Håkan Rosqvist

Potential of Geoelectrical Imaging Techniques for Detecting Subsurface Gas Migration in Landfills - An Experiment

We measured eleven regularly spaced resistivity profiles over a ten by ten meter experimental plot where high landfill gas (LFG) emissions had been recorded on the surface. The measurements were repeated seven times during four days which made it possible to trace the development of resistive areas. The LFG emissions at the surface of the landfill were estimated with laser absorption spectroscopy and static chamber measurements at the same time as resistivity surveying. By studying the changes of resistivity with time it was indicated that the gas migration in the waste mass was a relatively fast process, changing within only a few hours. Our presentation will focus on details regarding temporal and spatial changes of measurement.

An Evaluation of the Potential of the Geoelectrical Resistivity Method for Mapping Gas Migration in Landfills

Methane is a powerful greenhouse gas and growing concern regarding global climate changes over the last years has pointed out the need to quantify and control the leaking of methane into the atmosphere. Landfill gas is regarded as one of the major sources for methane migration to the atmosphere. In this study we present research work with the objective to evaluate the use of geoelectrical resistivity to detect gas migration in landfills. Extensive field experiments were conducted at the Filborna landfill site in Helsingborg, Sweden, in August 2008. In general, the resistivity measurements showed results corresponding to results reported from previous investigations in waste. However, also large variations in resistivity were indicated. Relatively high variability and high mean resistivity in the surface-near layers clearly indicate influence on the resistivity in the upper zone of the landfill. The variability and high resistivity may partly be explained by appearance and migration of landfill gas.