Date of Award

Fall 2023

Project Type

Dissertation

Program or Major

Civil Engineering

Degree Name

Doctor of Philosophy

First Advisor

Weiwei Mo

Second Advisor

Robin Collins

Third Advisor

Paula Mouser

Abstract

This PhD dissertation is dedicated to the understanding and enhancement of the sustainability of public drinking water systems, addressing both emerging contaminants and emergency contamination events. A key focus is placed on comprehending the tradeoffs encompassing public health, economic, and environmental aspects associated with different actions aimed at improving system resiliency. By providing drinking water authorities with the tools and methodologies to evaluate available options, this research aims to empower decision-makers in their efforts to strengthen their drinking water systems against a myriad of threats.

This dissertation commences by investigating the tradeoffs related to the treatment of PFAS-contaminated water. The growing threat posed by per- and polyfluoroalkyl substance (PFAS) chemicals necessitates a comprehensive examination of the life cycle environmental, economic, and human health performances of the systems proposed to treat them. Thus, a comparative analysis was conducted between centralized granulated activated carbon systems and decentralized certified point-of-use systems, using Merrimack New Hampshire as a test bed. Surprisingly, the centralized scenario, despite protecting all drinking water taps in the house, did not exhibit the best performance in terms of health impact reduction due to its relatively low perfluorooctane sulfonate removal efficiency. Among the various system upgrades investigated, the combination of granular activated carbon and ion exchange filters in a point-of-use application demonstrated the lowest environmental and human health impacts. This study has highlighted the viability of decentralized approaches which emphasizes the tradeoffs associated with treating all household taps to the highest quality as compared to the small subset treated by the point of use systems.

Furthermore, this dissertation delves into the examination of various countermeasures applicable during drinking water emergencies. By employing system dynamics and life cycle assessment methods, these studies evaluated the public health, economic, and environmental impacts associated with the deployment of powdered activated carbon, enhanced coagulation, system shutdown, and source switching emergency countermeasures. Through this research, significant tradeoffs have been observed between direct and indirect public health, economic, and environmental effects with countermeasures that result in lower public health and environmental impacts often requiring higher economic inputs. Additionally, this research highlights the strategic advantage of deploying multiple countermeasures together rather than implementing them individually. This emphasizes the importance of understanding the impacts and benefits associated with the different countermeasure deployment strategies available under emergencies. Together these studies show the necessity for informed decision-making which takes into account the tradeoffs associated with different response strategies during organic chemical spill emergencies.

Overall, this dissertation provides a comprehensive study aimed at investigating and understanding the economic, environmental, and public health tradeoffs associated with drinking water systems. By conducting comparative life cycle assessments and employing robust methodologies, drinking water authorities can make well-informed decisions that enhance their systems overall performance and sustainability. The findings and methodologies presented in this research contribute valuable insights to the field and pave the way for further advancements in ensuring the provision of safe, sustainable, and reliable drinking water to the public.

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