BOSTON — The Big Dig, the country's most ambitious and most costly public works project, is leaking.
A flood in one of the tunnels was followed by the disclosure that Big Dig engineers had documented as many as 500 leaks in the $14.5-billion highway and parks project. Documents obtained by the city's two daily newspapers showed that state and federal officials knew of waterproofing problems as early as 1997 -- when the project was not yet half-completed -- and quietly established a leak task force the same year.
The revelations so unnerved drivers that 65% of commuters interviewed in an informal survey last week by a television station said they felt unsafe using the Big Dig tunnels. Their anxiety was not eased by an article in the Boston Herald describing what to do in the event of a tunnel flood.
"Keep a working flashlight in your car and a whistle with you at all times so you can call for help," the article advised.
The Big Dig is a system of tunnels and underground roads that replace an elevated expressway that marred Boston's waterfront and separated the historic North End from the rest of the city. The expressway was the region's most heavily traveled artery, carrying urban commuters as well as travelers to New Hampshire and Maine.
With revelations unfolding each day about allegedly shoddy construction and lack of oversight, irate federal and state officials spent last week pointing fingers at one another, and at the Big Dig's major contractor, Bechtel/Parsons Brinckerhoff.
Gov. Mitt Romney demanded the resignation of Massachusetts Turnpike Authority Chairman Matthew J. Amorello, whose agency oversees the project.
"Somebody obviously messed up big-time," Romney said last week. "And that's just one more example of a long list of blunders related to the Big Dig."
Amorello -- who has likened the Big Dig to the construction of the Panama Canal -- refused to step down from the job he assumed in 2002, more than a decade into the project's construction.
The Turnpike Authority chairman spent much of last week fending off criticism as engineers discovered a new tunnel section with a defect similar to one that caused flooding in September.
Amorello insisted that the breach in a tunnel wall that was supposed to be watertight was not related to hundreds of leaks throughout the underground system. He blamed Bechtel/Parsons Brinckerhoff for improperly installing and sealing the wall. He said the defect would be corrected at no cost to taxpayers.
The chairman said the vast array of smaller leaks -- some as tiny as pinpricks -- was a separate issue. Amorello said Big Dig engineers had been "identifying and repairing leaks in the tunnel system since the roadways opened last year."
Amorello noted that although most of the Big Dig tunnels were open, the project was still almost a year from completion. More than a dozen areas in the tunnels remain under construction and have not been waterproofed.
Most of the tunnels in the seven-mile-long project run under the city but sit below the water table of the nearby harbor. No one was injured in the September flood, though it produced major traffic delays.
Turnpike Authority spokesman Doug Hanchett said Friday that contractors would be held accountable for construction flaws.
Moreover, Hanchett said, "the tunnels are completely safe." He said neither the breach in September nor the ongoing leaks had jeopardized the safety of the tunnel.
Bechtel spokesman Andy Paven dismissed the notion that the Big Dig was riddled with potentially perilous fissures.
"Almost all of these 'leaks' are either trickles of water or wet spots on a wall," he said. "Waterproofing -- chasing down leaks -- is an art, not a science, and that process has been going on. There is a public perception that because people could drive through it, we had reached Nirvana and this project was complete. In fact there is a lot of messy work to do to clean the whole thing up."
For some drivers, such reassurance was of scant comfort. A local comedian dubbed the Big Dig the world's biggest underground car wash. And one commuter told the Boston Globe that he felt like he was driving to work in "a pre-dug grave."
Even before the tunnels began springing leaks, the Big Dig was notorious for massive cost overruns and for running more than five years behind schedule. The project has been saddled with ongoing charges of fraud and mismanagement.
The Big Dig was championed by Sen. Edward M. Kennedy and the late House Speaker Thomas P. "Tip" O'Neill. The powerful pair of Massachusetts Democrats overran opposition from then-President Reagan as they secured a record level of federal funding for the project.
The Big Dig provides the first direct connection between the Massachusetts Turnpike and Logan International Airport.
When the project is finished, a park will fill much of the area where the expressway once stood.