Principal Technical Consultant
DuPont Corporate Remediation Group
Dr. Erin Mack is a Principal Technical Consultant in the DuPont Corporate Remediation Group. She has worked for DuPont since 1999 as an expert in environmental microbiology, biodegradation, and mercury fate and transport. She currently serves as a technical resource and manages external research programs in these areas for DuPont. Dr. Mack has applied results from these external programs to design remedial strategies for mercury, chlorinated solvents, and nitroaromatic compounds in the field. She holds a B. S. in Biology from University of Puget Sound, a M. A. in Microbiology from Southern Illinois University at Carbondale, a Ph. D. in microbiology from the University of California at Davis and was an NRC fellow at the USEPA laboratory in Athens, GA before joining DuPont.
SESSION KEYNOTE PRESENTATION
1,4 Dioxane Remediation - Where We Are, Where We're Going and What We Need
1,4 dioxane is an increasingly common groundwater contaminant, often present in dilute plumes and co-located with chlorinated solvents. The physicochemical properties of 1,4 dioxane make it difficult to treat efficiently through the well-developed strategies that target chlorinated solvents. In the U.S. there is no promulgated federal Maximum Contaminant Limit for 1,4 dioxane, and relatively few states have promulgated guidelines for drinking water and groundwater. The USEPA drinking water screening level is 0.47 μg /l, while state guidelines range from 0.4 to 200 μg/l and are frequently changing. This variability makes it difficult for site owners to develop remedial action objectives for groundwater, and to understand their stake in remediating it. Currently there is a toolbox of aggressive technologies for treatment of 1,4 dioxane typically involving the application of ex situ advanced oxidation processes. However, there is ample evidence that 1,4 dioxane is biodegradable and published studies documenting attenuation of 1,4 dioxane plumes indicating that natural attenuation or engineered biodegradation systems are potentially effective and protective remedial strategies. To date, natural attenuation has not been widely accepted as a remedial strategy for this compound and biodegradation remedies are only now being explored in the field. A deeper understanding of the microbial diversity and physiologies of 1,4 dioxane degrading organisms will help strengthen lines of evidence for natural attenuation and foster the design of engineered systems where biodegradation and physical treatments may be combined to result in effective sustainable strategies for treatment of this compound.
Co-Author: Claudia Walecka-Hutchison, DOW