Assessing Private Well Water Quality in Mobile and Baldwin Counties, Alabama

Abstract

Approximately 43 million people in the United States rely on private well water. Lack of regulation is important due sources of contamination from geogenic and anthropogenic sources. One source of anthropogenic contamination that may impact well water quality is land use, specifically agricultural land use. Contaminants associated with agricultural land use include pesticides, herbicides and nitrate. An objective of this study was to understand if agricultural land use impacts nitrate concentration in private well water. We found a statistically significant relationship between agricultural land use and nitrate. Nitrate was also found to have an inverse relationship with pH, which was supported by interpolations, principal components analysis and a multilinear regression. Areas with lower pH can have more corrosive water which can leach toxic elements that may impact human health. Low levels of saltwater intrusion were also found in this study. In general, water quality was deemed as excellent using a Water Quality Index (WQI), which can be used to qualitatively understand water quality. Considering the vast amount of parameters affecting water quality, we determined that a more holistic approach should be taken when researching water quality. Lack of federal regulation means that well owners are solely responsible for ensuring their water is safe. The most effective way for well owners to understand their water quality is to get it tested. Well owners can test their water by sending it to a laboratory or purchasing an at-home test kit. At-home test kits can serve as a quick and cost-effective way for well owners to understand their water quality. However, there are several different test kits and principles that citizens may use to test their water. We aimed to determine which kits and principles were the most accurate and applicable for well owners. Combination test kits were determined to be the most accurate test kits. We also found that some tests, like bacterial test have limits of detection above the Environmental Protection Agency’s Maximum Contaminant Level (EPA MCL), which may give well owners a false sense of security in their water quality. Concentration ranges and increments on comparator charts may also impact result interpretation. Though there are some limitations to using at-home test kits, at-home test kits can provide a cheap and quick way to measure water quality.