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D. Dale Werkema, Jr., Ph.D.

My work is focused on understanding the geophysical response to active or passive remediation and subsurface contamination. This work Includes the biogeochemical alterations in the subsurface due to contamination and remediation.  Understanding the geophysical response then guides geophysical method development, geophysical monitoring, and the characterization of subsurface contamination and remediation efforts.  These applications increase the knowledge of the contaminant distribution and the effectiveness of the remediation using non-intrusive, or minimally intrusive geophysical methods.

Biographical Information

Name: D. Dale Werkema, Jr.
Title:   Research Geophysicist

Contact Info:

Environmental Sciences Division / Characterization and Monitoring Branch
U.S. Environmental Protection Agency
P.O. Box 93478
Las Vegas, Nevada 89193

Phone: 702-798-2263


  • Ph.D. in Geology, emphasis Geophysics, 2002, Western Michigan University (WMU)
      Dissertation Title: Geoelectrical Response During Microbial LNAPL Degradation: Implications for Monitoring Bioremediation.
  • M.S. in Geology, emphasis Geophysics, 1998, WMU
      Thesis Title: A Generic Automated / Semi-Automated DC Resistivity Field Data Acquisition System
  • B.S. in Geology, 1995, Wayne State University
      Undergraduate research project investigated the microscopy of heavy minerals as related to source rocks

Professional Experience

  • Research Geophysicist, U.S. EPA, NERL, ORD, ESD-LV, 2005 – Present
  • Adjunct Professor, Western Michigan University (WMU), 2013 – Present
  • Characterization and Monitoring Branch (CMB), Acting Branch Chief, NERL, ORD, ESD-LV, Jul. 2008 - Mar. 2010
  • Post-Doctoral Research Scientist, U.S. EPA, NERL, ORD, ESD-LV.  2002 – 2005
  • Visiting Assistant Professor of Geologic and Environmental Sciences, Hope College 2001 – 2002
  • Principal Geophysicist, Geophysical Services International, L.L.C., December 1998 – August 2002
  • Research Assistant/Instructor, Department of Geosciences, Western Michigan University, 1997– 2000

Awards and Honors:

  • 2013, Best of SAGEEP 2013 Award for the presentation, “Biogeochemical controls on magnetic susceptibility variations across a hydrocarbon contaminated site”
  • 2011, US EPA ORD Honor Award:  Exceptional/Outstanding ORD Technical Assistance to the Regions or Program Offices:  In recognition of exemplary technical assistance provided to the Regions and Program offices in the field of Geophysics.
  • 2011, USEPA Superior Accomplishment Recognition Award for the publication of two peer reviewed journal articles, two presentations at international meetings, and the U.S. EPA Environmental Geophysics Web Site and Geophysical Decision Support System
  • 2010, USEPA Award in recognition of services as Acting Branch Chief
  • 2010, U.S. EPA Superior Accomplishment Recognition Award for the completion of the EPA Report “A Feasibility Study on the Geophysical Response to Nanoparticles in the Subsurface
  • 2009, USEPA Awards for: Technical Assistance to the Regions; ESD Peer Review Performance; Branch Assistance award; Leadership in the Environmental Geophysics Research Program; and, Quality Assurance Excellence
  • 2009-2012 Environmental and Engineering Geophysical Society (EEGS) Board of Directors, At-Large Member, an elected position within EEGS
  • 2007, U.S. EPA TwoAwards of Excellence
  • 2003 - 2006, U.S. EPA Superior Accomplishment Recognition Award
  • 2000, Best Student Paper Award for "Vertical Distribution of Microbial Abundance's and Apparent Resistivity at an LNAPL Spill Site", Symposium on the Applications of Geophysics to Environmental and Engineering Problems (SAGEEP 2000), Washington, DC.

Publications and Presentations (1999 - Present) / (These are from ORD Science Inventory) 

Select Presentations:


Atekwana, E., G. Abdel Aal, AND D. Werkema. Detection of Silver Nanoparticles in Vadose Zone Environments using Complex ConductivityMeasurements. Presented at 20th European Meeting of Environmental and Engineering Geophysics, Athens, GREECE. September 14 - 18, 2014

Invited by the Environmental Protection Agency Taiwan (EPAT) to conduct a workshop on Environmental Geophysics.  This invitational international travel included several presentations, several field site visits and demonstrations.  It was funded by EPAT through the American Institute in Taiwan (AIT).  May 16 – 26, 2014


Atekwana,E.A., Mewafy, F., Abdel Aal, G., Atekwana, E., Beaver, C., Rossbach,S., Slater, L., Ntarlagiannis,D., Revil, A., and Werkema, D., Biogeochemical controls on magnetic susceptibility variations across a hydrocarbon contaminated site, European Association of Geoscientist and Engineers – Near Surface Geophysics (EAGE-NSG) in Bochum Germany, August 9-12, 2013. Invited presentation


Slater, L, Atekwana, A, Revil, A, Mewafy, F., Bekins, B., Cozzarelli, I.,  Herkelrath, W., Skold, M., Ntarlagiannis, D., Trost, J., Erickson. M., Heenan, J., Lane, J.W. Jr. and D. Werkema, Field scale evidence for biogeophysical signatures resulting from natural attenuation of a well characterized crude oil spill, American Geophysical Union Fall Meeting, December 2012.


