Big Dig found riddled with leaks

Engineers hired to investigate the cause of September's massive Big Dig tunnel leak have discovered that the project is riddled with hundreds of leaks that are pouring millions of gallons of water into the $14.6 billion tunnel system.

While none of the leaks is as large as the fissure that snarled traffic for miles on Interstate 93 northbound in September, the breaches appear to permeate the subterranean road system, calling into question the quality of construction and managerial oversight provided by Bechtel/Parsons Brinckerhoff on the massive highway project.

Finding and fixing all the leaks will take years, perhaps more than a decade, said Jack K. Lemley, an internationally known consultant hired by the Massachusetts Turnpike Authority to investigate the problem. Just repairing the section of wall where the September leak occurred will take up to two months and require closing of traffic lanes.

The engineers also said they have discovered documents showing that Bechtel managers were aware that the wall breached this fall was deficient from the moment it was built in the late 1990s, yet did not order it replaced and did not inform state officials of the situation.

As a result, retired judge Edward M. Ginsburg, who leads the state's independent legal team seeking to recover compensation for shoddy construction and negligent management of the project, is now in discussions with Attorney General Thomas F. Reilly's office as they consider a lawsuit targeting Bechtel and the contractor that built the wall section that leaked in September, Modern Continental.

Lemley said that the tunnels remain structurally sound and that the project's extensive drainage system, while pumping far more water than anticipated, is keeping water away from the road surface.

But Ginsburg said he was astonished by the breadth of the problem.

''I can honestly say we were shocked; I was dismayed and shocked," he said. ''I can assure you, we're going to make sure there is a thorough investigation."

Ginsburg's team has concluded that 26 million gallons of water have coursed through the project's drainage system since December, far more than the 500,000 gallons engineers expected the system to handle annually. However, the team said they are unsure exactly how much of the water came from the leaks and how much is from other sources, such as rain dripping through unfinished areas of the project.

Turnpike Authority Chairman Matthew J. Amorello, whose agency oversees the project, was not informed of the extent of the problem until after the September leak, said Turnpike General Counsel Michael Powers. But for more than two years, three private contracting firms hired to complete cosmetic finishes on the tunnels have instead been devoting significant time to searching for leaks and patching them.

Ginsburg said such leaks are the type of flaws that Bechtel managers or Turnpike Authority officials are supposed to refer to him for investigation. He said his team will demand that Bechtel and the construction contractors permanently fix the problem at their own expense, which he said would entail replacing sections of the thick concrete tunnel walls. ''That's not patching the walls, but having them rebuilt," he said.

Ginsburg could not estimate how much the complete repairs would cost.

Modern Continental Construction Co., the largest contractor on the project and the company that built the section of wall that leaked in September, issued a brief statement yesterday expressing confidence that ''the results of the investigation will conclude that Modern's workmanship was in accordance with contract plans and specifications." Modern Continental, which has undergone years of financial troubles, recently merged with another Big Dig contractor, Jay Cashman Inc.

Bechtel/Parsons officials also declined to be interviewed, and they issued a statement that read: ''While the cause of the September water leak in the northbound tunnel remains under investigation, it would be inappropriate for us to comment on specific allegations. While water does enter the tunnels in other locations, this should not be confused with that one incident. In a tunnel of this construction type seepage is inevitable, but is mitigated by proper engineering and maintenance programs, which have been planned for and are in place. The tunnel is structurally sound."

Lemley and the other engineers hired by the Turnpike Authority to conduct the investigation said the leaks were primarily the result of pockets of extraneous material, such as sand, gravel or clay lodged in the tunnel's concrete walls. The contractors failed to completely excavate the debris before they poured the concrete for the walls, creating weaknesses through which water can seep.

George J. Tamaro, who is widely viewed as the world's foremost expert on tunnel wall construction and is also on the team of engineers, said he was amazed that Bechtel signed off on the wall section that leaked in September. He said that particular section fell woefully short of basic professional and contractual standards.

''I don't think anybody should have accepted the conditions that are there now," Tamaro said.

Poring over thousands of pages of project records, Lemley and his team have found at least a half dozen more tunnel wall panels, which are about 6 feet wide and 3 feet thick, that may develop leaks as large as the one that erupted in September, Lemley said. Those sections are located near the September leak, in the northbound tunnel. But the team cautioned that they have surveyed only a small portion of the 3 miles of tunnel walls in the system.

Lemley also said records show that Bechtel has compiled a list of hundreds of other leaks elsewhere in the system. Most of the leaks are in the I-93 tunnel, though some have been documented in the Ted Williams Tunnel.

''We think there are several other panels that need to be opened up," Lemley said. ''You have to look at this over a long period of time. You're not going to identify all this in months. . . . You're talking years here, even a decade."

Powers, the Turnpike Authority's general counsel, said yesterday that hints of the extent of the leaks emerged last January when drainage pipes near the southern entrance to the I-93 north tunnel filled with ice, which covered portions of the roadway and resulted in two days of lane closures. Traffic backed up as far south as Milton.

Project officials said at the time that the water was seeping in from open, unfinished sections of the project. But the engineers said yesterday that a substantial amount of water was also coming from groundwater leaking through weak spots in the walls.

Lemley said yesterday that Bechtel and the Turnpike have yet to fix the September leak section and have yet to approve a design for the repair.

''We're two months into it, and we still have a deficient panel down there," said Lemley. ''I would have expected a much more aggressive effort to get this leak fixed."

According to a Nov. 3 report by Tamaro, the Sept. 15 leak occurred at a juncture in the tunnel where Modern Continental was building a section of wall to meet with an already completed stretch of tunnel built by Perini-Kiewit-Cashman. The leak broke through the wall roughly 80 feet below the street surface, one of the deepest points in the artery system.

In his report, Tamaro concluded that when the wall was being built in 1999, Modern Continental failed to remove debris that had accumulated in the excavation area. Tamaro found that a Bechtel field engineer overseeing construction noted in his field report that the wall did not conform to standards, but did not take any action.

Two years later, Bechtel engineers again noted the flaw, recording in project records in December 2001 the presence of ''a concrete blow out" in the wall and the fact that ''water is leaking at this blow out." But, Tamaro said, again nothing was done.

In addition, according to documents gathered by Ginsburg's team, Bechtel engineers had been discussing problems with wall leaks as early as June 24, 1998, when a top design manager issued a memo that highlighted ''a concern for slurry wall leakage."

''Our project specification requires that slurry walls be watertight," wrote engineer Anthony R. Lancellotti of Bechtel/Parsons Brinckerhoff. The project design anticipated minor dampness in the walls, but Lancellotti wrote: ''Running water and dripping through the walls is unacceptable and must be repaired by the contractor. . . . Slurry wall repairs need to be performed and leaks closed prior to installation of waterproofing to avoid damaging the material."

While the team of engineers readies its report for a possible lawsuit, Bechtel is conducting its own inquiry, which it will present to the Turnpike Authority. Shortly after the Sept. 15 leak, Bechtel officials said they expected to complete their investigation within weeks.

Reilly said yesterday that his office is ''involved in the effort to determine the cause of the leaks," which he called unacceptable.

In addition, the Federal Highway Administration, which provided most of the funding for the Big Dig, is awaiting the results of the investigation to determine if the federal government should take action against any of the firms involved.

Sean Murphy can be reached at Smurph@globe.com. Raphael Lewis's address is Rlewis@globe.com.