Big Dig tunnels spring 237 leaks
Costs climb as state plugs serious spots Engineers say fixes could go on for years
Despite repeated assurances that it had Big Dig leaks under control, the Turnpike Authority has allowed the number of leaks to explode in the last two years and has been forced to launch a fresh effort to plug hundreds of trouble spots, according to an analysis of Big Dig records.
A massive effort by Big Dig contractor Bechtel/Parsons Brinckerhoff reduced the number of the most serious leaks near the tunnel roof from more than 800 in March 2005 to just three eight months later, according to Bechtel/Parsons Brinckerhoff records posted on the turnpike's website. But the state sharply curtailed efforts to seal leaks when it took over maintenance in 2006, and the number of serious leaks going unchecked rose to 237 last month, according to interviews and turnpike records.
The resurgence suggests that water infiltration could require attention indefinitely on the $15 billion project - and is not the temporary glitch originally asserted by contractors and the state. The new leaks raise serious questions among some officials and engineers about maintenance costs, repair schedules, and premature corrosion of steel reinforcements in the walls.
Edward Ginsburg, a retired judge charged in 2003 with seeking refunds from contractors for shoddy work, recalled the many assurances he received in 2004 from both state and Bechtel/Parsons Brinckerhoff personnel that leaks would be taken care of and quickly cease to be an issue.
"They were furious when we raised it as an issue, and they said it would all be fine," he said. "Well, it isn't fine. It's the same basic situation."
Turnpike officials emphasized the structural integrity of the tunnels is uncompromised, and that a serious breakdown could happen only after 25 years of continuous water damage. The officials said they took over a leak-riddled tunnel and have launched a major effort to get the problem under control. But state officials acknowledged there is already surface rusting on 10 percent of the massive steel girders in the ceiling.
Overall, a recent engineering report shows there are a total of 670 Big Dig leaks, of which the 237 are in a category considered the most serious.
"I don't like to see 670 leaks - that has to be erased," said Robert Rooney, deputy secretary for public works, who assumed his state job in July.
Rooney said his boss, Transportation Secretary Bernard Cohen, ordered the Turnpike Authority late last year to assign one engineer to work full time on the leaks. He also ordered the authority to increase the number of contractor crews fighting leaks from just one to five or six.
Rooney said the number of leaks should be reduced to no more than a couple of dozen by the end of 2008.
"We don't want to have to rebuild those tunnels because of damage," he said. "Proper maintenance can extend its life indefinitely."
If girders were degraded and reconstruction required, Big Dig managers - as well as drivers - would face a logistical nightmare. With the old elevated Central Artery torn down, there is no simple alternative route for getting traffic through the city.
In a statement, Alan LeBovidge, the turnpike's new executive director, said the agency "inherited a mega-project riddled with problems" and called Bechtel/Parson Brinckerhoff's accounting of its leak reductions in 2004 and 2005 questionable.
A spokesman for Bechtel/Parsons Brinckerhoff declined to comment. Bechtel/Parsons Brinckerhoff is currently in negotiations with Attorney General Martha Coakley over a settlement that would reimburse taxpayers for leaks and other deficiencies. Coakley's office also declined to comment.
Bechtel/Parsons Brinckerhoff and state managers since 2004 have consistently said water was flowing into the tunnels from multiple entry points, and they have downplayed leaks as a major source. They said the project remained an active construction site even after the tunnels were opened to traffic in 2003, and that water flowing through open construction conduits would be cut off when construction ended.
But a report by the engineering firm Wiss, Janney, Elstner Associates Inc. for the Turnpike Authority last month for the first time quantified the amount of water by its source. The firm said the largest source, 40 percent, came from leaks. The second largest was rainwater flowing into the tunnel entrances.
Specifications in the contract with Bechtel/Parsons Brinckerhoff called for dry tunnels, and the turnpike in its application for an environmental permit issued in 2003 anticipated pumping only 36,000 gallons of water monthly used to clean the tunnels. In fact, about 2 millions gallons of water gets pumped out of the tunnels monthly, according to pumping records. That means about 800,000 gallons comes into the tunnels monthly from leaks.
That water, besides rusting steel, is washing away the fireproofing sealant applied to the steel, Rooney said.
George Tamaro, an engineer brought to Boston to assist Ginsburg, has long considered cold weather the culprit. When concrete contracts in cold weather, it cracks, he said. And when it expands in warmer weather, new water paths may open.
In the Big Dig tunnels, the cracks are especially worrisome because the mammoth structure sits under the water table, pressed on all sides by saturated soil.
In November 2004, state officials first acknowledged hundreds of leaks in the tunnels. And in dozens of subsequent reports posted on the turnpike's website, Bechtel/Parsons Brinckerhoff said it reduced the number of leaks over a 12-month period to a handful.
That accomplishment required as many as 13 construction crews fanning out almost nightly throughout the tunnel in 2005 to seal leaks, according to the turnpike records. Sealing leaks required lanes in the tunnels - a mile-and-a-half section of busy Interstate 93 - to be temporarily closed for access to the leaks, which are clustered high above the roadway at the seam between the roof and walls. They are sealed by drilling into concrete and injecting chemicals - called grout - that expand in the presence of water and harden to block paths for water intrusion.
Construction crews made more than 1,300 such injections in 2004 and 2005, the records show. Some sealed leaks reopened, requiring a second seal.
Turnpike personnel declined to provide any records detailing the extent of sealing efforts made since 2005, but Rooney acknowledged the number of crews assigned to leaks bottomed out at one. He said he did not believe leak-sealing ever ceased altogether for any period.
Mac Daniel, a spokesman for the turnpike, said $52 million has gone into leak repairs in recent years, a cost shared by contractors and the state. Rooney could not provide costs for implementing the recommended program involving stepped-up repairs, but acknowledged it would cost millions of dollars. Still, there will be no holding back because of expense, Rooney said.
"Yes, there is water in the tunnels, but it is being managed now, and an incredible amount of resources are being used to fix it," he said. "I don't care how much it costs. Come back in a year and see."
Sean Murphy can be reached at smurphy@globe.com.
(Correction: Because of a reporting error, a Page One story Sunday about water infiltration in the Central Artery tunnels incorrectly described the contractual responsibilities of project manager Bechtel/Parsons Brinckerhoff for ensuring the tunnels did not leak. Bechtel/Parsons Brinckerhoff's contract did not contain a specification for dry tunnels; its contract required it to write construction contract specifications, which called for watertight tunnels, and to monitor construction companies for adherence to those specifications.) 