Dr. DiFilippo has extensive experience addressing the fate and transport of organic and inorganic chemicals in the environment. She has conducted numerous studies of groundwater transport, statistical geochemical analysis, groundwater age-dating, dense non-aqueous phase liquid (DNAPL) dissolution, enhanced DNAPL remediation technologies, and the use of innovative technologies for measuring in-situ concentrations of organic contaminants in sediment pore-water. For geochemical studies, she has applied various statistical methods to evaluate background concentrations, the impact of site activities on groundwater contaminants and RCRA compliance.

Dr. DiFilippo developed a censored multiple regression approach to allow for evaluation of long-term temporal trends when non-detects (i.e., censored data) are present and when predictable site-specific factors, such as groundwater-surface water interactions, are associated with or may cause concentration changes. Dr. DiFilippo has extensive experience coding in R and LaTeX and has developed several R packages for data processing and analysis.

An active member of the Per- and Polyfluorinated Alkyl Substances (PFAS) team with the Interstate Technology Regulatory Council (ITRC), Dr. DiFilippo has contributed to the Physical and Chemical Properties and Fate and Transport sections of the main document and its associated fact sheets. She also provided support for ITRC’s web-based PFAS expert roundtables. Dr. DiFilippo has worked with the National Ground Water Association’s (NGWA) PFAS working group. She is also a contributor to the ITRC team on Performance-Based Optimization of Pump & Treat Systems and authored sections of the document pertaining to methods for evaluating pump-and-treat performance.

EDUCATION
  • PhD, Hydrology and Water Resources (Minor in Soil, Water and Environmental Science), University of Arizona, 2008
  • MS, Earth Sciences, University of Southern California, 2004
  • BA, (Honors), Geology, Smith College, 2000
AREAS OF EXPERTISE
  • Geochemistry
  • Contaminant Fate and Transport
  • Groundwater Hydrology
  • Statistics
  • Monitored Natural Attenuation
  • Emerging Contaminants (PFAS)
  • Instrumental Analysis
AWARDS AND HONORS
  • Keith E. Anderson Award, National Ground Water Association: 2021
  • National Ground Water Association (NGWA) Scientists and Engineers Section Board Director, Elected (January 2015–December 2019, and January 2024–December 2026)
  • NIEHS Basic Research Program Graduate Trainee: The Southwest Hazardous Waste Program, University of Arizona. August 2006 and August 2007
  • Pacific Northwest National Laboratory Summer Research Institute Fellowship in Interfacial and Condensed Phase Chemical Physics: Summer 2005
  • Research Grant, The City of Palos Verdes, CA: November 2004
  • Sonosky Fellowship: University of Southern California. July 2003
  • Gundaker Foundation Graduate Grant: Rotary International District 7450. July 2003
  • Graduate Student Grant: University of Southern California. April 2002
  • Research Grant: The City of Palos Verdes, CA. March 2002
  • University of Southern California, Honorable Mention – Outstanding Teaching Assistant: Spring 2002
  • University of Southern California, Keck Fellowship: May 2001
  • Smith College, Keck Geology Consortium Undergraduate Research Fellowship: April 1999
APPOINTMENTS
  • 2022: Associate Editor, Ground Water
PROFESSIONAL SOCIETIES

National Ground Water Association (NGWA):

  • Government Affairs Committee Member: 2018–present
  • Regional Policy Committee – Eastern Region Chair: 2019–present
  • PFAS Working Group: 2020–present
  • Education and Awareness Subcommittee (Member: 2017–2018, Chair: 2018–2019)

American Geophysical Union (AGU):

  • AGU Annual Meeting Convener, Physical, Chemical and Biological Processes Controlling NAPL Source Zone Remediation: December 2008

Interstate Technology Regulatory Council (ITRC):

  • ITRC Performance-Based Optimization of Pump and Treat Systems Team Member: 2020–present
  • ITRC PFAS Team Member: 2018–present

Sigma Xi (Scientific Research Honor Society)

REPRESENTATIVE EXPERIENCE
Geochemical and Hydrogeological Evaluation of Former Yerington Mine Site2024-11-21T23:17:10+00:00

Geochemical and Hydrogeological Evaluation of Former Yerington Mine Site

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Geochemical Analysis of Sources and Mechanisms of Groundwater Recharge, Saugus Formation2024-11-21T16:45:14+00:00

Geochemical Analysis of Sources and Mechanisms of Groundwater Recharge, Saugus Formation

CenterPoint Oakland2024-11-21T17:02:07+00:00

CenterPoint Oakland

Managed Aquifer Recharge Geochemical Evaluations in Basalts2024-11-21T17:28:39+00:00
Columbia River Gorge

Managed Aquifer Recharge Geochemical Evaluations in Basalts

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EPA Region 5 Hydrogeological Synthesis and Numerical Modeling Support2024-11-21T17:33:12+00:00
Map of SSP&A's current and past projects for EPA Region 5

EPA Region 5 Hydrogeological Synthesis and Numerical Modeling Support

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PFAS Contamination in the Alabama River System2024-11-21T17:41:43+00:00
Historic Edmund Pettus Bridge, Selma, Alabama (stock image preview)

