Leaks harm fireproofing of Big Dig

Water leaks in the Big Dig have damaged fireproofing material in at least 40 areas along the tunnel's ceiling, according to Big Dig officials, who launched a survey of the roadway after a chunk of the material fell onto the Interstate 93 breakdown lane during Monday evening's commute.

Most of the damaged areas, which typically measure about 2 square feet, are located near where the tunnel walls meet the roof, the area of more than 400 leaks in the tunnel that have also damaged light fixtures and other utilities in the roadways.

Big Dig officials stressed that the tunnel is safe and that the damaged areas have been covered with a fireproofing board until more of the fireproofing material, which is sprayed on, can be applied when the weather improves.

Mariellen Burns, the Big Dig spokeswoman, also said that most of the damaged material is not located directly over the roadway, where it could fall onto cars if it fell.

The fireproofing material, a cement-like spray, weighs about 50 pounds per cubic foot, which is probably too light to crack a windshield but heavy enough to scare motorists.

''This is something we will continue to monitor," Burns said.

Project officials declined to cite the estimated cost of repairing the fireproofing damage, but said they are pursuing the tunnel's construction contractors to foot the bill.

Those contractors are also being pressed to pay for leak repairs.

''It's not a huge process; it's not an enormous ticket item," Burns said. ''But it does require some setup to do this work."

The fireproofing problem is the latest headache to surface after the revelation last fall that hundreds of leaks riddle the Big Dig tunnel.

The leaks include flaws in the tunnel's massive slurry walls, which have been found to have construction defects in 44 locations, and more numerous leaks in roof areas, where the waterproofing system has been ineffective.

A number of investigations were launched after the leaks became public in November, and project officials are attempting to determine how widespread the problem is and how expensive it will be to repair it.

Michael P. Lewis, the state's Big Dig project director, said he expects the fireproofing problems to end when all of the roof leaks have been plugged, which he expects to happen by the time the project is finished in September.

Nineteen of the spots where the 2-inch-thick fireproofing substance was damaged were discovered during the two nights of inspections carried out this week in the wake of Monday's incident, said Burns.

The rest had been previously discovered by workers because, over the past several months, small chunks had fallen onto tunnel walkways or appeared discolored by water stains, Burns said.

Officials were planning to reapply fireproofing material this summer, she said.

But they were forced to carry out a full-scale inspection of the tunnel's fireproofing protective layer to make sure it was not a danger to motorists.

During this week's inspections, workers surveyed roughly 90 percent of the 1.2 million square feet of fireproofing material in the tunnel roof.

Governor Mitt Romney, a leading critic of the project's management, said he had been given no specific information about the fireproofing problem and thus was not prepared to comment on the safety of the tunnel.

However, he sought to reassure the driving public by saying that the Big Dig's $14.6-billion price tag seems to be a greater concern at this point than the spotty problem with fireproofing.

''I must be honest with you: I don't feel nervous as I go into the tunnel," Romney said. ''I don't worry that it's going to collapse. I don't worry that it's going to melt.

''But I am concerned that it's cost a heck of a lot of money," he said. ''We don't know why it's had the problems it's had."

Federal overseers are refusing to deliver their final $81 million Big Dig payment until the scope and cost of the leak problem and repairs become clear.

The Massachusetts Turnpike Authority, which oversees the project, has hired the audit firm Deloitte & Touche to account for all leak-related costs.

Keith Sibley, program manager for Bechtel/Parsons Brinckerhoff, said he expects engineers to complete their survey of the tunnels' 2,000 wall sections by the end of the month.

So far, a little more than 4 percent of the slurry wall sections inspected have contained construction flaws.

The oversight of the construction by Bechtel/Parsons Brinckerhoff and the company's role in the leak problem have become a focus of the state's cost-recovery efforts being headed by state Attorney General Thomas F. Reilly.

At a press briefing yesterday, First Assistant Attorney General Stephanie S. Lovell said her office was hoping that the tunnel's contractors would soon propose a reasonable solution to fixing and paying for the leak damage and negotiate an out-of-court settlement with the state over allegations of mismanagement and shoddy construction.

Anticipating such talks, Reilly's office yesterday put a $150 million breach-of-contract lawsuit against Bechtel/Parsons Brinckerhoff on hold for six months, but insisted that the suit remains alive in the event that talks break down.

Raphael Lewis can be reached at rlewis@globe.com.