You are here:
Emerging Trends in Regulatory Implementation of MNA
Citation:
WILSON, J. T. Emerging Trends in Regulatory Implementation of MNA. Presented at University Consortium for Field-Focused Groundwater Contamination Research 2008 Focus Meeting. Natural Attenuation Tools for Quantification and Implications, Denver, CO, October 23 - 24, 2008.
Impact/Purpose:
John Wilson has identified the following trends, and potential changes in regulatory implementation based on his experience providing technical assistance at CERCLA sites
Description:
There are two EPA documents relevant to MNA of Chlorinated Solvents: the Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water. EPA/600/R-98/128 September, 1998, and Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites Directive 9200.4-17p, April, 1999. The ORD Protocol defined a specific technical approach to evaluate MNA at particular sites, while The OSWER Directive delineated EPA’s expectations for performance of MNA. The two together allowed expeditious application of MNA to the sites where it is appropriate. Starting in 1999, the two together reversed a tendency to select MNA as a default remedy. However, current trends in selecting MNA as a remedy is rebounding in recent years compared to a leveling off after issuance of the MNA Directive. This has raised some concerns among regulatory staff in U.S. EPA. John Wilson has identified the following trends, and potential changes in regulatory implementation based on his experience providing technical assistance at CERCLA sites. MNA at Superfund sites will come closer to the Superfund definition of MNA; MNA will be expected to meet a clean up goal in a “reasonable” amount of time. The five year review process will become more focused, and less open-ended. After review of the long term monitoring data, interim cleanup goals might be negotiated to guide decisions in the next five year review. Contingency remedies would be triggered by failure to meet the interim cleanup goals.