Impact of Stormwater Pipe Lining Materials on Water Quality: Field Study and Resulting Specifications

摘要

As many stormwater pipes and culverts have reached the end of their service life, their repair orreplacement is a large maintenance concern. Many commonly used culvert rehabilitationtechnologies entail the use of a resin or coating that cures to form a rigid liner within thedamaged culvert. However, water quality implications of these trenchless alternatives are notcompletely understood. A previous evaluation conducted by the Virginia Center forTransportation Innovation and Research discovered that installations of conventional (styrene-based) cured-in-place pipe (CIPP) can impact water quality. These findings led to thedevelopment of rigorous specifications by the Virginia Department of Transporation and otheragencies to prevent such impacts. The study reported herein included a determination ofpotential water quality impacts from two unconventional CIPP technologies and two spray-onlining technologies: vinyl ester-based (styrene-free) CIPP, styrene-based ultraviolet CIPP, acementitious spray-on liner, and a polyurea spray-on liner.Several field installation sites were monitored and water quality tests were conducted oneach newly installed liner. Water samples were analyzed for water quality indicators andproduct constituents, and sampling results were compared against regulatory standards andpublished aquatic species toxicity criteria. Results indicate that contaminants were released fromeach tested liner, but for some liners, water flow, dilution, and volatilization appeared to play animportant role in reducing impacts on water quality. Recommendations for specificationsinclude protective controls to prevent exceeding water quality standards or aquatic speciestoxicity thresholds, particularly in receiving waters with low flow and little dilution potential.