Project Summary:

Uranium and ²²²radon are known contaminants in the Nation's ground waters, and there are increasing concerns about their occurrence in drinking water supplies. As part of the National Water-Quality (NAWQA) Program's effort to conduct regional aquifer assessments, this study is examining ground-water-quality data collected from 1,200 monitoring, public supply, and domestic drinking-water wells in glacial, Cambrian-Ordovician, and crystalline-bedrock aquifers during the Cycle I period (1991 to 2002) of the NAWQA Program. The overall objective is to evaluate regional geology and local-scale geochemical factors for their relation to natural uranium and ²²²radon concentrations in glacial and bedrock aquifers in the northern United States .This work will lead to a better understanding of the important controls at the regional scale on the presence and levels of uranium and ²²²radon in ground water. Aquifers that are likely to have high concentrations of uranium and ²²²radon will also be identified.

Preliminary results show that the highest concentrations of uranium occur in the western and central glaciated aquifers of the United States and in the crystalline-bedrock aquifers of New England and New Jersey. In this study, the highest concentrations of ²²²radon have occurred in the crystalline-bedrock aquifers of New England and New Jersey. A USGS scientific investigations report summarizing results from this study is planned to be completed late in 2006.