Senior Principal Remediation Scientist
Mr. Evan Cox is a senior principal remediation scientist at Geosyntec Consultants with more than 25 years of demonstrated experience in the development and application of innovative in situ remediation technologies for chlorinated and energetic chemicals in subsurface environments. Mr. Cox has been the Principal Investigator for 4 SERDP and 5 ESTCP projects since 2000. Two of these projects won SERDP’s Cleanup Project-of-the-Year Award for Environmental Restoration (ER-1164 in 2001 and ER-1557 in 2010). Mr. Cox has been actively involved in development, demonstration and validation of novel in situ electrokinetic techniques to treat chlorinated solvent source areas in low permeability and heterogeneous materials. These techniques, referred to as Electrokinetic Bioremediation (EK-BIO) and Electrokinetically-delivered, Thermally-Activated Persulfate (EK-TAP) are the subjects of two of Mr. Cox’s ESTCP projects (ER-201325 and ER-201626 respectively).
Effective Treatment of Chlorinated Solvents in Clay and Silt Using Electrokinetic Techniques
Contaminants in clays and silts are long-term sources of pollutants to groundwater, requiring costly remediation and monitoring over many decades. Significant advances have been made in the past few years in the area of electrokinetically (EK) enhanced amendment delivery to treat contaminant source areas in low permeability and highly heterogeneous subsurface materials. EK is an innovative approach that uses electrokinetic mechanisms to promote the migration of amendments through clays/silts through electromigration, electroosmosis and/or electrophoresis. EK approaches are not dependent on hydraulic conductivity and can therefore achieve uniform and rapid distribution of amendments in clays and silts. Amendments can include electron donors (e.g., lactate), electron acceptors (e.g., nitrate), and/or microorganisms (e.g., Dehalococcoides, Dehalobacter) for in situ bioremediation (EK-BIO), or oxidants such as permanganate or thermally-activated persulfate for in situ chemical oxidation (EK-ISCO and EK-TAP, respectively). This presentation will discuss how and where these EK remediation technologies work in addition to providing in-depth results from a recently completed successful ESTCP demonstration/validation project of the EK-BIO technology to treat a tetrachloroethene (PCE) source area in clay at Naval Air Station Jacksonville, Florida (NAS-JAX; ESTCP ER-201325).