The intent of chemical grouting in sewer systems is to seal leaks and stop infiltration and exfiltration.  Most leaks in structurally sound sewer systems are through pipe joints, manholes, service connections, and the first few feet of service laterals.  The most economical way to stop those leaks is with chemical grout.

AvantiGrout:
In addition to stopping infiltration and exfiltration within the sewer system, Avanti grouts also stabilize the soil outside and around the sewer pipes and manholes, which strengthens the soil and provides longer-lasting support. Avanti chemical grouts have been used to prevent erosion and to stop hazardous waste migration.