Evaluation Of Environmental Effects of Cured-In-Place Pipe (Culvert) Rehabilitation

Focus Area

Construction and Maintenance Practices


Environmental Process, Natural Resources




Under $99,000


Under 1 year

Research Idea Scope

Research problem statement – Cured in place (CIP) pipe replacement can have severe environmental effects on workers as well as aquatic resources because of the use of the toxic styrene. Little to no environmental analysis has been conducted on the effects of this technology, nor the degree it is in widespread use. Best Management Practices need to be identified and disseminated for use in other locations. This is a trenchless technology, and at least in Virginia, it has replaced the conventional expensive method of unearthing the entire pipe for replacement. The process involves inserting a flexible liner, which is coated with resin, into the damaged pipe. The resin is then cured with steam or hot water until the liner expands and hardens – resulting in a pipe within a pipe. Surprisingly, there have been little to no studies on the environmental impacts of this process. The resin that coats the liner contains styrene – a very toxic chemical that kills aquatic life (let alone the fact that it is potentially harmful when inhaled).   It is very difficult for the workers to avoid getting extra resin into the drainage channel or stream beds while pulling the liner through the host pipe. Often, the companies contracted to do this work have been releasing the hot curing water (or the condensed water if steam is used) into the stream itself. This is a direct violation (since the water is hot and contains styrene), but it’s much easier and cheaper than trucking the water off to a disposal site. Even if the water were disposed of properly, there is speculation that even weeks/months after the project is complete, styrene from the hardened resin can permeate through the liner and become flushed down the drainage channel or stream. Other relatively new pipe repair methods (not just cured-in-place) may also need investigation, such as the process where polyfoam is sprayed in the damaged pipe. Objectives – To evaluate and control environmental impacts associated with CIP pipe rehabilitation. Research proposed – Investigate the impacts

Urgency and Payoff

If CIP technology is becoming widespread but the environmental impacts are unknown, both worker safety and aquatic resources are potentially at great risk.

Suggested By

ADC30, Ecology and Transportation Committee, as specified in the TRB Research Needs Database, 2009. (Submitted to TRB Database 6/2007)