USGS Groundwater Information: Branch of Geophysics
John W. Lane, Jr.
U.S. Geological Survey
Office of Ground Water, Branch of Geophysics
11 Sherman Place, Unit 5015
Storrs, CT 06269
Time-lapse monitoring of subsurface processes is an emerging and promising area of hydrogeophysics. The use of non-invasive or minimally invasive geophysical methods to indirectly measure time-varying fluid saturation, solute concentration, and other hydraulic and geochemical conditions facilitates cost-effective aquifer characterization and remediation. The USGS Office of Ground Water, Branch of Geophysics, in cooperation with USEPA, DOD, and university researchers, has applied time-lapse geophysics for site characterization and remediation monitoring at a number of sites. This talk presents recent examples of applied research, including: (1) application of cross-borehole and surface-to-borehole radar methods to monitor vegetable-oil emulsion injections for biostimulation at a Navy site in Fridley, MN; (2) application of borehole and cross-borehole radar methods to monitor steam injections for remediation of VOCs at the former Loring Air Force Base, ME; (3) application of electrical resistivity tomography to monitor saline tracer tests at the Massachusetts Military Reservation, MA; (4) use of borehole and cross-borehole flowmeter methods and a discrete-zone packer system to characterize bedrock aquifer hydraulics and water quality at the University of Connecticut landfill, Storrs, CT; and (5) application of crosshole radar methods to monitor a saline tracer in fractured bedrock at the USGS Mirror Lake Site, NH. The goals of these studies are (1) to provide increasingly quantitative information about the subsurface, critical for developing models of aquifer structure, dynamics, and processes, and (2) identification of the spatial and temporal distributions of tracers, contamination, and fluids injected to enhance degradation of contaminants.
Final copy as submitted to Eos Transactions for publication as: Lane, J.W., Jr., 2003, Time-lapse geophysics for aquifer characterization and remediation monitoring [abs.]: Eos Transactions, American Geophysical Union, v. 84, no. 46, Fall Meeting Suppl., Abstract H21F-01.