The city is gearing up for a $48 million sewer rehabilitation project set to start next year that will stretch from Kalihi to Nu'uanu and replace or repair 25 miles of pipeline by December 2009.

The project is by far the most ambitious sewer rehabilitation project the city has ever undertaken in terms of the size of the construction area and miles of line to be replaced or repaired, officials said.

The work, which will coincide with two other sewer rehabilitation projects in Kalihi, is expected to spur traffic headaches on everything from major thoroughfares to narrow, private lanes. And in places, crews will even have to dig up some backyards to get at aging sewer lines, city officials said.

"Obviously, there's going to have to be a lot of public outreach," said Craig Nishimura, deputy director of the city Design and Construction Department. "It's a rather large project."

Though the city is in the midst of a slew of sewer and road repaving projects, it is rare for one project to affect so many streets at once over such a large area. And it has been at least a decade, officials said, since the city had to go into backyards to replace sewer pipes.

The city says the work is not only overdue, but mandated.

Under a federal Environmental Protection Agency order, the city has until the end of 2009 to fix a host of badly deteriorated sewer lines prone to breaks in Kalihi and Nu'uanu. The city has said some of the sewer lines are in such bad shape they could be leaking.

The order was issued in 2003, and said the work was needed to stop wastewater spills into Kalihi and Nu'uanu streams. From 1998 to 2003, the order said, there were 33 such spills.

Officials said the mandate forced the city to do all the rehabilitation work at once. The size of the project will present unique problems, ranging from notifying property owners to coming up with traffic plans for busy thoroughfares.

Officials hope to head off traffic backups by advertising street closures and asking people to choose other routes. They'll also start notifying homeowners affected by the sewer work soon.

The project comes as the city is putting strong emphasis on repairing sewer infrastructure, and is moving forward with a 20-year sewer rehabilitation plan for O'ahu, which the EPA approved in 2000.

In 2007 and 2008 alone, the city budgeted more than $433 million for sewer repairs. To help pay for the improvements, the city will increase sewer fees over the next four years.

"We're trying to fix so many things at once," said Eldon Franklin, wastewater division chief at the city Department of Design and Construction. He asked residents to "be patient."

Contractors are bidding for the $48 million Kalihi project this month, and construction is set to start in April. In addition, the city will kick off two other sewer repair projects in Kalihi next year.

An $8 million project to repair and replace sewer lines on Houghtailing Street in Kalihi, and a $7 million project to reconstruct lines in Kalihi Valley also will mean lane closures and congestion.

NO COST OVERRUNS

Nishimura said he does not expect cost overruns on the projects, since many of the pipes involved are small- to mid-sized.

Unexpected problems on some sewer projects have resulted in significantly higher costs than originally anticipated, though. For example, the recently completed Kalaheo Avenue sewer project in Kailua was supposed to take three years and cost $36 million but ended up taking seven years and costing $58.5 million.

Ken Harding, Kalihi-Palama Neighborhood Board secretary, asked why residents haven't yet heard about all the Kalihi projects and said the city needs to get the word out on the work early.

"It alarms me that they're going to be disrupting the traffic on such a long-term basis with so little warning or planning," he said.

Work on the Kalihi/Nu'uanu rehabilitation project will close lanes on several well-used roads, including Middle Street, Vineyard Boulevard, Wilder Avenue and Nu'uanu Avenue.

Construction will largely be done during the day.

At least two neighborhood boards have been alerted about the project, but Nishimura said the city will step up outreach closer to the start date with community presentations and possibly by putting up a Web site.

He said the property owners whose backyards will need to be dug up will be notified of the work by contractors. The city did not have figures for how many homeowners will be affected.

The project to repair or replace pipes ranging from 50 to 100 years old has been split up into nine contracts so that small and midsize companies can bid for the work. Most of the pipes that need to be replaced are made of terra cotta and are undersized.

The bulk are between 6 and 10 inches in circumference, officials said, but some on the thoroughfares are 18 inches around.

The city said the pipes in worst shape have sustained small cracks over the years as the ground has settled. The cracks not only increase the chance of leaks, but main breaks are more common as rain and debris can easily enter the lines, overloading them.

A survey last year of the more than 34 miles of sewer pipeline in Kalihi and Nu'uanu showed about 75 percent were in poor condition.

The project will replace about 10 miles of line and repair about 15 miles. The repaired lines, along with other pipes, will have to be replaced sometime in the near future.

Paula Kurashige, chairwoman of the Nu'uanu/Punchbowl Neighborhood Board, said it's no surprise sewer lines in the area are inadequate. She said residents have been telling the city for years that something needs to be done, especially as more people move in.

"People continue developing in this area without having a better infrastructure in place," she said. "Unless the sewer system is updated, no more development should come into this area."

Now, she said, the city needs to focus on repairing aging water lines in the district, repaving roads and installing sidewalks.

Reach Mary Vorsino at mvorsino@honoluluadvertiser.com.