ASSESEMENT OF GROUNDWATER QUALITY OF ATLANTIC COASTAL PLAIN AQUIFERS, AIKEN COUNTY, SOUTH CAROLINA

Groundwater pumped from the Atlantic Coastal Plain (ACP) aquifers meets most of the potable and irrigation demands for Aiken County, but a comprehensive assessment of groundwater-quality conditions for Aiken County does not exist. This lack of an assessment of groundwater-quality conditions, even basic indicators such as pH, temperature, and dissolved oxygen, precludes County water managers and others from making informed decisions about where to place new wells (e.g., avoid areas where groundwater may contain high iron or radium isotope concentrations), how deep to drill wells, and what depth intervals should be screened to avoid in-well mixing of groundwater of different reduction/oxidation (redox) characteristics. As such, a comprehensive compilation of groundwater-quality data for Aiken County would be useful to water managers that want to minimize costs associated with groundwater treatment or others interested in groundwater quality. In Fiscal Year 2015 the U.S. Geological Survey (USGS), in cooperation with Aiken County, Breezy Hill Water and Sewer Company, Inc., Gilbert-Summit Rural Water District, and Montmorenci-Couchton Water and Sewer District, started a 3-year project to investigate the availability of the groundwater resources of Aiken County. A major component of the project is to develop a groundwater-flow model of the ACP beneath Aiken County. Because groundwater availability is dependent upon water quality and water-quality characteristics can be useful during model calibration, the study will provide these data in two ways. First, existing water-quality data will be compiled, and second, we will sample multiple public-supply wells across the County for basic physical properties and chemical composition of the groundwater. At select wells, additional water-quality parameters, such as inorganics, radionuclides, and volatile organic compounds, also will be sampled and analyzed.