What Could Possibly Go Wrong The Seattle City Council is about to give the state permission to dig the world's largest deep-bore tunnel under downtown Seattle. Here's what the city council doesn't want you to know before they vote.

Greg Stump

You're about to get fucked, Seattle.

On a Monday between now and the middle of August, the Seattle City Council is likely to approve a contract that gives the State of Washington permission to dig a 54-foot-wide tunnel under downtown Seattle. It will be the widest deep-bore tunnel attempted anywhere, ever.

It will cost an estimated $4.2 billion to replace the dilapidated Alaskan Way Viaduct on Seattle's waterfront, making this underground highway the most expensive megaproject in state history. The state has committed up to $2.8 billion, the city has pledged $937 million, and the Port of Seattle is supposed to pay $300 million. The single most expensive element, the tunnel portion itself, will cost about $1.9 billion.

A state law passed in 2009 says Seattle property owners must bear the expense of any cost overruns on the state's project. This is unprecedented. "The cost overruns on a state highway should not be borne by the citizens of Seattle," says state senator Ed Murray, whose district includes Capitol Hill and parts of downtown. "We have never done that to any other jurisdiction in the state." The law also says, unequivocally, that the state won't pay more than $2.8 billion. We simply have no plan for who will pay cost overruns. Under the current rules, if something goes wrong, Seattle taxpayers are on the hook for cost overruns.

Seattle's budget was fucked this year—facing a midyear shortfall of $12 million, the city cut a plan to hire 20 police officers, slashed millions from parks maintenance, let staff go from libraries—and next year's budget projection is even worse. Seattle is facing an estimated $56 million shortfall in 2011, which will require more painful cuts.

But those deficits are nothing compared to what will happen if the state's end of the tunnel goes over budget and Seattle has to find the money to cover the cost overruns. The city's taxpayers could face a $1 billion bill.

But Governor Chris Gregoire and most members of the city council—under city council president Richard Conlin's leadership—insist that there is nothing to worry about and that any public discussion about potential cost overruns is unnecessary. So the city council is on the verge of committing Seattle to this project despite the fact that there are no complete designs yet, despite the fact that there are no bids in from contractors, despite the fact that we don't really know how much it will cost, and despite the fact that we haven't seen the state's environmental impact study.

The governor and the city council's leadership insist there won't be errors, that there won't be cost overruns, that nothing could possibly go wrong.

They're lying to you, Seattle.

Megaprojects of this scale are historically risky and expensive, prone to massive cost overruns. According to an authoritative analysis of 258 massive transportation projects by one of the world's foremost authorities on the subject, Bent Flyvbjerg, a Danish professor at the University of Oxford, 9 out of 10 transportation megaprojects run over their estimates. For tunnel and bridge projects, Flyvbjerg found, "actual costs are on average 34 percent higher than estimated costs."

When it comes to projects like this, things going wrong—things that lead to massive cost overruns—are the rule, not the exception.

So what could possibly go wrong? Lots.

The tunnel-boring machine gets stuck

A massive cylinder with a rotating face covered in blades that gnash away rock and soil, a tunnel-boring machine (TBM) churns everything in its path to paste, which cargo cars then haul to the surface. Each machine is custom-made just for the width of the tunnel it needs to dig. Our TBM will cost around $80 million to build, and, at 56 feet in diameter, it will be the widest TBM ever constructed.

"I've been talking about a 56-foot-wide machine for a long time," says Council Member Mike O'Brien. "Then I looked at a building about five stories tall and thought, 'Holy shit, that is 56 feet. That is one big-ass fucking machine.'"

Our TBM will confront a mixture of sedimentary elements in soft soil, which are the most difficult conditions to penetrate because the loose material tends to cave in behind the machine. So as the machine grinds forward, it must simultaneously create a concrete tunnel lining behind it to hold up the earth. Those concrete slabs narrow the diameter of the hole, preventing the TBM from backing up. Tunneling machines can't travel in reverse. And if the TBM's blades break, the machine can't move forward. It's stuck.

