THE REUSABLE ELECTRODE WELL: A NEW TOOL FOR ENVIRONMENTAL MONITORING

Electrical resistivity tomography (ERT) provides useful hydrogeologic data but is difficult to integrate into current site characterization plans designed for monitoring well data. Methods have been developed to install ERT electrodes with direct push equipment; however, these do not allow for cable extraction and reinstallation in the same location. If a cable were damaged, an entirely new installation would be required. The use of a slotted PVC casing will allow a new cable to be added to the well without fear of formation collapse or inability to retrieve the cable. In this new method, a slotted PVC liner is installed and filled with a conductive material. An electrode array is then added using a nonconductive rod to push the cable into the borehole. The cable can then later be retrieved by simply pulling it out. This set up allows several arrays of wells to be installed and the use of fewer cables, which are swapped between the various boreholes. This will drastically reduce the cost of doing full site 3-D borehole surveys and allow greater versatility in the types of surveys conducted.