Use of geophysical surveys during the planning, construction and remediation of landfills

Abstract

Abstract There are growing environmental pressures over the development, use and remediation of closed landfill sites throughout the UK, as well as overseas. There is also a reluctance to use direct investigative methods for fear of compromising the integrity of the landfill cap and liner systems. Consequently, there is an increasing role for geophysical surveys to be undertaken that are technically reliable, cost-effective and environmentally benign. Geophysical surveys have been proven to be successful in the assessment of site suitability during the planning stage. For example, evidence of former mining, adverse geological structure, soft zones and areas with anomalous permeability may be detected. Geophysics can be used for mapping the thickness of mineral liners during the construction phase. Closed landfill sites can be investigated geophysically without invasion of the structure to determine the location of margins and the depth of fill, map possible leachate ponding and migration, and to assess the integrity of mineral and artificial liners, etc. It is concluded that with current developments in data acquisition, processing, display and interpretation of geophysical data, the scope of environmental applications where multi-method geophysical surveys can be used is increasing rapidly. The range of geophysical methods currently available provides a powerful suite of investigative tools which complement direct observations.