An Index to Quantify Disparities in Public Potable Water and Wastewater Treatment Systems: The Tennessee Case Study

Safe drinking water and wastewater treatment are some of the most important, yet least noticed, technological advances in the modern world. Without it, much of society and industry would not be able to function. Yet, many people, both in wealthier and disadvantaged countries, still lack access to these essential services. Research on reliable potable water access and safe sanitation in wealthier countries, especially the United States, is sparse. Moreover, current research typically focuses on a single factor contributing to a lack of access; studies looking at multiple factors affecting the reliability and quality of treatment services are almost nonexistent. To alleviate this knowledge gap, our study seeks to determine if disparities in drinking water and wastewater treatment exist in rural and low-income communities in Tennessee, and if the disparities exist, how the rural and low-income communities are affected. Counties were categorized by economic classification and three were randomly selected from each group. Drinking water and wastewater disparity indices were developed to determine the quality of access to drinking water and wastewater treatment in the selected counties. The indices consider numerous variables related to access, treatment infrastructure, and affordability of treatment services. Results from both indices suggest that the correlation between rurality and disparities in drinking water and wastewater is not significant. A county’s economic classification was found to be significantly correlated with disparities in drinking water treatment, but not with disparities in wastewater treatment. Further research, including application to additional counties, reliable data sets, and determining optimal weights for each variable, is necessary to strengthen the indices.

Safe and affordable public drinking water and wastewater treatment are not equally distributed, even in wealthy countries such as the United States. Many issues plague existing public drinking water and wastewater systems, including aging infrastructure, accessibility, and increasing costs of upgrades and treatment. These complex issues make it challenging to identify regions within the United States or within a state that needs investment to improve treatment infrastructure and its operations. To address this challenge, this study developed disparity indices. Variables considered in the disparity index included access to a public drinking water or wastewater system, state of the treatment infrastructure, and the ability of residents to pay for the service, therefore enabling the evaluation of disparities in drinking water and wastewater at the county level in Tennessee. Our research revealed that disadvantaged and rural counties may experience more disparities compared to wealthy and urban counties. The disparity indices offer a comprehensive tool that can be used by regulators and decision makers to prioritize technical and financial assistance for communities lacking reliable public water and wastewater infrastructure.