Boston A concrete supplier for the Big Dig has agreed to pay $50 million to end civil and criminal investigations into whether it supplied inferior concrete used in the massive highway project, authorities announced Friday.
Aggregate Industries NE Inc. also agreed to plead guilty to a criminal charge of conspiracy to defraud the federal government.
Six employees of Aggregate, which supplied concrete used in tunnels and roadways in the Big Dig project, were indicted last year on federal charges that they falsified records to hide the substandard quality of 5,000 truckloads of concrete.
The indictment charged the men with recycling concrete that was too old or did not meet contract conditions and, in some cases, double-billing for the loads. The company was paid $105 million for 135,000 truckloads of concrete, and more than 5,700 of those truckloads did not meet specifications, according to the indictment.