Werkema, D., Magnetic Susceptibility Measurements as a Proxy for Hydrocarbon Biodegradation, the American Geophysical Union (AGU) Annual Meeting, Dec 2011

Werkema, D., Modeling and inversion Matlab algorithms for resistivity, induced polarization and seismic data, the American Geophysical Union (AGU) Annual Meeting, San Francisco, CA, Dec 2011

Werkema, D., Spectral Induced Polarization Signatures of Ethanol (EtOH) g in Sand-Clay Medium, the Second international Workshop on included Polarization in Near-Surface Geophysics, Golden, CO, Nov. 2011


Werkema, D., The Geophysical Response to Petroleum Hydrocarbons in the near subsurface, 2010 National Ground Water Association Petroleum Hydrocarbons and Organic Chemicals in Ground Water Forum, Dec 2010

Werkema, D., Spectral induced polarization signatures from a crude‐oil contaminated site undergoing biodegradation, Bemidji, MN, the American Geophysical Union (AGU) Annual Meeting, San Francisco, CA, Dec 2010

Werkema, D., Labortory Assessment of Nano-Silver Transport in Sand Columns Using Complex Conductivity Measurements, the Symposium on the Applications of Geophysics to Environmental and Engineering Problem, April 2010
Joyce, Ryan, Werkema, Dale, Atekwana, Estella, Atekwana, Eliot, Complex Conductivity Response to Nanomaterials in a Sand Matrix, American Geophysical Union (AGU) Fall 2008 meeting, San Francisco, CA, 2008

Magill, Meghan, Werkema, Dale, Kraemer, Dave, Spectral Induced Polarization Response of Unconsolidated Saturated Sand and Surfactant Solutions, American Geophysical Union (AGU) Fall 2008 meeting, San Francisco, CA, 2008

Davis, C.A., Pyrak-Nolte, L.J. Atekwana, E.A., Haugen, M.E., Werkema, D.D., Investigating the Effect of Microbial Growth and Biofilm Formation on Seismic Wave Propagation in Sediment, AGU Chapman Conference on Biogeophysics, Portland, Maine , October 13-16, 2008

Vukenkeng, C.A., Atekwana, E.A., Atekwana, E.A., Sauck, W.A., Werkema, D.D., Using geophysical signatures to investigate temporal changes due to source reduction in the subsurface contaminated with hydrocarbons, AGU Chapman Conference on Biogeophysics, Portland, Maine , October 13-16, 2008

Joyce, R., Vukenkeng, C., Atekwana, E., Atekwana, E., Werkema, D., Rossbach, S., Abdel Aal, G., Davis, C., Nolan, J., Temporal Geophysical Investigations of the FT-2 Plume at the Wurtsmith Air Force Base, Oscoda, Michigan, Proceedings of the Symposium on the Applications of Geophysics to Environmental and Engineering Problems, Philadelphia, PA, 2008


Werkema, D.D., Aqueous Physicochemical Property Changes in Aqueous Solutions due to Surfactant Treatment of PCE: Implications to Geophysical Measurement, American Geophysical Union Meeting, San Francisco, CA, 2007
Sauck, W.A., Atekwana E.A., Werkema, D.D., An updated model for the Anomalous Resistivity of LNAPL Plumes in Sandy Environments, American Geophysical Union Joint Assembly, Baltimore Maryland, May 2006
Werkema, D.D., Atekwana, E.A., Atekwana, E., Duris, J., Rossbach, S., Allen, J., Smart, L., Sauck, W.A., Laboratory and field results linking high conductivities to the microbial degradation of petroleum hydrocarbons, Proceedings of the Symposium on the Applications of Geophysics to Environmental and Engineering Problems 2004, Colorado Springs, CO.
Laura A. Sherrod, D. Dale Werkema, William A. Sauck, Estella A. Atekwana, Silvia Rossbach, and Eliot A. Atekwana;  Column experiments and anomalous conductivity in hydrocarbon-impacted sands; Eighth International Congress of the Brazilian Geophysical Society, Rio de Janeiro, Brazil, 2003

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