A former plant manager at a New Jersey pipe plant was sentenced Monday to nearly six years in prison in a federal investigation into worker safety violations and pollution of the Delaware River.

John Prisque of Bethlehem, Pa., was sentenced to a 70-month term for convictions of obstructing the investigation into Atlantic States Cast Iron Pipe Co. in Phillipsburg and violating clean water and air regulations. Four others also face sentencing.

In one of the most serious instances, an employee was killed after being crushed by a forklift that prosecutors say had faulty brakes.

Atlantic States is a division of McWane Inc., based in Birmingham, Ala.