Date of Award
Doctor of Philosophy (PhD)
Sherri M. Cook
R. Scott Summers
Small systems represent 95% of United States’ drinking water systems, but they often face technical, managerial, and financial challenges. These challenges hinder small systems’ abilities to make sustainable treatment decisions and these issues are being exacerbated as regulations become more stringent and source water quality degrades due to population growth and anthropogenic pollution. To provide effective decision-support that is relevant to the tens of thousands of small systems, this dissertation aimed to: characterize and then assess the relative environmental impacts of common small system filtration and disinfection treatment processes; construct a decision making tool that navigates trade-offs between the multiple sustainability dimensions to provide a small system stakeholder with custom treatment recommendations; and provide insights on treatment process selection based on source water quality, stakeholder preferences, and regulatory requirements while considering design uncertainty.
Life cycle assessment was used to quantify the environmental impacts resulting from filtration and disinfection treatment processes. For filtration processes, the results showed that conventional filtration was more environmentally preferred for more pristine source waters. Biological filtration was more preferred when the source water was more degraded and treatment requirements were more stringent. For disinfection processes, chlorine was environmentally preferred to ultraviolet disinfection in most cases. Ultraviolet disinfection was preferred when its Cryptosporidium reduction benefits could be realized. Life cycle assessment and multiple-criteria decision analysis methods were used in unison to construct a comprehensive and rigorous decision-making tool for small systems. The tool is universal in its ability to provide small systems with insights for making a treatment decision under distinct source water qualities, stakeholder preferences, and regulatory requirements while considering design uncertainty. The tool was used to evaluate 60,000 diverse, simulated small systems. Results provided specific insights for diverse small systems that have different source water quality and treatment constraints. Also, the selected filtration process has the largest impact on a treatment train recommendation. Ultimately, different stakeholder groups (e.g., consumers, engineers, operators, and regulators) can gain insights, using site specific characteristics, to make sustainable treatment decisions that will improve drinking water quality.
Jones, Christopher Holladay, "Improving Multi-Objective Sustainability at Small Drinking Water Systems: Modelling & Decision-Support" (2019). Civil Engineering Graduate Theses & Dissertations. 487.
Available for download on Wednesday, May 13, 2020