This is not only the most expensive thing that could go wrong, it's also a fairly common thing that goes wrong.

Two TBMs recently got stuck underground in King County. One was 320 feet below an elementary school in Bothell and another is still stuck at the same depth under Lake Forest Park. Both TBMs—each about 15 feet wide—hit loose, abrasive soil and clay that damaged the cutting blades and clogged the mechanisms inside while they were excavating tunnels designed to carry effluent from the Brightwater sewage-treatment facility to Puget Sound. One was immobilized for nine months, and the other hasn't budged in over a year.

"They had problems with sand and grit getting into the rotating part of the tunnel-boring machine face, and it broke down where it was very deep," says Ron Posthuma, assistant director of the King County Department of Transportation, the agency overseeing the project. The $1.8 billion Brightwater project is currently 24 percent over budget. The tunnels were slated to be complete this year but now have been postponed until 2013.

The soil conditions that the Brightwater TBMs encountered—the soil conditions that disabled two of the TBMs—appear to be the same soil conditions underneath downtown Seattle.

"The soils along the alignment are composed of substantial portions of abrasive minerals including quartz grains and quartz-rich rock," reads the state's geotechnical report released in June by the Washington State Department of Transportation (WSDOT). "These granular soils are abrasive and are expected to cause heavy wear on equipment during excavation. There is no tunnel-industry standard applicable to quantifying the abrasivity of a soil and its impact on excavation-equipment longevity and replacement. On other tunneling projects of smaller size TBMs in the Seattle area, substantial wear occurred to the TBMs' cutterheads."

The state foresees other troubling conditions for the biggest TBM ever constructed.

Clay: "The clays present... pose a risk of clogging equipment." Boulders: "Cobbles and boulders will be encountered in all [areas] along the alignment. Boulders within the soil deposits will slow TBM progress and contribute to wear and/or damage to TBM components."

Levent Ozdemir is the author of North American Tunneling, a technical book that examines, among other things, TBMs getting stuck underground due to boulders. "The tunnel boring machines were stuck... a total of 12 times in 40 cases (30 percent overall stuck rate)." Ozdemir notes that "the delay and cost consequences of getting stuck are very high" in tunnels deeper than 50 feet and in those that go beneath the water table. Seattle's tunnel will go about 120 feet deep and will go below the water table near Pioneer Square. Ozdemir cites an example of a TBM that got stuck underground near Seattle when the machine digging the Snohomish River undercrossing got stuck.

Tunnel Talk, a website that tracks tunneling projects, cites a case in the Swiss Alps. The TBM digging the Gotthard Base Tunnel got stuck in 2005 when it hit unstable, soft soils—similar to the soils under downtown Seattle—and the tunnel collapsed in front of the cutting blades.

So what happens if a TBM gets stuck under downtown Seattle? A TBM can't be backed up, and it can't be dismantled underground. It can only be dug out.

"I am envisioning this scenario where a 56-foot boring machine gets stuck under the Federal Building and you can't dig it out because it is under the building," says O'Brien.

If the TBM does stall under the Federal Building—or any one of the 390 downtown buildings it will pass under or near—a five-story-wide chasm would have to be opened in a downtown street to the depth of the stalled machine. Then a tunnel would have to be dug sideways to the stalled machine. Then the soil above this second tunnel would have to be shored up, to protect the buildings above, and only then could the broken TBM be lifted out and a new TBM lowered down into the hole—a new machine that could also break down.

Our plan to deal with a broken machine is inadequate

"In this worst-case scenario," state consultants say in a document assessing risk released last October, "the TBM will fail and be rendered useless, resulting in the project contractor abandoning the project and necessitating a new contractor to be found." The state requires all of the bidders to have bonds, essentially insurance, which cover costs if they abandon the job.

