Investigating Private Drinking Water Quality and Biomarkers of Associated Health Outcomes in Southwest Virginia

Abstract

Approximately 1.8 million Americans living in rural communities do not have access to safely managed household drinking water. Recent research has demonstrated high rates of the US Environmental Protection Agency's (EPA) Safe Drinking Water Act (SDWA) violations in rural areas and heavy dependence on private systems that are not subject to SDWA monitoring and treatment requirements. Few studies concurrently examine both the quality of private drinking water and associated biomarkers of disease. This relative lack of data is particularly acute in Central Appalachia, a region defined by high poverty, aging public infrastructure, and high rates of private water supply. This study aims to measure the prevalence of health outcomes associated with drinking water from a private or environmental source in a rural, Central Appalachian region in Virginia. To accomplish this goal, participating households with drinking water supplied by a private well, spring, or environmental source (e.g. roadside springs) participated in a three-step process: surveys administered by trained teams, drinking water samples collected at the point of use, and health outcome measurements. Water samples were collected from the point of use without flushing, after sanitization and a 5-minute flush, and from any non-bottled, alternative drinking water sources. These samples were analyzed for fecal indicator bacteria, specific enteric pathogens, metals, nutrients, and other inorganic ions. Though private sources are not subject to EPA regulations, water quality results were compared to US EPA maximum contaminant levels (MCLs), secondary maximum contaminant levels (SMCLs), and health reference levels as benchmarks. Measurements of health outcomes included immunoassays of saliva samples and blood pressure measurements. At least one sample from ~73% (n = 11) of eligible households contained detectable total coliforms and ~27% (n = 4) contained detectable E. coli. One quarter of eligible households (n = 3) had water containing specific enteric pathogens, all of which were supplied by a private spring. No samples exceeded health-based standards (MCLs) for inorganic constituents. Only one individual reported experiencing symptoms of enteric waterborne disease, which coincided with detection of Aeromonas in their primary drinking water source. However, the participant also noted a change in medication as a confounding factor for their symptoms. Blood pressure measurements revealed high prevalence (~69%, n = 11) of hypertension despite fewer participants (25%, n = 4) reporting the condition, reinforcing the need for measured health outcomes. Due to recent changes in federal funding and hiring practices, saliva samples were unable to be analyzed and strong epidemiological associations between private drinking water use and enteric disease remain out of reach. Despite this, biological contamination of private and environmental drinking water sources remains prevalent in Central Appalachia.