Impact of Stormwater Pipe Lining Materials on Water Quality

Abstract

Many stormwater pipes and culverts have reached the end of their service lives, and their repair or replacement is a large maintenance concern. Many commonly used culvert rehabilitation technologies entail the use of a resin or coating that cures to form a rigid liner within the damaged culvert. However, water quality implications of these trench-less alternatives are not completely understood. A previous evaluation conducted by the Virginia Center for Transportation Innovation and Research, a division of the Virginia Department of Transportation (DOT), discovered that installations of conventional (styrene-based) cured-in-place pipe (CIPP) can affect water quality. These findings led the Virginia DOT and other agencies to develop rigorous specifications to limit water quality impacts. The purpose of the present study was to determine the water quality impacts caused by vinyl ester–based CIPP and ultraviolet CIPP technologies as well as cementitious and polyurea spray-on liners. Water quality monitoring was conducted at several field installation sites, and specimens of certain newly installed liners underwent laboratory testing. Water samples were analyzed for specific contaminants (i.e., styrene, vinylic monomer) as well as general water quality indicators (i.e., pH, organic carbon). Results indicated that contaminants were released from each material, but results were not similar across the three test methods applied. Water flow, dilution, and contaminant volatilization seemed to affect water quality results. Recommended specifications include protective controls to prevent water quality standards and aquatic toxicity threshold exceedances, particularly for those receiving waters with low flow and little dilution potential.