Co-authored by Matt’s RSK geophysics colleagues Tim Grossey and George Tuckwell, the article begins by introducing geophysical surveys as “often the only practical method of investigation on landfills as they do not involve penetration of the cap or liner and exposure of any wastes”.
Matt then moves on to present a recent RSK case study, a near-surface geophysical survey from a closed landfill in Denton, near Manchester, UK. The project provides a good example of using geophysical surveys as best practice: “Given the sensitive nature of the residential environment, the use of rapid, non-intrusive surveying techniques was preferable.”
He concludes, “Closed landfill sites in particular pose a potential risk to groundwater resources. Although there is no single instrument or technique that is right for every situation, in the case of landfill sites where significant electrically conductive material is present, these can provide a suitable environment for the deployment of electrical resistivity, EM [electromagnetic], and GPR [ground-penetrating radar] to successfully delineate the structure of the landfill and clearly map out areas of anomalous conductivities in a safe, rapid, and cost-effective manner.”
Conductivity data: red and pinks are high conductivity values (>50 mS/m), with green colours representing lower background conductivity.