Graduation Semester and Year
Fall 2025
Language
English
Document Type
Thesis
Degree Name
Master of Science in Civil Engineering
Department
Civil Engineering
First Advisor
Vinayak Kaushal, Ph.D., P.E.
Abstract
The advancement of underground infrastructure is vital to the development of modern society and continues to inspire technological progress. As environmental concerns grow, innovative approaches to pipeline rehabilitation are increasingly emphasizing sustainability. Assessing and contrasting the environmental effects of renewing existing pipelines versus complete replacement is key to fostering eco-conscious improvements in subsurface utility systems. Cured-in-Place Pipe (CIPP) is a commonly used trenchless method for rehabilitating pipelines. It involves inserting a flexible liner, saturated with resin, into the existing pipe. This insertion can be achieved through inversion using air or water pressure, or by mechanically pulling and inflating the liner. Once in place, the resin is cured using heat sources such as hot water, steam, or ultraviolet (UV) light, forming a hardened, structural lining within the host pipe. Life Cycle Assessment (LCA) is a systematic approach used to evaluate the environmental effects associated with a product, process, or service throughout its entire life span. It serves as a valuable tool for forecasting environmental impacts and developing appropriate environmental management strategies. The assessment draws on data related to raw materials, production processes, and manufacturing activities to identify emissions and other environmental consequences linked to the product. The objectives of this thesis are to: (1) conduct a comprehensive literature search and review of environmental emissions and LCA from CIPP sewer rehabilitation method, (2) quantify carbon-dioxide equivalents (CO2e) and non-methane volatile organic compounds (NMVOCe) emissions generated during CIPP installations for 8-inch, 10-inch, and 12-inch pipe diameters using life cycle assessment techniques, (3) compare environmental impacts under the tool for reduction and assessment of chemicals and other environmental impacts (TRACI) and ReCiPe frameworks, identifying dominant categories such as global warming, smog formation, ecotoxicity, and human toxicity, and to apply weighted factors for CO2e and NMVOCe to determine their relative contribution to overall environmental burden, (4) evaluate the environmental significance of NMVOC-related impacts, particularly smog formation and toxicity effects, in comparison to CO2e -driven global warming, and (5) provide recommendations for minimizing emissions during CIPP processes, supporting more sustainable decision-making in pipeline rehabilitation. Real case studies from CIPP projects in the United States were examined, focusing on small-diameter sewer pipes (8–12 inches), to quantify CO2e and NMVOCs environmental impacts using two LCA approaches: TRACI 2.2 and ReCiPe 2016 Midpoint (H). Weighted factor of 79.7% for CO2e and 20.3% for NMVOCe as per EPA GHGI 2017 was applied as the overall environmental burden is primarily driven by CO2e, confirming that greenhouse gas emissions dominate the life cycle impacts. The TRACI results demonstrate that for evaluation of environmental impacts from CIPP renewal, CO2e contributes approximately 97.89% of the total environmental impact, while NMVOCe contributes about 2.11%, confirming that greenhouse gas emissions overwhelmingly dominate compared to NMVOC-related impacts. Similarly, ReCiPe results indicate that global warming remains the highest contributor while NMVOCe significantly influences human toxicity categories, with non-carcinogenic toxicity for 8-inch pipes. This demonstrates that while climate change impacts dominate, NMVOC emissions cannot be ignored due to their localized health and ecosystem effects. The comparison between TRACI and ReCiPe methods represents alignment in identifying global warming as the most significant impact category, but they differ in secondary impact emphasis. TRACI highlights smog formation and ecotoxicity as major NMVOC-driven impacts, whereas ReCiPe emphasizes human toxicity (both carcinogenic and non-carcinogenic) with extremely high values for NMVOCe. This indicates that TRACI is more focused on atmospheric and ecosystem-level effects, while ReCiPe provides a deeper insight into human health implications, for CIPP renewal. Findings from the literature and analysis of results underscore the environmental advantages of CIPP over other pipe renewal methods, while also identifying areas for improvement, particularly in reducing CO2e and NMVOCe emissions. The proposed LCA approach will also help in the municipalities, utility managers, and contractors, enabling more sustainable infrastructure planning. This approach can be extended to assess varying pipe diameters, resin types, curing techniques, and site conditions, contributing to a broader understanding of sustainable practices in sewer rehabilitation.
Keywords
Life cycle assessment, Trenchless technology, Cured-in-place pipe (CIPP), Pipeline renewal, Wastewater applications, SimaPro, Midpoint approach, Environmental sustainability, Emissions
Disciplines
Construction Engineering and Management
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Mandari, Shiva, "LIFE CYCLE ASSESSMENT APPROACH FOR TRENCHLESS CURED-IN-PLACE PIPE SEWER RENEWAL METHOD" (2025). Civil Engineering Theses. 464.
https://mavmatrix.uta.edu/civilengineering_theses/464