Reactive subsurface barriers for groundwater remediation require systems to ensure that the barrier is continuous along its length (without any breaks or holes) and that it continues to remediate the groundwater passing through the barrier.  Electrical resistivity measurements made within the barrier wall offer the potential to reliably address these needs in a low-cost manner.  This project will evaluate the use of discrete electrodes, located within the reactive media itself, to create two-dimensional images for ascertaining that the barrier is free of any holes that would permit contaminated groundwater to pass through.  The same electrode configuration also will be used to monitor the capacity of the reactive barrier to continue treating the groundwater.  Phase I will use numerical modeling to determine the optimal electrode configuration within the wall.  The optimal electrode configuration will be evaluated in a small-scale physical model to confirm its ability to detect holes in the barrier.  Physical models also will be used to evaluate changes in the electrical properties of the reactive media over time (as it becomes depleted, clogged or washed out) in order to assess whether it is no longer effective at remediating the groundwater plume.

Commercial Applications and Other Benefits as described by the awardee:    The technology should provide a way of determining the continuity of an in-situ barrier without excavating the barrier for visual inspection, or waiting for downstream monitoring wells to indicate contamination (i.e., when it is already too late).  The approach should be applicable to all subsurface barrier systems used for groundwater remediation.