Minnesota Water Science Center
Minnesota PROJECTSABOUT THE Minnesota
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Project Title: Toxics - Crude Oil Contamination of Ground Water Near Bemidji
Statement of Problem:Many contamination problems result from the discharge and entrainment of liquid organic substances in ground water. Major expenditures are being made to minimize or alleviate the impact of such contaminants on the environment but detailed scientific understanding of processes in the subsurface is lacking. Spilled petroleum products are a major source of ground-water contamination. About 10,000 barrels of crude petroleum spilled from a broken pipeline near Bemidji, MN, on August 20, 1979. Although regulatory and remedial actions have been completed, as much as 4 feet of crude petroleum is floating on the water table in the outwash aquifer. Ground water is dissolving the oil, and residual organic compounds in the unsaturated zone are being leached downward. Objectives:Obtain a complete understanding of the mobilization, transport, and fate of petroleum derivatives in the subsurface and use this understanding to develop predictive models of contaminant behavior in the ground-water system. Relevance and Impact:Research results and expertise developed at the Bemidji Toxics Substances crude-oil research site have benefited Scientists and the public worldwide. Results have been transferred to many other sites of hydrocarbon contamination. The research team members receive numerous requests for information annually regarding research results from people outside USGS. The Bemidji project also receives many requests for information regarding research results through our web site. Through these contacts, research results and knowledge gained at the Bemidji Toxics site are transferred to the public. Progress and Significant Results: Fiscal Year 2008Researchers l continued investigating processes that influence water flow and transport of dissolved hydrocarbon contaminants from the unsaturated zone to ground water. Mayer and others (University of British Columbia) conducted a study focused on the investigation of ebullition of methane, carbon dioxide, and hydrocarbons across the capillary fringe. Amos and others (U. of Waterloo) conducted research focused on investigating the extent of methane oxidation in ground water. Bekins, Cozzarelli, and Voytek continued to analyze samples collected in the 2007 field season. This included microbial population analyses. Two types of data will provide estimates of the populations of the major groups of methanogens and iron-reducers in the area of active benzene degradation. Cozzarelli performed sediment iron extractions for cores collected from the location of maximum benzene degradation. Warren continued to determine temperatures in the aquifer at the Bemidji Site and how they relate to microbial activity and contaminants with respect to time and location. The research team of Nevin and Lovley took sediment samples and look for the expression of genes associated with degradation of aromatics Because remediation has ended, the effects of remediation on oil occurrence and hydrocarbon vapor transport were assessed. Delin made a presentation on research at the Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds in Monterey, CA. Statement of Work: Fiscal Year 2009Herkelrath and Delin will continue investigating processes that influence water flow and transport of dissolved hydrocarbon contaminants from the unsaturated zone to ground water at the Bemidji site. Mayer and others (University of British Columbia) will continue a study that focuses on the investigation of ebullition of methane, carbon dioxide, and hydrocarbons across the capillary fringe at the Bemidji site. Amos and others (U. of Waterloo) continue research investigating the extent of methane oxidation in the groundwater. Researchers Bekins, Cozzarelli, and Voytek will continue to analyze samples collected in the 2008 field season. |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://mn.water.usgs.gov/projects/description/86070KC.html
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