Automated Impedance Tomography for Monitoring Permeable Reactive Barrier Health

76166-Although permeable reactive barriers are an important new treatment option for groundwater remediation, no reliable methods are available to monitor or predict their long-term behavior. The large-scale implementation of reactive barriers will require a means of monitoring their long-term degradation. For example, gaps can occur in the placement of the reactive material, particularly when construction methods such as jetting or deep soil mixing are used. This project will develop a reliable method to verify placement and monitor effectiveness of permeable reactive barriers. The approach will use arrays of inexpensive electrodes, coupled to autonomously operating hardware and software, to characterize the barrier and determine its effectiveness. Phase I will conduct column tests for monitoring the specific geochemical conditions and aging of the chosen sites. The requirements for data accuracy, sensor spacing, and borehole locations will be determined using numerical modeling. A fully autonomous system will be developed and a site will be chosen for a Phase II field implementation. Commercial Applications and Other Benefits as described by the awardee: The automated monitoring system should find use in more than 100 permeable reactive barriers that will have been installed in North America by the time this project is completed.