While controlling main-line inflow and infiltration, the Rockland (Mass.) Sewer Depart-ment faced another challenge: groundwater migrating into the sewers through 6-inch vitrified clay laterals.Heavy infiltration during spring and fall pushed the treatment plant’s limited capacity, affecting the town’s ability to grow. Repairing the laterals became the next major objective. An inspection by Metcalf & Eddy Inc., an environmental engineering company in Wakefield, Mass., identified leaking joints 20 feet up the service connections. The engineers decided that grouting was the most economical solution.National Water Main Cleaning Co. (NWMCC) in Canton, Mass., a division of Carylon Co., won the repair contract. “We
