Underground infrastructure renewal is a daily challenge for most municipalities in the US. The traditional open-cut pipeline replacement (OCPR) method has a negative impact on the environment, as compared to the trenchless cured-in-place pipe (CIPP) renewal method. The CIPP renewal involves the insertion of a resin-impregnated tube inside the host pipe through air inversion or by mechanically pulling in and inflating. This fabric tube is cured using steam, hot water, or UV light, resulting in the CIPP product. Trenchless methods of pipeline rehabilitation are preferred because of fewer environmental consequences. However, the pipeline engineering industry demands stronger bases for a better and more comprehensive comparison of the CIPP and OCPR methods. The objective of this paper is to review past literature corresponding to CIPP renewal and OCPR methods for sanitary sewers and to quantify and compare the carbon footprint of processes involved in the use of these two methods based on a case study. Published papers were identified reporting the ecological impacts of both methods over the period from 1990 through 2024. These impacts are evaluated using USEPA's TRACI 2.1 methodology in SimaPro software. Results show that CIPP renewal caused around 70% less environmental impact, 75% less impact on human health, and 60% less resource depletion as compared to the OCPR. The pipe material and outside diameter should be considered during the installation phase by CIPP and OCPR methods to allow a detailed comparative evaluation of their sustainability impacts. This case study can be further developed for analysing the environmental impacts and associated costs of the CIPP and OCPR methods for wastewater applications with different project and site conditions.
Karkhanis et al. (Thu,) studied this question.