Volatile organic compounds in ground water in the Connecticut, Housatonic, and Thames River Basins, 1993-1995 [unknown]

Stephen J. Grady
1997 Fact Sheet   unpublished
Twenty-five volatile organic compounds (VOCs) were detected in water samples from 46 percent of wells in the Connecticut, Housatonic, and Thames River Basins NAWQA study area collected from July 1993 through September 1995. VOCs were detected in shallow monitoring wells (48 percent) screened in surficial aquifers and deeper, domestic-and institutional-supply wells (37 percent) completed in fractured bedrock. The gasoline additive MTBE was the most commonly detected VOC, followed by chloroform
more » ... wed by chloroform (25 and 23 percent of wells, respectively). VOC detections in ground water are related to urban land use, and the frequency of VOC detections and the total concentration of VOCs in ground water increased with increasing population density. Concentrations of five VOCs exceeded the U.S. Enivronmental Protection Agency's Maximum Contaminant Levels or Lifetime Health Advisories, but most (64 percent) VOC detections were at low concentrations (less than 1.0 microgram per liter) and may originate from nonpoint sources. NATIONAL WATER-QUALITY ASSESSMENT PROGRAM The National Water Quality Assessment (NAWQA) Program of the U.S. Geological Survey is designed to describe current waterquality conditions for a large part of the Nation's ground-and surface-water resources, to describe how water quality is changing over time, and to improve our understanding of the natural and human factors that afffect water quality.
doi:10.3133/fs02997 fatcat:3qbgahfhqzfarj2panpikkb5ym