Evaluation of karst spring water quality in northeast Tennessee using water quality indices

Abstract

Ensuring access to safe drinking water to protect public health in communities underserved or unserved by centralized water systems requires regular water quality testing and reporting. However, households depending on unregulated water systems like wells and springs, which are less routinely tested, may be unaware of their water quality. Access to easy‐to‐comprehend water quality information may be challenging. Therefore, this study utilized multiple water quality parameters to determine karst spring water quality using two water quality index (WQI) methods. This approach aggregates and summarizes water quality data into a single value or index characterizing the general health status of water at a given location in an easy‐to‐understand way. In situ measurements of physicochemical parameters (pH, dissolved oxygen, temperature, turbidity, conductivity, specific conductance, total dissolved solids, and oxidation–reduction potential) were taken at 50 karst springs in east Tennessee during summer 2021. Water samples were analyzed for microbial (fecal coliform and Escherichia coli), nutrients (nitrate and nitrite), and radiological (radon) constituents using standard analytical methods. WQI method 1 (Brown et al. Water Quality Index) rated 12% of springs as “very poor” water quality and 88% as “unfit for drinking.” WQI method 2 (National Sanitation Foundation Water Quality Index) rated 4% of the sampled springs as “good,” 92% as “moderate,” and 4% as “bad.” Given the prevalence of fecal contamination in the sampled springs, even springs rated good should be properly treated before consumption. Overall, these findings demonstrate the importance of selecting appropriate WQI for the end water use, and for water quality information that is easily understandable by water users.