STILL MORE WORK TO DO

City attorneys and other officials declined to disclose details of the deal because it is pending approval by the council, which has tentatively scheduled a vote for May 2.

"On one hand, I'm happy we seem to have reached a settlement," Djou said. "Unfortunately, it's only the beginning of the ordeal the city is facing with its decrepit infrastructure."

Meanwhile, the city is contending with two other federal lawsuits over its sewage problems, and may also be required to complete expensive upgrades of two major sewage treatment plants.

A 1994 suit by the EPA resulted in a consent decree that required a range of sewer system improvements, and a 2004 suit by the Sierra Club environmental group is still pending.

A federal judge agreed Monday to reconsider an earlier decision denying an immediate ruling on portions of the 2004 suit, which allege more than 14,000 violations of the federal Clean Water Act.

The alleged violations stem from the city's federal permit to operate the Sand Island Wastewater Treatment Plant, and its failure to install a disinfection facility there by a 2002 deadline.

The city had argued that the delayed project should count as a single violation, but the court ruled that a permit violation occurred on every day the project was late.

The court declined to immediately rule on the total number of permit violations or the penalties the city should face, however.

RULING CONTESTED

The disinfection facility has been completed and is undergoing a period of test runs, a city spokesman said.

A Sierra Club attorney said the group is also awaiting a ruling on its request to become a party to the consent decree in the 1994 suit.

The EPA said last month that the city's Honouliuli Wastewater Treatment Plant does not meet national water quality standards and will require major upgrades, which the city estimated would cost $400 million.

The city is contesting that tentative ruling, but is bracing for a similar finding at the Sand Island plant, the city's largest. Upgrading both plants could cost $1.2 billion, according to Mayor Mufi Hannemann. An initial EPA decision on the Sand Island plant is expected in October.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.