But the bonds on this project may not cover those costs. Until a few years ago, the rule was that companies had to be bonded to the full amount of their contract—which makes sense. In addition to the cost of dealing with an abandoned machine and finishing a project, the bond must also pay for a new contractor who will charge more to complete the job (after all, the previous business couldn't make it work for the amount of money the state was paying). However, the state legislature suspended its own bonding rules for five years in 2009—the time frame that our tunnel goes out to bid—and now only requires that a project be bonded up to $500 million. The tunneling portion of the contract examined for bonding purposes is $1.2 billion, more than double the bonding requirement.

This has a major advantage for the state: Bids come in lower because the contractors don't have to include the cost of more expensive bonds.

This has a major disadvantage for the city: If the bonds don't cover the cost of the TBM's failure, there's not enough money to pay for the project.

"It's not the state's risk, because they want the city to take on cost overruns," says Mayor Mike McGinn. "They have been telling us they have been doing everything they can to reduce risk, but they're doing what they can with the bond requirement to put risk of overrun on Seattle taxpayers."

The state claims it has addressed these concerns by requiring two sets of consultants to determine what the worst-case scenario would cost and whether $500 million would cover it. And what do you know? The state says it will work out just fine. Paula Hammond, the state's secretary of transportation, wrote in a letter to the office of financial management last November that "the state's maximum exposure to loss is $467 million, so a performance bond set at $500 million is reasonable."

But not everyone is convinced that $500 million will cover it.

"All of the assumptions we picked are rosy," says O'Brien. For example, the state estimates that retrieving a stuck machine could cost up to 10 percent of the remaining project cost, and inserting a new one could cost another 10 percent (20 percent total). But then—in outlining the "worst-case scenario"—the state only figures in 3 percent cost total for both of them. O'Brien says, "We round in our favor every time."

The ground caves in

Because we're dealing with loose soil, there is a chance that the ground could cave in behind the tunneling machine. This isn't as likely as a TBM breaking down, but it can and does happen. In fact, it happened last year north of Seattle on the Brightwater project. A 30-foot-wide, 15-foot-deep sinkhole swallowed up Pauline Chihara's driveway in Kenmore. Tom and Jan Glithero, who live above another one of the Brightwater tunnels in Bothell, found cracks in the brickwork in their home, their patio, and their driveway—all attributed to settling caused by the tunnel's excavation underneath the couple's home.

In 2003, a sinkhole opened up near a tunnel being bored in London, and people had to evacuate their homes. On March 3, 2009, a tunnel collapsed in Cologne, consuming the city's historical archives building and killing two people.

"I've seen overexcavations open up 300-meter tall caverns over the TBM, and all that dirt fell right on the machine," John Turner, chief engineer of TBM builder the Robbins Company, told Machine Design in 2001. "And the cave-in can go all the way to the surface, which is a real disaster." In the same article, Marco Giorelli, a product manager for another TBM builder, said, "Overexcavations can be particularly harmful in cities... They lead to settlement, and it doesn't take much settling to damage buildings."

The loose soil in downtown Seattle doesn't have driveways or single-family homes sitting on top of it. It has the historic buildings in Pioneer Square, new condo towers and hotels, and the tallest buildings in the state.

Not all the money will come through

Of the total project cost of $4.2 billion, about $937 million is Seattle's responsibility (to rebuild the seawall and move utilities) and $3.1 billion is the state's responsibility. Most of the state's money is coming from gas taxes. But the state is relying on two tenuous funding sources to come up with $700 million of its share: the Port of Seattle and bonds for future tolling of the tunnel.

The Port of Seattle is supposed to chip in $300 million toward the project, but the state's agreement with the port is nonbinding. The port passed a resolution in April that says, "To the extent feasible and authorized by the port commission," it will come up with the money, as long as it doesn't interfere with the port's other responsibilities. The port is partly funded by property taxes, which have plummeted as property values have dropped in the recession.

"The commission hasn't specified the source of funds for our contribution," says Port of Seattle spokeswoman Charla Skaggs. "A key component will be the tax levy, but commissioners have directed staff to limit the need for levy resources for the contribution as much as possible."

And if the port doesn't feel like coming through with the money or it's strained to meet its other obligations, it doesn't have to pay anything.

