Virginia Via Research Day Book 2026

Graduate Student Research Public Health

01 Spatial Analysis of Safe Drinking Water Act Violations in the United States of America

Almudena Sanz Gutiérrez 1 , PhD; Jenny Rempel 2 , PhD; Alasdair Cohen, MSc, MPH, PhD 1 Corresponding author: almudenasg@vt.edu

1 Population Health Sciences Department, Virginia-Maryland College of Veterinary Medicine, Virginia Tech 2 Energy and Resources Group, Rausser College of Natural Resources, University of California, Berkeley

health research, this bias assumes that relationships between determinants and outcomes are homogeneous across space, delivering potentially misleading results that are not correct for the whole area under investigation. Objective: The goal of this study is to map SDWA health-based violations in the US and characterize the variables associated with them. Methods: We are building a dataset from open access data sources, including the SDWIS, the recently released EPA CWS service areas, and census data. The EPA service area maps show the specific area covered by each system, allowing for a more granular look into the sociodemographic characteristics of the population served by each CWS. However, these maps also have numerous errors and missing data issues that we are addressing on a case-by-case basis. After linking CWS service areas to the systems history of SDWA violations, we will attribute population-adjusted sociodemographic census variables to each CWS based on spatial match between its service area and the census block group. This dataset will be used to map SDWA violations in the US, identify hot spots,

and fit geographically weighted regression models that characterize non-stationary determinants of these violations. Results: This study is currently in progress, and results are not complete, but we expect to share preliminary results at the VCOM Research Recognition Day on February 13. Conclusions: To our knowledge, this is the first study on drinking water that uses the EPA service areas, as well as the first one to apply complex spatial analysis techniques to the question of SDWA violations distribution and determinants in the US.

Background: Access to safe drinking water is a public health priority and key for dignity. Although recognized as human right by the United Nations, communities in the US still lack access to safe drinking water. Here, about 90% of the population gets tap water from public water systems regulated by the Safe Drinking Water Act (SDWA). Under the SDWA, the Environmental Protection Agency (EPA) sets and enforces drinking water quality standards. When community water systems (CWS) do not comply with these standards, they are in violation of the SDWA. All the information about CWSs and their SDWA violations is openly accessible in the Safe Drinking Water Information System (SDWIS), which has been used to study patterns and determinants of violations. However, the data in SDWIS does not allow for the determination of the specific area covered by each system, which is needed to explore variables beyond CWS characteristics and quantify the impact of the violations on public health. Previous studies have resorted to county-level data aggregation, which is the main limitation of existing research on SDWA violations distribution in the US. In addition, none of the previous country-wide studies has addressed the spatial stationarity bias. Often found in environmental

Table of Contents

35

2026 Research Recognition Day