Suburban Lancaster Sewer Authority – Transite Pipe Lining Program

Suburban Lancaster Sewer Authority (SLSA or Authority) is a municipal sewer authority located in Lancaster County, Pennsylvania. In an 18-month period from 2007 to 2009, SLSA experienced three pipe collapses that brought about much concern on the state of their collection system. After further investigation, it was discovered that deteriorated asbestos cement pipe (ACP) was the common thread among the three instances. Further investigation confirmed that certain locations with increased hydrogen sulfide (H2S), such as downstream of pumping station forcemains, were extremely corroded and needed immediate action. From that point forward, SLSA sought a cost-effective means of repair that would prevent costly emergency action and ensure the structural integrity of the pipes.SLSA turned to cured-in-place pipe (CIPP) lining as their repair method of choice, and began a seven-year, phased program to rehabilitate all ACP in the collection system (eight distinct projects). While not all ACP was as deteriorated as others, SLSA wanted to be as proactive as possible to eliminate the threat of collapse in all the ACP within the collection system. Utilizing SLSA’s geographic information system (GIS) CDM Smith Inc. (CDM Smith) located all the ACP in the system and separated the pipes into three categories by potential H2S exposure: Downstream of a pumping station forcemain, downstream of drop manholes, and all other ACP. Further break down was done by geographic area to delineate projects for public bidding.While the pipe collapses were unexpected and necessitated immediate action, the Authority was able to regain control by implementing their proactive Transite Pipe Lining Program. There were bumps along the way, but the result was more than 31 miles (1/3rd) of the collection system being lined. SLSA now has the peace of mind that they now have a structurally sound and more resilient collection system for the future.