The majority of the city’s sanitary sewer mains were constructed in the late 1950’s and early 1960’s, utilizing clay tile pipe. Over time, the joint materials have failed, allowing root intrusion. Clay pipe is also susceptible to cracking and construction damage. The conventional method of digging and replacing the pipe (“open-cut replacement”) is very expensive, and disruptive to property owners.
Cured-in-Place Pipe Lining
The city’s Capital Improvement Plan includes annual funding for a sanitary sewer main lining program to extend the life of our sanitary sewers by 50 years or more. This technology, called cured-in-place pipe (CIPP) renewal, installs a new resin pipe inside the old clay tile sewer main without digging up city streets, which results in minimal disruption to residents during construction.
The liner pipe is inserted into the main through existing manholes and cured in place with a heat or steam process. Any given segment is usually completed in one working day. Service line connections are reopened using a robotic cutter and remote cameras. During the process, existing flows are bypassed using pumps.
This technology has been proven over the past 20 years, and has become more cost-effective than open cut replacement. We expect that this type of renovation will become an annual project for the foreseeable future as our sewer infrastructure continues to age. This technology also prevents infiltration of groundwater into the system and can be credited toward a required inflow / infiltration program.