Exploring water quality in Montana groundwater and understanding associated drivers of human health risk
Approximately 17% of the population of the United States relies on private wells for drinking water and in Montana that percentage is approximately 30%. At the national level, 22% of wells tested by USGS exceed water quality thresholds for human health for at least one parameter. While it is common to assess water quality related human health risks by comparing concentrations of individual contaminants to health thresholds, the cumulative risk of multiple contaminants is understudied. This team is refining a preliminary cumulative risk analysis using well water data in the MT GWIC database for Montana watersheds. Based on the sum of the ratios of median inorganic contaminant concentrations and EPA established health benchmarks, approximately half of wells in nearly half of our watersheds test unsafe for lifetime consumption. Addressing risks to human health from consumption of groundwater requires both mitigation of anthropogenic contamination sources and implementation of treatment or alternative sources at the point of use. Determination of which combination of these approaches can be effective requires understanding the circumstances under which anthropogenic versus naturally occurring contaminants are the primary drivers of risk. This research will 1) combine concentration data for a suite of inorganic analytes in groundwater into a single framework for evaluation of cumulative human health risk, with attention to identifying locations where anthropogenically derived contaminants make a larger contribution to cumulative risk than naturally occurring contaminants, and 2) conduct an initial coarse level assessment of land use controls on anthropogenic contaminant sources. including assessment of relative contribution by individual analytes.
Dr. Adam Sigler is an assistant professor in the Department of Land Resources and Environmental Science at Montana State University (MSU), as well as the Water Quality Specialist for MSU Extension. Dr. Sigler’s work and research range from water and nitrogen dynamics in dryland agriculture to building water quality monitoring capacity and creating educational programming for private well and septic owners. Dr. Margaret (Mari) Eggers is an associate research professor in environmental health at MSU. She previously lived on the Crow Reservation, where she taught science at the Tribal College for a decade and co-founded the Crow Environmental Health Steering Committee (CEHSC). Through the CEHSC, Eggers has been working since 2006 with Crow colleagues and others on community-engaged research and mitigation to reduce Tribal exposure to waterborne contaminants, improve access to safe drinking water, understand the impacts of climate change on water resources and community health, and increase community capacity to address these issues. As the Associate Director for MSU’s accredited Environmental Heath degree program, Eggers teaches environmental health, and serves on the national Environmental Health Accreditation Council. Dr. Michelle Grocke is an Associate Professor in the Department of Health and Human Development at MSU focused on rural health, social determinants of health, and health equity.