Geophysical Data Processing Techniques As Related To Groundwater Contamination Studies

Shallow geophysical surveys are regularly applied to site investigations at some of the hundreds<br>of oil and gas facilities located in western Canada. Terrain conductivity surveys are frequently<br>used to map produced saline water plumes, abandoned flare pits, drilling sumps, and sulphate<br>plumes. Magnetometer surveys are regularly used to delineate landfills and identify pipeline<br>locations. Often, raw data accompanied by minimal data enhancement are sufficient to provide<br>the required information. On other occasions, however, simple but powerful data processing<br>techniques are necessary to give meaningful sense to the acquired data. In this paper, four case<br>studies are presented which illustrate the application of simple data processing routines to<br>overcome:<br>1. The influence of steeply sloping topography on terrain conductivity data,<br>2. The effects of very high soil salinities which may mask inorganic groundwater<br>contaminant mapping,<br>3. Difficulties in identifying relatively subtle, but discrete fractures in Tertiary<br>siltstone/sandstone bedrock, and<br>4. The challenge of electrically mapping complex structure at the subcrop level of the<br>bedrock/water table interface.