Predicting the occurrence of radon-222 in groundwater supplies

The intent of this study was to develop an understanding of some of the factors that affect the concentration of radon-222(222Rn) in drinking water supplies derived from groundwater, with specific application to North Carolina. Data for this investigation were collected on a sample of 96 North Carolina public water supply wells. Water samples were collected and analyzed for 222Rn content. Data on site geology and well characteristics (discharge, specific capacity, depth, and casing length) were obtained from existing sources. From a statistical examination of the data collected in this study, we conclude that there is a distinct and statistically significant difference in the mean 222Rn concentrations of groundwater associated with different types of rocks, also that there is a great degree of variability in the 222Rn concentrations of samples drawn from any given rock type. (author)