The tolling revenue, which is budgeted to generate up to $400 million, is slightly more secure. The state plans to issue bonds (based on future tolls) that Ron Paananen, who is overseeing the tunnel project, says will likely end up producing $385 million.

Although promising, the toll money raises an obvious question: Who pays the other $15 million? The state? Seattle? Nobody knows.

There isn't enough money set aside for cost overruns

The state and some city council members have repeatedly trumpeted $415 million set aside to cover cost overruns. That figure sounds good. The riskiest part of the viaduct-replacement project is the $1.9 billion for the tunnel. And the actual tunnel excavation itself, the riskiest part of the tunnel, represents just $350 million of the project's total cost. So the amount set aside should protect us, right?

Nope.

It turns out that more than a third of that money is actually set aside to cover the costs of inflation, leaving just $258 million to cover cost overruns. That would leave enough to cover cost overruns of about 13 percent for the price of the tunnel—far below the 34 percent average on this sort of tunneling project. But it gets worse: The state's obligation is for about $3 billion of work. So the money set aside for cost overruns represents less than 10 percent of the state's total project cost.

And it's not just the tunnel that could go over budget.

The downtown bus tunnel, completed in 1990, ran 56 percent over its initial projected budget, according to a report last November from the Sightline Institute. Posthuma, assistant director of King County's transportation department, points out that the tunnel itself—a very different sort of tunnel—came in 25 percent under the final estimates when it went out to bid. So what increased the costs of the project overall?

"It was partly the station finishes," he says, "and also the surface street finishes," among other expenses.

This project is much more than just a tunnel—one that involves a lot of "street finishes." Huge swaths of downtown Seattle and the waterfront are going to be rebuilt—and a lot could go wrong, and a lot of other parts of the project could come in over budget. WSDOT must pay for a 13-lane-wide tunnel portal on the south end, reconnecting the street grid on the north end, rebuilding part of the downtown waterfront where the Alaskan Way Viaduct now stands, as well as some utility repairs and more. Those are essentially road projects that, while less risky than tunnels, frequently come in over budget. Returning to Flyvbjerg's report, the one that examined 258 megaprojects, when it comes to road projects, "actual costs are on average 20 percent higher than estimated costs."

The light-rail tunnel under Beacon Hill also ran over budget by 30 percent (from an estimated to $238.6 million to $309 million). Many of those costs had nothing to do with the tunnel. They were attributed to station construction and elevators.

There simply isn't enough money set aside to cover "average" cost overruns, to say nothing of the catastrophic cost overruns we could face if a TBM gets stuck under downtown Seattle—or if a hole swallows a downtown office building.

Lots of other things go wrong

The ground could settle in unpredictable ways, a sewage line could break, bidders could drop out and the remaining bidders could gouge the state, there could be another earthquake, the bids could come in at a price higher than the amount the state has agreed to pay—and the project could get tied up in court. In fact, Elizabeth Campbell, a Magnolia resident and head of the group Seattle Citizens Against the Tunnel, is determined to file a lawsuit as soon as the council approves the contract.

While construction unions are backing this project, labor disputes could also get in the way. In Vancouver, BC, Bilfinger Berger won a $100 million contract to build tunnels for a water filtration system. Work began in 2004 but stopped in 2008, when falling rock injured several workers. Metro Vancouver terminated the contract in May of 2008, claiming that Bilfinger Berger had refused to resume work on the tunnel even though safety concerns had been addressed; the company claimed the stop-work order was never lifted. The upshot: A new company got the contract, but, once the tunnel opens later this year, it will cost an estimated $400 million. That's four times its bid price.

The people who say, "Nothing will go wrong" are often wrong (or they're lying)

The top reason why transportation projects run over budget is because people who have the most to gain—developers bidding on contracts, labor unions worried about jobs, state agencies with reputations on the line, politicians looking for campaign contributions, construction unions that make campaign contributions—have an incentive to lie about risks. Once the project is under way, it is hard to stop, even if costs skyrocket. The Big Dig in Boston started with an estimate of $2.8 billion, which grew to a final cost of $14.6 billion, and is expected to cost $22 billion with interest when it's finally paid off in 2038.

