UV Cured-in-Place Pipe (CIPP) Overview

The North Davis Sewer District (District) is repairing or “rehabilitating” their existing sewer pipelines. The sewers being repaired have deteriorated and been damaged over many years of continuous service and require repairs to continue serving the community reliably. A trench-less “No-Dig” method called cured-in-place pipe (CIPP) rehabilitation will be used. This method has been successfully performed for 40 years in the US and compared to traditional “dig and replace” pipe repair, results in less disruption to residents and traffic in the community while work is performed.

A “cured-in-place pipe” is a resin saturated fabric liner. The pliable fabric liner is pulled or inverted into a deteriorated sewer pipe through an existing manhole and requires no or minimal excavation. Once installed, the liner is inflated and then cured using hot water, steam or ultra-violet light (UV). The time required to properly cure the liner depends on the curing method, diameter of the sewer, and thickness of the liner. Once cured, resin held by the fabric liner hardens and creates a “pipe within a pipe” replacing the existing sewer pipe.

CIPP requires flow in the sewer and from house connections to be re-routed while the liner is installed and cured. Sewage and flows from house connections are bypassed around the work area via pumps and piping at the surface. Home service is restored using robotically controlled cutting devices within the sewer, again without excavation in the road. Once all the services are cut out, the new pipe is cleaned, inspected, and returned to service.

Information regarding the District’s CIPP Lining Projects can be found on this page. To see recent construction activity, click on the Project Reports link.