BOSTON -- Two former managers of a Big Dig contractor pleaded guilty Wednesday to being part of a conspiracy to deliver substandard concrete to the massive highway project.
Six former managers of Aggregate Industries NE Inc. were indicted in 2006 on charges they falsified records to hide the inferior quality of more than 5,000 truckloads of concrete.
They were accused of recycling concrete that was too old or already rejected by inspectors and in some cases double-billing for the loads.
Gerard McNally, a former quality control manager, and Keith Thomas, a former dispatch manager, pleaded guilty to 12 charges, including 2 conspiracy counts, five mail fraud counts and five counts of filing false reports in connection with a federal highway project.
A prosecutor said in court Wednesday that as part of their plea agreements, both McNally and Thomas have agreed to cooperate against the other four men and will testify against them during their trial, which is scheduled to begin Monday in U.S. District Court.
The men who are going on trial are: John Farrar, of Canterbury, Conn., a former dispatch manager; Robert Prosperi, of Lynnfield, a former general manager; Marc Blais, of Lynn, a former dispatch manager; and Gregory Stevenson, of Furlong, Pa., former district operations manager.
Laywers for McNally and Thomas would not comment on their plea agreements. Sentencing was scheduled for Oct. 1.
In 2007, Aggregate pleaded guilty to fraud and agreed to pay a $50 million settlement to end civil and criminal investigations into substandard concrete it delivered to the project. Under the settlement, Aggregate was allowed to avoid debarment, a sanction that would have barred the company from bidding on state and federal contracts.
Formally called the Central Artery and Third Harbor Tunnel project, the Big Dig buried Interstate 93 in tunnels beneath downtown and connected the Massachusetts Turnpike to Logan Airport with a third tunnel beneath Boston Harbor.
The $15 billion Big Dig - considered the costliest highway project in U.S. history - was plagued by construction problems, leaks, falling debris and huge cost overruns.
On July 2006, Milena Del Valle and her husband were driving through an Interstate 90 connector tunnel when 26 tons of concrete ceiling panels crashed onto their 1991 Buick, crushing to death the 39-year-old mother of three.
But the case against Aggregate was never connected to this crash.
The NTSB's July 2007 accident report said the wrong type of adhesive was used to secure the concrete slabs in the tunnel ceiling, and the Massachusetts Turnpike Authority contributed to the accident by failing to implement a timely tunnel inspection program.