ORD Groundwater Research

Permeable Reactive Barrier (PRB)

Research includes 1) Laboratory and field based studies of geochemical, hydrogeological, and microbiological factors influencing the performance of PRBs; 2) PRB strategies for long-term performance monitoring for treatment of inorganic and organic contaminants in ground water; and 3) Use of alternate media PRBs to remediate ground water contamination

Rick Wilkin, wilkin.rick@epa.gov

Thermal Remediation

Applied research to evaluate the efficiency of thermal technologies on dense nonaqueous-phase liquid (DNAPL) mass removal including investigating abiotic degradation and reaction product formation of tricholoroethylene (TCE) when heated. 

Eva Davis, davis.eva@epa.gov

Nanotechnology

EPA researchers are involved in three areas of nanotechnology research: 1) Use of emulsified zero-valent iron (EZVI) for ground water remediation to decrease the mass flux of dissolved chlorinated solvents from a DNAPL source zone; 2) Evaluation of the fate and transport of nanomaterials (zero-valent copper, titanium dioxide, carbon onions, etc.) in porous media; and 3) Assessment of the chemical speciation and transformation (zerovalent iron), and antimicrobial activities of nanomaterials (copper and copper oxide) that may be released to ground and/or surface waters

Chunming Su, su.chunming@epa.gov

Monitored Natural Attenuation (MNA)

GWERD scientists have led the way in developing EPA's approach for applying and assessing monitored natural attenuation (MNA) as a cleanup tool for organic and inorganic contaminants in ground water. MNA can work with other more active remedial tools at some sites where biogeochemical conditions favor natural processes that degrade or immobilize harmful contaminants.

John Wilson, wilson.johnt@epa.gov
Rick Wilkin, wilkin.rick@epa.gov

In Situ Chemical Reduction

Research has included the use of a ferrous iron + sodium dithionite reductant solution blend to form in situ reactive zones capable of passively treating ground water contaminants, such as Cr(VI) moving through the reactive zone under natural gradient conditions. Other projects have included use of combined zero-valent iron + organic matter solid media in the form of a permeable reactive barrier to promote sulfate-reducing conditions in ground water and subsequent removal of metals and arsenic as secondary sulfide mineral phases.

Ralph Ludwig, ludwig.ralph@epa.gov; Chunming Su, su.chunming@epa.gov

In Situ Chemical Oxidation (ISCO)

EPA’s scientific investigations are on fundamental mechanisms involved in oxidation and reduction transformations.  Identifying and manipulating environmental conditions to minimize undesirable reactions contributing to process inefficiency and to facilitate favorable transformations.  Specifically, research is being conducted on persulfate (S2O82-) and its applied use at an increasing number of laboratories and field sites, resulting in the rapid development of this technology.

Scott Huling, huling.scott@epa.gov;
David Burden, burden.david@epa.gov

Gas and Vapor Intrusion (VI)

Currently, the research focus is to 1) determine relationship of radon to volatile organic compounds (VOC) concentrations at a given site.  Radon concentrations, if related, could be used as surrogate for vapor intrusion (VI) issues instead of the collection of VOC samples; 2) establish relationship between subslab/subsurface and indoor air concentrations of VOCs and possibly radon; 3) examine if near residence external samples could be used as surrogate sampling location to avoid in building “exploration” for potential VI; and 4) identify any seasonal fluxes in radon and VOC concentrations as they relate to the use of HVAC in the home or building.

Brian Schumacher, schumacher.brian@epa.gov  

Geophysics

Research includes 1) developing and evaluating new geophysical instruments and methods for detection and resolution of contaminants in shallow subsurface; 2) assessing technologies to monitor DNAPL remediation and assess long-term performance and effectiveness of MNA; and 3) investigating the geophysical response to surfactant enhanced aquifer remediation of chlorinated solvents.

D. Dale Werkema, werkema.d@epa.gov

Fuel Oxygenates

Research is being conducted to answer the questions about the behavior of gasoline if it should enter ground water: 1) Are the fuel oxygenates methyl tertiary butyl ether (MTBE) and TBA biologically degraded in ground water under natural conditions? 2) How can we determine the rate and extent of natural biodegradation at a spill site? And 3) How do the other oxygenates, such as ethanol, degrade under natural conditions?
Additional research is being done by EPA scientists on how well conventional remediation technologies work for treating MTBE fuel spills.

John Wilson, wilson.johnt@epa.gov
Cherri Adair, adair.cherri@epa.gov

Dense Nonaqueous-Phase Liquids (DNAPL) and Flux-Based Site Management

The uncertainty of restoration at sites where complete DNAPL depletion cannot be obtained is a key issue and EPA scientists have focused research on the use of a mass flux-based site management approach to assess NAPL source-zone treatment benefits.  Research is providing better methods to assess DNAPL sites; assessing partial DNAPL source removal benefits; and evaluating and improving mass flux measurement techniques.

Michael Brooks, brooks.michael@epa.gov;
Jungi Huang, huang.jungi@epa.gov;
Lynn Wood, wood.lynn@epa.gov

Combined Treatment Technologies

Research includes 1) ISCO and enhanced bioremediation: field demonstration, optimization and rigorous validation of peroxygen-based ISCO for the remediation of contaminated groundwater (ESTCP); 2) determining the contribution of abiotic processes to degrade chlorinated solvents in ground water; and 3) MNA of organic and inorganic contaminants.

Ann Keeley, keeley.ann@epa.gov

Groundwater –Surface water

Research includes the impact of groundwater/surface-water interactions on contaminant transport; provide technical resources for remedial site managers to define and assess the potential for use of site-specific natural processes to play a role in the design of an overall remedial approach to achieve cleanup objectives

Robert Ford, ford.robert@epa.gov

Groundwater Tech Support Center

Provides technical support including: 1) site characterization and remediation tools; 2) source zone remediation; 3) combined treatment technologies; and 4) PRBs.

David Burden, burden.david@epa.gov