Metro King County's Brightwater sewage treatment plant tunnel is a project in a very awkward fix. There is a big problem with a contractor and its crippled tunnel boring machine on one of its essential tunnel contracts. All this carries lessons and warnings for the future waterfront tunnel to replace the Alaskan Way Viaduct, and is a critical early test for the new county executive, Dow Constantine.
On February 18, Constantine wrote the King County Council that it was time for decisive action. His fix: Take out of the picture the existing contractor with the failed tunnel-boring machine. Hand over the problem in mid-project to another contractor. Stand up to protect Brightwater ratepayers from costs and delay. Since then, this seemingly simple course correction ran into further problems and plot twists.
Last Wednesday, the Metro King County Council was briefed on the details of the new arrangements. To their credit, the county's Brightwater program managers were brutally honest at the briefing, where the watchword was “making the best of a bad situation.” Councilmembers saw a disturbingly more costly and risky course than Constantine had bullishly anticipated in February. It was expected that Constantine would quickly sign off on the new contract, which only happened over the past weekend. What's up?
The main problem is that the county had little bargaining leverage in switching contractors, and that meant a no-bid and no-guarantees deal to do the remedial work of finishing the excavation of the troubled tunnel section — no fixed price, no firm completion date, not even a firm promise that the work can be done at all. The bottom line for the public: Hold your breath to see how this all comes out. Plan B may be the best way out, but it's not at all a comfortable place for the project or the politicians to be.
So how did the county get itself in this doo-doo? Time for a short history and engineering lesson.
The 13-mile tunnel for the pipes to carry after-treatment wastewater from the new plant near Woodinville to Puget Sound offshore near Point Wells is an indispensable part of the cheerfully named Brightwater project. Three separate contracts were set up to build more or less simultaneously four separate tunnel sections eventually to be linked end-to-end for the run of what is in effect the pipe chase from the plant to the Sound.
Work has gone reasonably well on the two easier sections, the westernmost one inshore from the Sound, and the easternmost section extending from the treatment plant.
However, the third section, boring a tunnel west from Kenmore to Shoreline (Ballinger Way) for a distance of about 3.8 miles, is in deep trouble. For this section King County tapped one of the world’s biggest and most experienced contractors, France’s Vinci Construction. Vinci and its three partners were awarded the job on a competitive bid of $210 million in July 2006. The bid also won for Vinci and its team the second of the tunnel sections, running underground for 2.2 miles immediately east from Kenmore to Bothell.
In each of its two segments Vinci would excavate a 14-foot-diameter tunnel, reaming through the hard-to-mine glacial soils and high-pressure groundwater. The tunnels would be as much as hundreds of feet beneath neighborhoods and streets.
The Vinci segment driven eastward from Kenmore would end at a shaft in Bothell — meeting the first tunnel segment built by another contractor and today completed and connecting with the treatment plant near Woodinville. The Vinci segment driven westward from Kenmore would end at a shaft in Shoreline, meeting the tunnel arriving there from its mining start point on Puget Sound’s shore at Point Wells. That latter segment has been driven successfully by another contractor team headed by the big Michigan contractor, Jay Dee Contractors, and including Seattle’s own Frank Coluccio Construction Co. That section has also gone well, and the Jay Dee/Coluccio boring machine has only 150 feet left to mine to reach its destination in Shoreline.
Both Vinci segments were troubled almost from the outset, two years ago, by a host of obstacles and erratic mining progress. Underground construction characteristically has its challenges, so this was neither surprising nor a reason for panic. The hope in the early going was that progress would improve. But then things turned much worse in May 2009 when evidence emerged that the mining process was causing serious damage to the machines themselves. Both Vinci machines stopped mining for problem assessment and critical repairs.
Vinci’s machine on the Kenmore-to-Bothell segment appears to have been repairable. After months of downtime, Vinci got it back to work in February 2010 with just 4,000 feet left to mine. It’s successfully chewed through a quarter of that in the intervening few weeks.
But the other machine operated by Vinci has now been judged by King County to be best given up for dead. Immobile for almost a year, 300 or so feet below Lake Forest Park, it is badly stuck 10,000 feet from where it started in Kenmore in 2008 and 10,000 feet from where it was supposed to arrive in Shoreline by last month.
All agree that it would be a tricky, expensive, disruptive, and uncertain proposition to try to get this crippled Vinci tunnel-boring machine back into operating condition. The repairs would be technically challenging in any event, but with the machine trapped in a ground-water zone, a work space must be pressurized like a deep sea pressure chamber. That's a very challenging environment for worker safety.
Vinci’s threshold proposal to King County to fix the problem and finish the job for the third segment was that it would cost $98 million and an extra year on its contract completion date. That was a very tough outline of Plan A to recover the job. The county’s frustrated supervisory staff concluded that the true costs in time and money might be even higher and that Vinci couldn’t get back on track quickly enough to avoid significant delays to the entire project.
Enter the new County Executive Constantine, who promptly jumped into the mess. Embracing the staff's negative view of Vinci’s prospects and seizing on bullish assumptions about attractive costs and schedule outcomes by bringing in another contractor to finish the undone mining on the Vinci problem segment, Constantine sent a letter to the council stating that another contractor must be found to complete the excavation of the troubled tunnel segment. He secured the council’s cooperation in paving the way to do so by loosening procurement rules.
So in February the course was set. Full speed ahead to Plan B. Details still to come.
From the council briefing last Wednesday, the exact contract terms and conditions for the Plan B program have become clear, and rather daunting. It is simple in outline. Jay Dee Constructors and Coluccio, the contractors teamed up on the fourth segment Point Wells to Shoreline section, would finish the expected drive of their machine into the shaft at Shoreline. Then they would re-launch their machine pushing it eastward and on past Shoreline into and through the 10,000 un-mined feet in the third segment project. In effect the Jay Dee/Coluccio machine would mine the rest of the third segment from the back door until it reached the location of the crippled westbound Vinci at the halfway point of the segment.
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