"The use of deception and lying as tactics in power struggles aimed at getting projects started and at making a profit appear to best explain why costs are highly and systematically underestimated in transportation infrastructure projects," say Flyvbjerg, Mette Skamris Holm, and Søren Buhl in a report from 2002. "Legislators, administrators, investors, media representatives, and members of the public who value honest numbers should not trust cost estimates and cost benefit analyses produced by project promoters."

In this case, the "project promoters" trying to muscle through the tunnel contract are Governor Gregoire and certain members of the Seattle City Council. And something else that undermines the credibility of tunnel backers: They are running from this debate. Mayor McGinn offered to debate council president Conlin about the tunnel and cost overruns, Town Hall Seattle offered to host the debate, and KING 5 was anxious to air it. Conlin refused to debate the mayor. After Conlin refused, the offer was extended to Council Member Sally Bagshaw, who made her support for the tunnel a big issue in her campaign for city council, but she also refused. Likewise, Council Member Tom Rasmussen, chair of the council's transportation committee, refused to debate the mayor.

For his part, Rasmussen says that the city has consultants who will look at various potential risks—such as those associated with relocating utility lines, soil conditions, and insurance, among other things—and make sure the city isn't exposed to undue liability.

"There will be no sugarcoating, no rose-colored glasses," Rasmussen says. "We have to know all the risks and make sure all of them are honestly portrayed and explained to us... I don't want people to think that we want this so badly that we are ignoring any red flags."

The mayor's office characterizes the work of the council's consultants largely as nipping at the edges of bigger problems while ignoring some of the project's larger inherent risks—like constructing the widest deep-bore tunnel in history. In June, McGinn hired an independent consultant, tunneling risk expert Thom Neff, to look at the risk.

"I think it is important that there is at least one expert who wasn't hired by tunnel cheerleaders," McGinn says.

All of the city's consultants and the state's engineers are—almost certainly—doing their very best. But every megaproject that ever went over budget had plenty of diligent consultants doing their very best. The issue here isn't the number of consultants picking this project apart. It's whether the city council is going to approve a contract that financially shackles Seattle taxpayers to a state project that the city won't have any control over. Right now, the city and state don't have a plan for dealing with cost overruns. And the only thing on paper right now unequivocally states Seattle taxpayers must pay for all cost overruns.

But requiring a change to that state law before approving the contract, as McGinn has suggested, "is a way of definitely killing the project," Rasmussen says.

* * *

Maybe the project deserves to die

"If we were trying to cure cancer, we could say, 'Go ahead, it's worth the money,'" says Cary Moon, director of the People's Waterfront Coalition. "But for a two-mile-long stretch of what will be a not-very-well-used road—is it worth this level of significant risk and money?"

The numbers for the tunnel—once it's completed—don't look very good. The current Alaskan Way Viaduct carries about 110,000 cars a day. Once the tunnel opens in 2015, the number of cars using Highway 99 through downtown Seattle will drop to 46,000 cars a day, according to a tolling study by the state. That means 64,000 additional vehicles a day will be forced onto downtown surface roads, along the waterfront, and onto I-5. Why? Cars that want to go downtown can't use the tunnel because it will have no downtown exits. And people who don't want to pay the toll won't use it. During peak hours, the trip will be $4 one way and $3.50 the other. That's $7.50 to use the tunnel. Many of the cars diverted from Highway 99 will pour into Pioneer Square instead, further clogging that neighborhood's already traffic-clogged streets.

"There is a pretty significant amount of traffic diversion" with the tunnel, admits Ron Paananen, who is overseeing the tunnel project for WSDOT.

Ironically, many tunnel supporters have insisted that the tunnel would benefit blue-collar workers going to their jobs. But blue-collar workers are the least willing and least able to pay $7.50 to use the tunnel. They will join the majority of drivers who pour onto surface streets.

And I know this sounds wonky, but the state hasn't finished something called an environmental impact statement, a document that may reveal that this project—a project that is already under way, if council president Conlin and Governor Gregoire prevail—shouldn't be built at all.

