Four former employees of a company convicted of supplying substandard concrete to Boston's troubled Big Dig highway project have avoided prison time for their roles in the scheme. A federal judge sentenced Mark Blais and John Farrar to probation, home confinement and community service. The judge sentenced two others to probation and home confinement.

Federal prosecutors had requested prison time. U.S. Attorney Carmen Ortiz says the government is "disappointed" by the sentences. The Big Dig replaced an elevated highway with a series of tunnels, ramps and bridges. It was plagued by cost overruns, falling debris, leaks and other problems. Aggregate Industries Northeast Region says only a tiny percentage of the concrete it provided was ruled noncompliant with specifications.