Consultant puts Brightwater tab at $1.8 billion

The Brightwater sewage-treatment plant will cost more than $1.8 billion — and could become even more expensive — a consultant told the Metropolitan King County Council on Wednesday.

R.W. Beck, the consulting firm, said the county's latest estimate of $1.77 billion is an "optimistic" number that probably understates the actual cost. Beck put the total cost at $1.83 billion to $1.86 billion.

The cost — which was under $800 million when King County Executive Ron Sims proposed the plant in 1998 — has become a source of friction between the county and the cities and sewer districts that will send their waste to the new plant.

The county's latest cost estimate was made before recent bidding on an off-site pump station that came in $20 million above budget, said Beck Vice President David Jochim.

The treatment plant itself on Highway 9 north of Woodinville also could become more expensive, Jochim said, because construction-material prices are rising, contractors are extremely busy, several labor unions will negotiate new contracts this summer and contractor-bonding problems are forcing the county to bring in a second general contractor to build the plant.

He said the Wastewater Treatment Division has done "an excellent job" of managing construction of a 14-mile pipeline from the plant to a Puget Sound outfall at Point Wells north of Shoreline. The contingency fund for the pipeline tunnel is sufficient, Jochim said, but the fund wouldn't cover "extraordinary" conditions such as hitting large boulders.

Splitting the plant-construction job between two contractors will slow down part of the job by eight months but isn't expected to delay the scheduled 2010 opening, said Wastewater Treatment Director Christie True.

True said she believes her agency's cost estimates are reasonable but doesn't know whether they are more accurate than Beck's numbers. Costs are hard to predict in the volatile construction market, True said, so her agency won't recommend raising the sewer-capacity charge on new homes based on the Beck estimate.

"We don't want to overcharge people if these costs don't materialize," she said.

Sims, using the county's official cost estimate, has asked the County Council to raise the monthly capacity charge on new homes from $42 this year to $46.25 next year. The monthly rate for existing customers wouldn't change.

County Councilmember Kathy Lambert, R-Redmond, said a Brightwater critic once predicted the cost of the project would rise from $800 million to $2 billion. "I laughed — and now I'm not laughing — because I was told this years ago and thought it was a joke, a bad joke," she said.

Dow Constantine, D-Seattle, chairman of the capital budget committee, said council members will be watching costs closely. "Controlling the cost," he said, "is critical to this project and critical to this council," he said.

Keith Ervin: 206-464-2105 or kervin@seattletimes.com