Evaluation of the carbon footprint of an innovative sewer rehabilitation method

A benefit of trenchless methods touted by many practitioners when compared to open cut construction is lower carbon dioxide emissions. In an attempt to verify these claims, tools have been developed that calculate the environmental impact of traditional open cut methods and commonly used trenchless methods. As part of a U.S. Environmental Protection Agency (EPA)'s Research Program, one key area of research is a field demonstration program of innovative rehabilitation technologies. The purpose of the program is to: (1) gather reliable performance and cost data during the application of these technologies; and (2) make the capabilities of these technologies better known to the industry. As part of the technology performance evaluation, the carbon footprint of an innovative sewer rehabilitation technology was calculated using the e-Calc tool that was developed by Arizona State University. The inputs for the calculations came from field demonstration logs that tracked the durations and equipment for each major activity. The paper describes the carbon footprint evaluation of an innovative, spray-applied, fiber-reinforced geopolymer mortar for rehabilitating a severely deteriorated 60-in. concrete pipe. The trenchless method was found to have significant reduction in carbon footprint.