Geophysical Methods Applied to Characterize Landfill Covers with Geocomposite

We attempt to characterize with geophysical methods the state of landfill covers to detect damages that can induce preferential water pathways and unusual increase of leachate within the waste mass. The geophysical methods used were the Electrical Resistivity Tomography (ERT), cartography with an Automatic Resistivity Profiling (ARP©), and the Self Potential method (SP). We worked on experimental parcels reproducing common defaults on landfill covers (clay material and geocomposite) and on a larger scale on a french landfill cover. The joint use of these methods gives us the opportunity to test their ability to detect defects. Results on the parcels have shown a good detection of the larger cracks (0.10 m) on the compacted clay cover but a less easy detection of defaults on the geocomposite. Results on the landfill have shown conductive zones correlated with important SP variations that could indicate a preferential infiltration zone in the cover.