Big Dig Leaks Are Routine And Not Surprising, Company SaysBy Raphael Lewis
The Boston Globe -- Bechtel/Parsons Brinckerhoff, the private company that manages the Big Dig, said Monday that plugging leaks in the Interstate 93 section of the tunnels will take “months, not years,” as a routine part of finishing the $14.6 billion project.
“The leak problem is well under control,” said a letter Bechtel sent to reporters.
The five-page letter represents Bechtel’s first detailed effort to address publicly the issues raised in recent news stories about the leaks.
While the letter does not discuss the number of leaks in the tunnels -- state officials estimate there are currently 500 -- it asserts that “no waterproofing system is perfect.”
“Chasing water that inevitably seeps through walls and joints is a normal part of construction,” the report says. “The spots where water enters are systematically located and sealed one at a time.”
The letter emphasized that some water enters the tunnel through portions of the project under construction and “open to the weather.”
Matthew J. Amorello, chairman of the Massachusetts Turnpike Authority, which oversees the project, has said engineers have been unable to determine how much water is coming from open sections of the project and how much is seeping through imperfections in the tunnel walls and joints. The latter kind of leak is more troublesome because it suggests a broader, and potentially more lasting, problem.
On Nov. 10, the Globe reported that the tunnels had hundreds of leaks, based on interviews with outside engineers brought in by the Turnpike Authority to investigate a large breach in a tunnel wall Sept. 15.
In an interview with the Globe, Jack K. Lemley, one of those engineers, told the Globe that repairing the leaks would take “years, even a decade.” Lemley said that when one leak is plugged, water migrates to another weak spot in the wall and bursts through.
Bechtel officials said the company’s program to “locate and seal normal wall and roof leaks” is making significant progress and should be “substantially complete” this summer.