Use Of Resistivity Monitoring Systems To Detect Leaks From Storage Ponds

A resistivity monitoring system was installed beneath and around a fifty-five acre<br>evaporation pond at the Mohave Generating Station in Laughlin, Nevada. The system was<br>installed to detect leakage of brine from the pond. The system consists of sixty-three<br>electrodes which are placed in a 7 by 9 grid using a go-meter spacing.<br>The feasibility of using this monitoring system was demonstrated by a scaled-down field test.<br>This field test determined that distinct measurable changes in resistivity occur in response<br>to the influx of water into the vadose zone. A direct correlation of increases in measured<br>voltages relative to the amount of water put into the ground was observed. Threedimensional<br>numerical modeling of the leak, using a finite-difference code, confirmed that<br>the changes observed in the field test were due to the influx of water.