tunnel costsSeattle’s planned deep-bore tunnel could get even more contentious soon. As state engineers flesh out their early cost estimates, a comparable tunneling project has hit another snag. The Seattle Times reports:

The Brightwater sewage-treatment project, which is costing local ratepayers $1.8 billion, is delayed yet again because fixing a damaged tunnel-boring machine stuck deep underground will take months longer than originally thought.

This should be eye-catching because Brightwater’s sewage tunnel construction uses a smaller-scale but very similar tunneling technology to what is planned for the tunnel under downtown Seattle. And the Brightwater tunneling project has encountered numerous problems.

Earlier this year, both machines working on the two “Central Tunnels” were damaged and await repairs underground. The one that was due to be operational by November is, apparently, in worse condition than originally believed. The other is not due to be fixed until December or early 2010.

So the project will be delayed further and the costs will continue to mount:

The delay likely will push completion of the project—originally scheduled for 2010—into 2012, project manager Gunars Sreibers said Tuesday.

It isn’t yet known how much repairs will cost and how much of the cost might be paid by the county, the contractor or the manufacturer of the damaged machines, but, Sreibers said, “We’re in the tens of millions of dollars of money at issue.”

If Seattle’s deep-bore tunnel were to encounter similar problems, it could pose a serious risk for Seattle property taxpayers, who are designated by state legislation to pick up the tab for any cost overruns. The legality of that legislation has been much disputed, but at least one influential legislator has vowed to enforce the provision. (At best, the current funding legislation does not adequately clarify who pays for cost overruns, a potentially serious problem.)

Amplifying the worrisome lessons from Brightwater, the deep-bore tunnel project’s costs were first estimated when the project’s design was considered only 1 percent complete. (Today, the project is considered to be 5 percent designed, but the state has declined to release updated cost estimates until it is 15 percent designed.) None of this is good news, but the Brightwater experience is, unfortunately, consistent with the majority of major tunneling projects undertaken in the area, a topic I covered in a recent report for Sightline, “Cost Overruns For Seattle-area Tunneling Projects.”

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  • But I also have at least a partial defense of the Brightwater project. In the course of writing the report, I looked into the cost estimates for Brightwater in some detail and I concluded that the media has not been entirely fair. For example:

    The existing $1.8 billion tab for the project is roughly double what the Metropolitan King County Council was told when it first approved the project.

    That implied 100 percent cost overrun is technically true, but it’s also misleading. Here’s a fuller description that I included in the report:

    According to newspaper accounts, the projected cost of the total Brightwater project—including a conveyance system for transporting sewage underground, a marine outfall system, and a new wastewater treatment facility—has already exceeded its initial estimates by more than 100 percent. However, this figure is based on an early cost estimate from 1999 of approximately $880 million, which in turn was based on a conceptual design of a wastewater system, without taking into account the actual length and route of the tunnels, the actual cost, or inflation. Cost estimates released in 2004, when the project design was 30 percent complete, established a higher budget baseline that accounted for actual design and siting choices, as well as inflation for materials and labor. Using these updated figures, the total Brightwater project is, at most, 24 percent over budget. [Update 11/20/09: More precisely, I mean that the project’s current projected expenditures are, at most, 24 percent higher than the budget approved as the official baseline in 2004.]

    And the County Council has approved the higher expenditures for the project.

    Additionally, the Brightwater project managers deserve credit for being forthright in a way that some other public agencies are not. The public gets to see annual reports and monthly project updates plus annual quarterly audits. Their community relations officers are informative, engaged, and committed to keeping the public apprised. It’s only because of their diligence and accountability that the media has any realistic view of the project’s difficulties.

    Unfortunately, my experience to date leads me to believe that we should not expect a similar level of openness from officials working on Seattle’s deep-bore tunnel.