Occurrence of volatile organic compounds in ground water in the White River Basin, Indiana, 1994–95

Water samples collected in 1994 and 1995 from 100 monitoring wells (91 shallow and 9 deep) screened in shallow unconsolidated aquifers in the White River Basin were analyzed for 58 volatile organic compounds (VOC’s). Twelve different VOC’s were detected. Chloroform was the most commonly detected VOC (found in 12 wells), whereas the highest measured VOC concentration was 39 micrograms per liter of 1,1-dichloroethane. No VOC had a measured concentration in ground water that exceeded a U.S. Environmental Protection Agency national drinking-water standard or guideline. Slightly more than fifty percent of the shallow wells in urban settings, as compared to six percent of the shallow wells in agricultural settings, had at least one VOC detected.