PFAS Contamination in the Alabama River System

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Agricultural Aquifer Storage and Recovery Geochemical Modeling2024-11-21T17:44:16+00:00
Scenic tomato field in California's Central Valley

Agricultural Aquifer Storage and Recovery Geochemical Modeling

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West Lake Landfill Site2024-11-21T17:46:08+00:00
West Lake Landfill Site RIM Figure

West Lake Landfill Site

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Coronet Industries Alternative Site2024-11-21T17:48:26+00:00
Coronet Industries Site – Main Plant and Pond 1S

Coronet Industries Alternative Site

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Sparton Technology Remediation2024-11-21T17:55:18+00:00
Sparton Technology Remediation

Sparton Technology Remediation

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The City of Muscle Shoals, Alabama, et al. v. 3M Company, et al.2024-11-21T18:09:00+00:00
Wilson Dam

The City of Muscle Shoals, Alabama, et al. v. 3M Company, et al.

Hanford Site: Groundwater Modeling2024-11-21T18:15:38+00:00
Hanford Groundwater Model figure

Hanford Site: Groundwater Modeling

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Former Halliburton Manufacturing Facility2024-12-10T20:06:06+00:00
Hydraulic Gradients with Time

Former Halliburton Manufacturing Facility

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PUBLICATIONS & PRESENTATIONS

  • E. DiFilippo, C. Andrews, B. Hoagland, G. Davis, 2024. Polymer based PFAS as long-term source to surface water in the Alabama River System. Presented at the National Ground Water Association’s Groundwater in the PFAS Era conference, Tucson, AZ, April 16.

  • DiFilippo, E., M. Tonkin and W. Huber, 2023. Use of Censored Multiple Regression to Interpret Temporal Environmental Data and Assess Remedy Progress. Groundwater, vol 61, no. 6: 846-864. doi: 10.1111/gwat.13315

  • Guo, Z., A.E. Russo, E.L. DiFilippo, Z. Zhang and M.L. Brusseau, 2020. Mathematical Modeling of Organic Liquid Dissolution in Heterogeneous Source Zones. Journal of Contaminant Hydrology, v. 235. doi: 10.1016/j.jconhyd.2020.103716

  • DiFilippo, E., M. Tonkin, A. Spiliotopoulos, W. Huber and V. Rohay, 2019. Evaluating Environmental Remediation Performance at Radwaste Sites Using Multiple, Censored Regression Analysis. WM2019 Conference Proceedings, March 3-7, 2019. 15 pp.

  • Spiliotopoulos, A., E. DiFilippo, P. Khambhammettu, D. Hayes, M. Tonkin, M. Hartman, K. Ivarson, J. Hulstrum, 2019. Web-Assisted Methods and Tools for Efficient Remedy Design and System Performance Evaluation at Hanford. WM2019 Conference Proceedings, March 3-7, 2019. 15 pp.

  • DiFilippo, E., M. Tonkin, and W. Huber, 2018. Multiple, Censored Regression Analysis for Evaluating Remediation Performance. AGU Fall Meeting Abstracts. December 2018.

  • Eganhouse, R.P., E.L. DiFilippo, J. Pontollilo, W. Orem, P. Hackley, B.D. Edwards, 2018. DDT and Related Compounds in Pore Water of Shallow Sediments on the Palos Verdes Shelf, California, USA. Marine Chemistry, v. 203, pp. 78-90. doi: 10.1016/j.marchem.2018.05.003

  • Eganhouse, R.P. and E.L. DiFilippo, 2015. Determination of 1-chloro-4-[2,2,2-trichloro-1-(4-chlorophenyl)ethyl]benzene and Related Compounds in Marine Pore Water by Automated Thermal Desorption-gas Chromatography/Mass Spectrometry Using Disposable Optical Fiber. Journal of Chromatography A, v. 1415, pp. 38-47. doi: 10.1016/j.chroma.2015.08.060

  • Eganhouse, R.P., J. Pontolillo, B.D. Edwards, E.L. DiFilippo, W.H. Orem, S. Qin, G. Hopkins, and M. Reinhard, 2012. Porewater Chemistry of DDT Compounds in Sediments of the Palos Verdes Shelf, CA and its Relevance to Natural Attenuation Processes. Abstracts of Papers of the American Chemical Society. March 2012.

  • DiFilippo, E.L., and M.L. Brusseau, 2011. Application of Light Reflection Visualization for Measuring Organic-Liquid Saturation for Two-Phase Systems in Two-Dimensional Flow Cells: Environmental Engineering Science, v. 28, no. 11, pp. 803 – 809. doi: 10.1089/ees.2010.0471

  • DiFilippo, E. and M. Brusseau, 2011. Assessment of a Simple Function to Evaluate the Relationship Between Mass Flux Reduction and Mass Removal for Organic-Liquid Contaminated Source Zones. Journal of Contaminant Hydrology, v. 123, no 3-4, pp. 104-113. doi: 10.1016/j.jconhyd.2010.12.011

