Geophysical Monitoring of a Biostimulation Pilot Study to Remediate Contaminated Ground Water, Fridley, Minnesota - FY2003

As part of its applied research initiatives in FY2003, the USGS Office of Ground Water, Branch of Geophysics continued to conduct geophysical experiments to monitor a U.S. Navy pilot biostimulation project to remediate groundwater contaminated with volatile organic compounds (VOCs) in Fridley, Minnesota.

Down-gradient from the Naval Industrial Reserve Ordnance Plant (NIROP), Fridley, Minnesota, areas contaminated by VOCs have been injected with vegetable oil to stimulate biodegradation as part of ongoing remediation efforts. As part of the remediation monitoring efforts, the Branch of Geophysics conducted geophysical surveys to characterize the spatial and temporal distribution of the injected vegetable oil and to estimate the emulsion saturation between the wells used for surveying.

During FY2003, Branch of Geophysics activities included geophysical field work as well as data analysis and processing. Field visits were made to collect borehole and surface-to-borehole geophysical data in order to continue tracking the migration of the vegetable-oil emulsion that had been injected into the ground by the US Navy. An innovative, object-based inversion method was developed for use in processing the cross-well data; this inversion method builds on understanding of the site's hydrologic and geologic characteristics in order to produce tomograms more immediately useful to engineers and hydrologists. Based on changes in the radar velocity data collected during surveys, models of the physical properties of the subsurface were developed in order to estimate how saturated the region is with vegetable oil emulsion. Data from one image plane also were analyzed to estimate the distribution of the vegetable oil emulsion and emulsion saturation. Data processing and analysis continued with the goal of providing images of changes in the distribution of oil over time. These images could be used to determine how the oil is moving through the ground and to determine if changes in subsurface electrical conductivity due to microbial activity or other factors can be monitored using borehole radar methods.

This work was funded by the US Navy, with support from the USGS Toxic Substances Hydrology Program.

This research was conducted by John W. Lane, Jr. (USGS OGW BG), Fred D. Day-Lewis (USGS OGW BG), and Alan Witten (Oklahoma University School of Geology and Geophysics), with assistance from OGW BG staff.

View the online photo gallery from this project.

Recent publications:

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.

Lane, J.W., Jr., Casey, C.C., Day-Lewis, F.D., Witten, A., and Versteeg, R.J., 2004, Use of borehole radar methods and borehole geophysical logs to monitor a field-scale vegetable oil biostimulation pilot project at Fridley, Minnesota, in Proceedings of the Fourth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 24-27, 2004, Monterrey California. Proceedings: Battelle Memorial Institute, CD-ROM, 9 pages.

Lane, J.W., Jr., Day-Lewis, F.D., Versteeg, R.J., and Casey, C.C., 2004, Object-based inversion of crosswell radar tomography data to monitor vegetable oil injection experiments: Journal of Environmental & Engineering Geophysics, vol.9, issue 2, p. 63-77.

Lane, J.W., Jr., Day-Lewis, F.D., Versteeg, R.J., Casey, C.C., and Joesten, P.K., 2004, Application of cross-borehole radar to monitor field-scale vegetable oil injection experiments for biostimulation, in Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), 22 to 26 February, 2004, Colorado Springs, Proceedings: Denver, Colorado, Environmental and Engineering Geophysical Society, CD-ROM, 20 p.

Lane, J.W., Jr., Day-Lewis, F.D., Versteeg, R.J., and Casey, C.C., 2003, Object-based inversion of crosswell radar tomography data to monitor vegetable-oil injection experiment, in Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), April 6-10, 2003, San Antonio, Texas, Proceedings: Denver, Colorado, Environmental and Engineering Geophysics Society, CD-ROM, 27 p.

Witten, A., and Lane, J., 2003, Offset vertical radar profiling: Leading Edge, v. 22, no. 11, p. 1070-1076.

For related information, see:

• Summary of OGW BG FY2002 research at Fridley site
• Summary of OGW BG FY2003 development of advanced radar processing methods