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The U.S. Geological Survey is investigating the impacts of oil and gas production on soils, groundwater, surface water, and ecosystems in the United States. Two sites in northeastern Oklahoma (sites A and B) are presently being investigated under the Osage–Skiatook Petroleum Environmental Research project. Oil wells on the lease surrounding site A in Osage County, Oklahoma, produced about 100,000 bbl of oil between 1913 and 1981. Prominent production features on the 1.5-ha (3.7-ac) site A include a tank battery, an oil-filled trench, pipelines, storage pits for both produced water and oil, and an old power unit. Site activities and historic releases have left open areas in the local oak forest adjacent to these features and a deeply eroded salt scar downslope from the pits that extends to nearby Skiatook Lake. The site is underlain by surficial sediments comprised of very fine-grained eolian sand and colluvium as much as 1.4 m (4.6 ft) thick, which, in turn, overlie flat-lying, fractured bedrock comprised of sandstone, clayey sandstone, mudstone, and shale. A geophysical survey of ground conductance and concentration measurements of aqueous extracts (1:1 by weight) of core samples taken in the salt scar and adjacent areas indicate that unusual concentrations of NaCl-rich salt are present at depths to at least 8 m (26 ft) in the bedrock; however, little salt occurs in the eolian sand. Historic aerial photographs, anecdotal reports from oil-lease operators, and tree-ring records indicate that the surrounding oak forest was largely established after 1935 and thus postdates the majority of surface damage at the site. Blackjack oaks adjacent to the salt scar have anomalously elevated chloride (>400 ppm) in their leaves and record the presence of NaCl-rich salt or salty water in the shallow subsurface. The geophysical measurements also indicate moderately elevated conductance beneath the oak forest adjoining the salt scar.
James Otton is project manager for studies of environmental impacts of oil and gas production on surficial systems. He received his B.S. degree and his Ph.D. from Penn State University. His current research interests include produced water brine and naturally occurring radioactive materials impacts on soils, groundwater, and surface waters. He is chair for the Science Advisory Board for the Integrated Petroleum Environmental Consortium.Robert Zielinski is a research geochemist who specializes in the areas of trace-element geochemistry, isotope geology, and radiochemistry. He received a B.A. degree in chemistry from Rutgers University and a Ph.D. in geochemistry from the Massachusetts Institute of Technology. His current research interests include studies of the mode of occurrence, dispersion, and environmental impact of salts and radionuclides introduced from oil and gas development.
Bruce Smith is a geophysicist specializing in ground and airborne subsurface electrical property measurements and imaging. He is currently developing and applying geophysical methods in studies of environmental impacts of energy and mineral resource development. He also specializes in developing programs in shallow groundwater quality mapping. His work has covered most of the United States and several foreign countries.
Marvin Abbott received his B.S. and M.S. degrees from Oklahoma State University. He worked as a petroleum geologist from 1978 to 1990. He is presently a hydrologist, with groundwater geochemistry and brines associated with oil and gas production as his principal interests. He has experience in geochemical modeling, aquifer testing, and geographical information system methods.
Bobby Keeland received a Ph.D. in ecology from the University of Georgia. His major research interests include ecology and restoration of forested wetlands of the southeastern United States, population and community ecology, dendroecology, primary production and decomposition processes, and hydrology.