Electrical flow paths and the application of the resistivity method to the evaluation of landfill’s lining systems

Abstract

Results from two ERT performed on an empty small-scale pilot plant are presented illustrating the electrical current pathways in the presence of a conductive layer electrically insulated and partially insulated from the surrounding environment by a geomembrane. An ERT acquired on an operating cell of a real landfill where electrical connection is present between the inner medium (leachate, waste and covering soil) and the outside environment is also presented. Both results draw attention to the need of considering the slope of cell walls when interpreting ERT models from a survey performed on an operating landfill, since it is possible that the conductive bottom layers couldn’t be related with a hole or other sort of defect on the geomembrane, which could facilitate the environment contamination, but with the deviated electrical pathways through waste and leachate. In this case a good topographical mapping before and after the cell’s exploration is a key factor