Research Pays Off: Creating Environmentally Sound Specifications for Culvert Rehabilitation: Virginia Applies Findings for Cured-in-Place Pipe Repair

Styrene, a common component in cured-in-place pipe (CIPP), can be toxic to aquatic species and is classified as a potential carcinogen by the Environmental Protection Agency (EPA); however, the potential environmental impacts of CIPP repair have been little investigated. The Virginia Department of Transportation (DOT) tasked the Virginia Transportation Research Council (VTRC) to evaluate the impacts of styrene-based CIPP repair on water quality. The research confirmed that discharges of styrene into the environment were occurring during styrene-based CIPP installations. The findings highlighted the need for more stringent controls of the installation process to prevent impacts to aquatic species and associated violations of water quality. The research findings also served as a foundation for candid discussions with industry representatives in the search for achievable process modifications that would satisfy environmental requirements.

Follow-up research revealed that lack of control over cure variables increased the chances of inadequate liner cure, potentially jeopardizing the structural strength and durability of the finished product. The research and the actions taken by Virginia DOT have generated attention from other states with similar concerns about styrene-based CIPP and other pipe repair technologies and have prompted several transportation agencies to review their pipe repair specifications more closely.