Bear with me: An environmental impact study isn't just about how many birds will die. It is the definitive analysis of the impacts of the project. That study, which will come out in draft form for public comment this fall, will compare the tunnel to rebuilding an elevated highway or a cut-and-cover-tunnel option. State law requires us to complete this study before the state commits to one option. But the state, by putting the project out to bid and entering into an agreement with Seattle, is committing to one of the options without knowing if it has any major ramifications. (Remember that lawsuit? Sounds like they may have a case, huh?)

So even if everything goes right and there aren't any cost overruns, we know the project is hugely expensive, forces more than half of the traffic now on the viaduct onto surface streets, destroys the (already battered) quality of life in Pioneer Square, and directs money that could go toward making downtown streets better for transit into building yet another freeway. And if anything should go wrong, the city could be bankrupted.

The question here shouldn't be whether the mayor has a "secret agenda" to kill the tunnel. The question should be why every elected official at City Hall doesn't also have one.

What happens next

The city council will decide the conditions of our contract with the state within the next six weeks. By approving it, the city gives the state permission to begin construction. Seattle has basically no leverage after construction begins.

Most of the city council is arguing that we don't need to fix the state law, we don't need to see bids, we don't need to see the state's environmental impact statement, we don't need to increase the bonds for the company doing the tunneling, and we don't need any provisions that allow Seattle to back out if, say, bids show the tunnel will cost too much. They also say that the time for debate has passed.

But Seattle has never debated this issue. (When Seattle voted on a slightly different tunnel in 2007, we rejected it.) There was certainly never a public debate about the terms of this contract, and Conlin has done all he can to avoid having that debate now. Conlin has also attempted—with an assist from the Seattle Times—to paint the mayor as an irresponsible obstructionist when, in point of fact, the mayor appears to be the only person at City Hall looking out for Seattle taxpayers.

"The bottom line for the planning process," say Thom Neff (McGinn's outside expert) and Gary Brierly in an article titled "Bullshit as Applied to Tunneling Projects" in the April issue of TBM: Tunnel Business Magazine, "is to let the games begin: debate, argue, make your claims and counterclaims, and do everything possible to come up with the best possible project." The authors, who are both authorities on the runaway costs of tunnels, warn that "errors in the planning effort can lead to... inadequate financing, unreasonable debt for the local citizens and agencies, and, in rare cases, a tunnel that should never have been built."

On June 28, the mayor gave a draft of the contract ordinance to the city council that says the city won't give permission to build a deep-bore tunnel under downtown until the state legislature removes the provision that caps state spending on the project and says Seattle must pay for cost overruns. The city council disregarded the mayor's proposal as a delay tactic. Laura Lockard, spokeswoman for the city council, says the mayor's proposal was "theater."

The council is expected to remove the mayor's provision, the mayor has vowed to veto any tunneling bill that doesn't contain a provision that protects Seattle taxpayers, and the council is expected to attempt an override the mayor's veto.

But if the city council was serious about representing the citizens of Seattle, it wouldn't just leave McGinn's provision in—it would add two more.

Council Member O'Brien is pushing an amendment that would "reserve an option to void the agreement" if the bids come in too high or the environmental impact study shows that the tunnel would have enormous ramifications.

"You want me to sign a contract that is our last leverage point and you won't tell me what it says until later?" O'Brien asks about the current version of the bill. He says committing Seattle to the tunnel before impact studies are complete would be a "mockery" of the process.

Rasmussen, chair of the council's transportation committee, says he would support O'Brien's plan to let the city opt out if bids "come in way over" the state's spending cap. But he dismisses the idea of voiding a contract simply because the impact study shows the tunnel wouldn't solve transportation problems. (Think about that: The chair of city council's transportation committee is willing to spend a billion of your tax dollars—and potentially hundreds of millions more—on a transportation project that doesn't solve transportation problems.)

