Scissortail Environmental Solutions LLC.
John Wilson has more than 40 years of experience dealing with biodegradation of hazardous organic compounds in ground water. For 36 years was a research microbiologist with the U.S. Environmental Protection Agency, where he was instrumental in developing the EPA’s approach for evaluating and applying Monitored Natural Attenuation to manage risk from hazardous chemicals in ground water at hazardous waste sites. At the time of his retirement, he was the leading EPA expert on MNA or bioremediation of organic compounds in ground water. He was the Project Officer and a coauthor on the USEPA Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water. He organized and edited the U.S. EPA report A Guide for Assessing Biodegradation and Source Identification of Organic Ground Water Contaminants using Compound Specific Isotope Analysis (CSIA). EPA 600/R-08/148. He was a coauthor of the U.S. EPA report Identification and Characterization Methods for Reactive Minerals Responsible for Natural Attenuation of Chlorinated Organic ‘Compounds in Ground Water.
Lines of Evidence Approaches in Remediation: What Have We Learned?
The lines of evidence approach for MNA was originally was issued by USEPA in 1999 as part of OSWER Directive 9200.4-17P. The approach worked well for characterization technology that was available at the time. Where do modern characterization techniques such as CSIA, qPCR, proteomics, high purity carbon 14 degradation assays and assays for reactive minerals fit into the lines of evidence approach? Although most of the new techniques do not fit neatly into an EPA line of evidence, they can be used in combination to provide the second and third line of evidence. The new techniques make the greatest contribution when they can be used to validate and confirm a rate constant for degradation that is extracted from the monitoring data. Having confidence in a rate constant for natural attenuation processes in an aquifer can support a decision to transition to MNA from an active remedy like pump-and-treat.