On November 25, 2013, EPA issued a new groundwater cleanup guidance document specifying the need for a well-by-well review when determining whether groundwater restoration remedial action is complete.
EPA’s document, Guidance for Evaluating Completion of Groundwater Restoration Remedial Actions, states that “data from each monitoring well should be analyzed independently to determine that cleanup levels for all COCs have been met and that the groundwater will continue to meet cleanup levels for all COCs in the future, in accordance with the CERCLA decision document.”
Further, according to EPA, “To provide a complete restoration evaluation of the lateral and vertical extent of the contaminated aquifer, we do not recommend the use of data analysis tools to compare or aggregate conclusions between wells. For the same reason, if the well is constructed to sample from multiple discrete depths (i.e., intervals), we do not recommend the use of data analysis tools to compare or aggregate conclusions between intervals.”
EPA’s most recent document is just one of several groundwater guidance documents recently announced by the agency. On October 29, 2013, the agency also issued a draft Groundwater Remedy Completion Strategy document. EPA is seeking public comment on the draft until December 20, 2013.