  • DiFilippo, E., and R. Eganhouse, 2010. Assessment of PDMS-Water Partition Coefficients: Implications for Passive Environmental Sampling of Hydrophobic Organic Compounds. Environmental Science & Technology, v. 44, no. 18, pp. 6917-6925. doi: 10.1021/es101103x

  • DiFilippo, E., K. Carroll, and M. Brusseau, 2010. Impact of Organic-Liquid Distribution and Flow-Field Heterogeneity on Reductions in Mass Flux. Journal of Contaminant Hydrology, v.115, no. 1-4, pp. 14-25. doi: 10.1016/j.jconhyd.2010.03.002

  • DiFilippo, E.L. and R.P. Eganhouse, 2009. Assessment of SPME Partitioning Coefficients: Implications for Passive Environmental Sampling of Hydrophobic Organic Compounds. AGU Fall Meeting Abstracts. December 2009.

  • DiFilippo, E.L. and M.L. Brusseau, 2008. Time-Continuous Analysis of Mass Flux Reduction as a Function of Source Zone Mass Removal at two Field Sites. National Ground Water Association (NGWA) 2009 Ground Water Summit, April 19-23, 2009.

  • Brusseau, M., E. DiFilippo, J. Marble, and M. Oostrom, 2008. Mass-Removal and Mass-Flux-Reduction Behavior for Idealized Source Zones with Hydraulically Poorly-Accessible Immiscible Liquid. Chemosphere, v. 71, no. 8, pp. 1511-1521. doi: 10.1016/j.chemosphere.2007.11.064

  • DiFilippo, E.L., and M. Brusseau, 2008. Relationship between Mass-Flux Reduction and Source-Zone Mass Removal: Analysis of Field Data. Journal of Contaminant Hydrology, v. 98, no. 1-2, pp. 22-35. doi: 10.1016/j.jconhyd.2008.02.004

  • Marble, J., E. DiFilippo, Z. Zhang, G. Tick, and M. Brusseau, 2008. Application of a Lumped-Process Mathematical Model to Dissolution of Non-Uniformly Distributed Immiscible Liquid in Heterogeneous Porous Media. Journal of Contaminant Hydrology, v. 100, no. 1-2, pp. 1-10. doi: 10.1016/j.jconhyd.2008.04.003

  • DiFilippo, E.L. and M.L. Brusseau, 2007. Field Scale Investigation of Mass Flux Reduction as a Function of Source Zone Mass Removal for Immiscible Liquid Contaminated Aquifers. Presentation at the U.S. Environmental Protection Agency’s Desert Remedial Action Technologies (D-RAT) Workshop, Phoenix, AZ, October 2-3, 2007.

  • DiFilippo, E.L., J.C. Marble, M. Oostrom, and M.L. Brusseau, 2006. Investigation of Mass Flux Reduction as a Function of Source Zone Mass Removal for Immiscible Liquid Contaminated Aquifers. Presentation at the National Institute of Environmental Health Sciences (NIEHS) S. Basic Research Program (SBRP) Annual Meeting, December 2006.

  • Marble, J., E. DiFilippo, A. Russo, Z. Zhang, and M. Brusseau, 2006. Dissolution and Mass Flux Dynamics of Immiscible Liquids in Heterogeneous Media. AGU Fall Meeting Abstracts, December 2006.

  • DiFilippo, E.L., M.L. Brusseau, M. Oostrom, and T.W. Wietsma, 2005. Experimental Investigation of DNAPL Mass Flux Reduction as a Function of Source Zone Mass Removal. AGU Fall Meeting Abstracts. December 2005.

  • DiFilippo, E.L., D.E. Hammond, R. Douglas, J.F. Clark, D. Avisar, and R. Dunker, 2004. Utilizing Tritium and CFC-12 to Determine Groundwater Sources in an Unconfined Aquifer within the Abalone Cove Landslide, Palos Verdes, California. AGU Fall Meeting Abstracts, December 2004.

  • DiFilippo, E., D. Hammond, and F. Corsetti, 2003. Geochemical Constraints for Coexisting CO2 Gas Hydrate and Calcite: Implications for Sheet Cracks, Stromatactis, Zebra and Teepee-Like Structures. Sedimentary Geology, v. 160, no. 1-3, pp. 1-6. doi: 10.1016/S0037-0738(03)00152-0

  • DiFilippo, E.L., 2000. Metamorphic Evolution of High-Pressure, Low-Temperature Mafic Rocks Near Kini on the Island of Syros, Greece. Presentation at the 13th Keck Research Symposium in Geology, Beloit College, WI, pp. 24-27.

  • Cheney, J.T., J.C. Schumacher, C.D. Coath, J.B. Brady, E.L. DiFilippo, E.N. Argyrou, J.W. Otis, A.J. Sperry, J.E. Sable, and P.A. Skemer, 2000. Ion Microprobe Ages of Zircons from Blueschists, Syros, Greece. in Geological Society of America Abstracts with Programs. 32.

  • DiFilippo, E. L., and J. B. Brady, 2000. Metamorphic Evolution of High-Pressure, Low Temperature Mafic Rocks near Kini on the Island of Syros, Greece. in: The Geological Society of America, Northeastern Sectional Meeting, Abstracts with Programs. 23.