I study biodegradation of groundwater contaminants. Presently I serve as research coordinator of a team studying a 1979 crude oil spill at the USGS study site near Bemidji, Minnesota. Studies at the site include the fate and bioeffects of oxyhdrocarbons formed during natural attenuation, controls on degradation rates, and use of biogenic heat to estimate degradation
EDUCATION
University of California, Santa Cruz, Ph.D., 1993, Hydrogeology
San Jose State University, M.S., 1988, Mathematics
University of California, Los Angeles, B.A., 1975, Mathematics
EXPERIENCE
1990-present: Research Hydrologist, U.S. Geological Survey, Water Resources Division
2006-2008 Instructor, Stanford University, Solute Transport in Groundwater
1988-1993: Researcher and Instructor, University of California, Santa Cruz.
1979-1987: Computer Specialist, U. S. Geological Survey, Seismology Branch.
Project chief, system administrator and UNIX consultant for computer facilities monitoring earthquakes in real time.
1977-1978: Research Assistant, Stanford University Geophysics Department.
1976-1977: Mathematics Lab Director, Canada Community College.
1975-1976: Scientific Programmer, SRI International.
HONORS
Member, National Academy of Engineering, 2020
AGU Fellow, 2019
GSA Fellow, 2005
GSA Hydrogeology Division Birdsall-Dreiss Lecturer, 2003-2004
U.S. Geological Survey Meritorious Service Award, 2004
JOI/USSAC Distinguished Lecturer, 2002-2003
ARCS Foundation Fellowship, 1989-1990
University of California Regents’ Fellowship, 1988-1989
B.A. Summa Cum Laude, Phi Beta Kappa
INTERNATIONAL OCEAN DISCOVERY PROGRAM PARTICIPATION
Exp. 366, Mariana Serpentine Mud Volcanoes, 12/2016-2/2017, Downhole Tools and Phys. Props.
Science Planning Committee, 2004-2007.
Leg 201, Peru Deep Biosphere, 1/2002-4/2002, Downhole Tools and Phys. Props.
U.S. Science Advisory Committee, 2000-2003.
Science Steering and Evaluation Panel, Earth's Environment, 1997-2000.
Leg 171A, Logging While Drilling, 12/1996-1/1997, Hydrologist.
Sedimentary and Geochemical Processes Panel, 1994-1996.
COMMITTEES
AGU Program Committee, 2013-2016
AGU Groundwater Technical Committee, Chair 2009-2010
National Research Council Panel on Intrinsic Remediation, 1997-2000.
JOURNAL EDITORIAL BOARDS
Groundwater Monitoring and Remediation 2021-present.
Geofluids, 2007-2017.
Hydrogeology Journal, 1997-2000.
Ground Water, 1998-2003.
Geology, 1995-1998.
Science and Products
National Crude Oil Spill Fate and Natural Attenuation Research Site near Bemidji, Minnesota
Variability in Composition of an Oil Spill after more than 30 Years of Natural Attenuation
U.S. Geological Survey Identifies Crude-Oil Metabolites in Subsurface Plumes
Ethanol-Containing Fuel Spills Enhanced Natural Trace Element Release from Sediments in an Experimental Setting
Pipeline Crude Oil Spill Still a Cleanup Challenge after 30 Years
Understanding Fluid Injection Induced Seismicity
Science and Products
- Science
National Crude Oil Spill Fate and Natural Attenuation Research Site near Bemidji, Minnesota
The primary focus of the science team at the site is to improve the understanding of the mobilization, attenuation, transport, fate, potential health effects, and remediation of petroleum in the subsurface through collaborative research, peer-reviewed publications, presentations, data, and educational activities.Variability in Composition of an Oil Spill after more than 30 Years of Natural Attenuation
More than thirty years after an oil spill, hydrocarbons measured in groundwater near Bemidji, Minnesota, have been depleted between 25 and 85 percent. However, some components have remained for many decades and some are expected to remain longer indicating that natural attenuation is an effective but slow process. Compounds that are sufficiently soluble and resistant to biodegradation provide a...U.S. Geological Survey Identifies Crude-Oil Metabolites in Subsurface Plumes
U.S. Geological Survey (USGS) scientists studying two subsurface crude-oil spill sites in Minnesota measured concentrations of oil breakdown products (metabolites) at greater concentrations than parent compound concentrations.Ethanol-Containing Fuel Spills Enhanced Natural Trace Element Release from Sediments in an Experimental Setting
Experimental field research simulating hydrocarbon spills by researchers from the U.S. Geological Survey (USGS), Virginia Tech, and the University of St. Thomas showed that mixed ethanol and petroleum-based fuels increased the rate by which arsenic and other natural trace elements are released from aquifer sediments to groundwater when compared to petroleum-based fuels alone.Pipeline Crude Oil Spill Still a Cleanup Challenge after 30 Years
Research at a 1979 crude oil spill from a ruptured pipeline has exposed and helped to overcome many challenges facing an effective, cost-efficient cleanup of crude oil, U.S. Geological Survey (USGS) scientists have found. The environmental release of crude oil occurred near Bemidji, Minnesota.Understanding Fluid Injection Induced Seismicity
Fluid injection induced seismicity has been reported since the 1960s. There are currently more than 150,000 injection wells associated with oil and gas production in 34 states in the conterminous US. Pore pressure disturbance caused by injection is generally considered the culprit for injection induced seismicity, but, not all injection causes seismicity. It is not well understood what mechanical - Data
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