Mapping of Landfills Using Time-domain Spectral Induced Polarization Data - The Eskelund Case Study

This study uses time domain IP for the delineation and the characterization of the former Eskelund landfill, Denmark. With optimized acquisition parameters combined with a new inversion algorithm it is now possible to use the full content of the decay curve and retrieve spectral information from the time domain IP data. Thirteen IP/DC profiles were collected, supplemented by en el-log drilling for an accurate correlation between the geophysics and the lithology. The data were inverted using a laterally constrained 1D inversion considering the full decay curves to retrieve the four Cole-Cole parameters. For all profiles, the results reveal a highly chargeable unit with an impressive agreement to 15 boreholes. The thickness and the depths have been validated by el-log measurements giving in-situ values for the Cole-Cole parameters. The 3-D shape of the waste body has been delineated with a very high accuracy, and the south boundary of the landfill has been redefined based on these results. The inversion of the IP data also allows reconstruction of the waste history combining aerial maps with the results. Thus, this case study shows the relevance and the full benefits of using the TDIP data for the recognition and the characterization of landfill areas.