Meanwhile, Council Member Nick Licata is pushing a provision that would reserve $290 million of the project budget for tearing down the Alaskan Way Viaduct and rebuilding the waterfront—and to complete the project regardless of cost. That sort of provision, Licata says, would give the city "critical assurance that the state won't spend our money on the tunnel when they should spend it on removing the Alaskan Way Viaduct and providing the new street on the waterfront."

All three amendments—making the state pay for overruns, letting Seattle opt out if the project will cost too much or if research in the next six months shows the project has major negative ramifications, and setting money aside for the waterfront improvements—should be approved. None of them kill the project, as some members of the city council would have you believe. They simply would protect Seattle's interests—which is the Seattle City Council's job.

Would the state remove the spending cap and accept responsibility for cost overruns?

"I think there is support in the senate to reform that provision," says state senator Ed Murray. "I think the mayor has a valid point. The legislature needs to get that fixed. Seattle should be treated like any other jurisdiction, it should not be required to pay cost overruns on the state highway."

Murray says he would sponsor legislation to make the city and state share the burden of cost overruns equitably. The question is whether the state house would pass it. Speaker Frank Chopp says he can't speculate. The most powerful person in the house, Chopp represents the 43rd District—comprising the central city, the same district that Murray represents—and his Seattle constituents should press him for a deal that is fair to Seattle.

While there may be support in the legislature next year to remove the language that makes Seattle pay hypothetical cost overruns, that support could disappear if we wait until cost overruns do actually occur.

That last scenario is exactly what Council Member O'Brien—a former chief financial officer at a law firm—fears most. "I think Seattle will make a legal argument that the city is not liable. But that's not to say that there aren't ways the legislature can make Seattle pay. It is easy to imagine a scenario in which cost overruns occur and the legislature wants to put it on Seattle. The legislature says, 'We passed a law that says Seattle has to pay, so now you have to pay.'"

State law specifically states that any costs beyond $2.8 billion on "shall be borne by property owners in the Seattle area who benefit from replacement of the existing viaduct with the deep bore tunnel." Council president Conlin wrote on his blog in May that state law "says nothing about the City [of Seattle], but instead makes a legally meaningless reference to property owners."

Attorney General Rob McKenna disagrees.

"Once [a law] is adopted," McKenna said on KUOW last fall, "it's our job to defend it. A law which is adopted by the legislature is presumptively constitutional."

There is a case to be made that Seattle isn't "on the hook" for cost overruns. "The legislature can't just tax a group of people in a geographic area," says City Attorney Pete Holmes. "This is a state highway, and the state is responsible for all the costs." If the state exceeds costs in any contracts, he says, "they could send us a bill. They can't make us pay it."

The legislature would have to take further action—but that's something some lawmakers say they may do—to force Seattle to pay.

"I will try my best, as will a number of other legislators, to live up to the law that we passed that held Seattle to these cost overruns—that is all I can say," says state senator Jim Kastama of the legislative district that encompasses Puyallup. "There is a track record of tunnels not coming in on budget, and it is not just me saying that [we're going to make Seattle pay], it is the general consensus of the legislature.

"That amendment is real," Kastama continues. "People who think it is window dressing, they don't understand the level of support for that amendment in the legislature."

As for city council members and state elected officials—including the governor—who insist that Seattle won't have to pay, regardless of the law as currently written, Kastama urges Seattle taxpayers not to believe them.

"The people who are giving you these promises aren't going to be here in a few years," Kastama says. "The people who are saying there will be no cost overruns won't be in office when it's time to be held accountable."

Conlin, who was just elected to his fourth term on the city council, will probably be long retired—along with Rasmussen, Bagshaw, and Gregoire—when the whole project is complete in 2018 and Seattle may have to grapple with a bill for a tunnel it didn't need.

"We have a $56 million budget shortfall right now," says O'Brien. "If we have to come up with another $50 million, $100 million, or a half billion dollars, it would be devastating to our city. I know fellow city council members don't want that outcome, but I have been frustrated that they have not been willing to engage in a more robust dialogue to prevent that outcome."

This story has been updated since its original publication.