Electrical Resistivity Monitoring on an Experimental Landfill Clayey Cover

In France, a cover is set on the top of waste at the end of the exploitation of the landfill. The monitoring of landfill cover after closure of the site is a local problem, since its tightness must be ensured over time. Leaks in the cover allow water to infiltrate the stored waste. In order to define the ability of electrical resistivity tomography, an experimental clayey cover has been built in which defects have been intentionally made. Repeated measurements taken on this site showed that the detection of defects need to take into account the weather conditions preceding the measurements, as they affect the water content in the cover material. A statistical analysis carried out on the electrical resistivity values for all surveys at different dates has defined four clusters. Moreover, analysis performed on several cover material samples corresponding with the different clusters showed that the material was heterogeneous, because of a difference in particle size (fines content). This study has outlined, in addition to the detection of cracks, that electrical resistivity varies with the water content measured on site exponentially for each cluster.