Volatile organic compounds in the nation’s ground water and drinking-water supply wells

This report is one of a series of publications, The Quality of Our Nation’s Waters, that describe major findings of the National Water-Quality Assessment (NAWQA) Program on water-quality issues of national and regional concern. This report is on volatile organic compounds (VOCs) in ground water and drinking-water supply wells. It is a synthesis of NAWQA and other investigations. Fifty-five VOCs are emphasized in NAWQA’s field studies, and these compounds are the focus of this report. During NAWQA’s first decade of Study-Unit investigations, samples from more than 2,500 wells were analyzed for VOCs. In addition, carefully selected VOC data from more than 1,700 well samples were compiled from other agencies or collected in other USGS studies. Collectively, these VOC analyses are the basis for this report’s assessment, which is (1) the first national assessment of a large number of VOCs in the Nation’s aquifers and (2) the most recent national characterization of VOCs in samples from domestic and public wells used for drinking water.