USGS Groundwater Information: Branch of Geophysics
Williams, John H. and Anderson, J. Alton, U. S. Geological Survey, 425 Jordan Road, Troy NY 12180
Borehole geophysics has provided critical information for investigations of groundwater contamination in fractured bedrock. The U.S. Geological Survey has applied borehole-geophysical methods at sites contaminated with volatile organic compounds (VOCs) and underlain by sedimentary and crystalline bedrock in the Northeast and California. These methods include gamma and induction logging; borehole imaging (acoustic and optical televiewer); and fluid-property logging (specific conductance and temperature), single- and cross-hole flowmeter testing (heat pulse and electromagnetic), and point sampling for VOCs under ambient and pumped conditions. Integrated analysis of the borehole geophysical logs helped to delineate lithology; correlate stratigraphic units; and define the distribution and orientation of bedding, foliation, and fractures. The analysis also helped to characterize the distribution of fracture-flow zones; quantify vertical flow between zones in open boreholes under ambient and pumped conditions; and estimate transmissivity, hydraulic head, and connectivity of the zones. The geohydrologic information gained through the application of borehole geophysics was useful for general site characterization and source identification as well as the design and evaluation of monitoring and remediation programs.
The presentation given for this abstract is available online from the U.S. Environmental Protection Agency Technical Support Project Semi-Annual Meeting (Niagara Falls, New York, October 20-23, 2003) web site.
Final copy as submitted to U.S. Environmental Protection Agency Technical Support Project Semi-Annual Meeting for publication as: Williams, J.H., and Anderson, J.A., 2003, Borehole geophysics for investigation of ground-water contamination in fractured rock [abs.], in U.S. Environmental Protection Agency Technical Support Project Semi-Annual Meeting, Niagara Falls, New York, October 20-23, 2003: U.S. Environmental Protection Agency, accessed February 4, 2004, at http://www.epa.gov/tio/tsp/download/2003_meeting_fall/williams_john_abstract.pdf