Environmental Impact Assessment of Trenchless Cured-in-Place Pipe Renewal Method for Sanitary Sewer Applications

Environmental impact assessment is a scientific method for analyzing the environmental impacts associated with the life cycle of a product. The information about the raw materials, processes, and product manufacturing are evaluated to obtain the associated emissions and other ecological impacts. Trenchless cured-in-place pipe (CIPP) renewal method involves a liquid thermoset resin saturated material that is inserted into the existing pipeline by hydrostatic or air inversion, or by mechanically pulling-in, and inflating. The liner material is CIP using hot water, steam, or light cured using ultraviolet light resulting in the CIPP product. The objective of this paper is to evaluate the environmental impacts of CIPP renewal method for sanitary sewers and to identify influencing factors impacting environment. The environmental impact assessment was carried out with the help of SimaPro software using Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts (TRACI) method. TRACI has factors for normalization to allow for comparison between impact categories, which divides the calculated outputs for the individual impact categories by the averaged impact values for each impact category. Results show that the CIPP liner, felt, and resin contribute significantly to the environmental impacts of CIPP renewal. It can be concluded that environmental impact assessment of CIPP renewal method is a vital element when considering sustainable infrastructural development. This study can be useful for analyzing the environmental impacts and associated costs of CIPP renewal for sanitary sewers with different project and site conditions.