A federal grand jury sitting in Boston has handed up a 135-count indictment against six employees of Aggregate Industries NE Inc., Saugus, Mass., for allegedly supplying at least 50,000 cu yd of inferior concrete to the $14.6-billion Central Artery/Tunnel job

The 40-page document charges that the six conspired to defraud the government by providing non-specification concrete and falsifying batch slips. The concrete was used in the Interstate 90 and 93 tunnels. The I-93 tunnel has been under repair for leaks.

Named in the May 4 indictment are Aggregate General Manager Robert Prosperi, 64, Lynnfield; District Operations Manager Gregory A. Stevenson, 53, Furlong, Pa; Quality Control Manager Gerard M. McNally, 54, Rockland; Dispatch Managers John J. Farrar, 43, Canterbury, Conn., and Marc Blais, 36, Lynn; and Assistant Dispatch Manager Keith H. Thomas, 51, Billerica. All are charged with conspiracy to commit highway project fraud and mail fraud, conspiracy to defraud the government with respect to claims and making false statements in connection with highway projects. ;

The ongoing investigation may produce more indictments. �Today�s indictment and subsequent arrests reflect the commitment of the [U.S.] Dept. of Transportation and Dept. of Justice to ferret out and vigorously prosecute those who seek to cheat the taxpayers,� says Ted Doherty, DOT special agent.

The indictment purportedly follows a whistleblower complaint that led to search warrants being executed last July. The alleged offenses took place between 1996 and August 2005, when the defendants delivered 5,000 truckloads of non-specification concrete. Each load was approximately 10 cu yd. The indictment charges that the six used concrete that was more than 90 minutes old, adulterated with excess water or not batched to project specifications. The defendants also allegedly used concrete left over from other customers� jobs that did not meet CA/T specs.

�In the wake of arrests made this morning of six mid-level current and former employees, the company will continue its ongoing, full and comprehensive cooperation with federal and state authorities in the government�s project-wide investigation of contractor practices and project oversight of the Big Dig,� says Aggregate Industries spokeswoman Nancy Sterling. �The four current employees have been suspended.�

According to the U.S. Attorney's Office, Aggregate received over $105 million in CA/T contracts between 1999 and 2004. During the same period, it delivered 133,721 loads of concrete. Five defendants have been released on $100,000 bail each, another for $250,000. All are to appear in federal court May 11.

According to DOT, CA/T consumed about 3.8 million cu yd of concrete. About 120,000 sample cylinders were taken, 75,000 in the three peak construction years of 1999, 2000 and 2001. Cylinders were tested at intervals of 7, 28 and 56 days. The overall failure rate was less than .5%. �Project management is set up to control quality but cannot always uncover willful fraud,� says Andrew M. Paven, spokesman for project consultant Bechtel Parsons/Brinckerhoff.

Aggregate Industries is the largest asphalt and concrete supplier in the region and is a subsidiary of Aggregate Industries Inc., Bethesda, Md., which was owned by Leicestershire, England-based Aggregate Industries PLC. Jona, Switzerland-based Holcim LTD purchased that firm in 2005.