Examining the geologic link of arsenic contamination in groundwater in Orange County, NC

In recent decades, elevated arsenic concentrations in groundwater have been observed at various locations around the world including the Carolina terrane North Carolina. Orange County lies in the middle of the Carolina terrane and previous studies have observed arsenic concentrations in private well water samples that exceed the EPA drinking water standard of 10 ppb. This study uses a large database of arsenic concentrations and other water quality measurements in private water wells collected by the North Carolina Department of Health and Human Services and whole rock arsenic analysis to examine a possible geologic connection to elevated arsenic concentrations in groundwater. Through the use of geostatistical modeling and multivariate statistics, a hydrogeologic connection between certain water quality variables and detectable arsenic is found.