A Simplified Leak Current Model for Electrical Landfill Leakage Detection

The electrical leakage detection methods are widely used to locate leaks in the geomembrane liners at landfills. The potential distribution in the medium above the liner determines the leak locations. A reasonable leak current model is the theoretical basis of potential distribution analysis. The traditional leak current model advanced by Parra results in a complex expression of potential, which is relative to many parameters. The complexity of equation lead to difficulty in the theoretical study. We set up a simply leak current model based on the fact the geomembrane liner is electrically resistive. The leak current was regarded as a point current source in this new model. The potential expression based on the new model was deduced. The comparisons between the two models show that: 1) the influence of the liner thickness and soil resistivity below the liner on the potential distribution in the medium above the liner is tiny, which can be totally ignored; 2) the calculated results according to the two models, respectively, are fully consistent on condition that the leak current is 100 mA and the medium resistivity above the liner is 30 Ω.m.