Evaluation of Hydrocarbon Pollution Plume Extension Using Electrical Resistivity Method

Electrical properties of a light non aqueous liquid have been used for non-invasive tracking of a historical polluted area. Based on laboratory results which showed distinctive electrical properties for oil products (very high resistivity), VES and ERT investigations were designed in an area located near an industrial facility. Electrical profiles, placed along the groundwater flow direction, allowed to separate a highly polluted area extending over 300m far from the industrial facility perimeter. Despite the significant drop of the apparent electrical resistivity values after “Sector A” zone, the chemical analyses of water samples revealed a high content of volatile compounds and free fractions of petroleum hydrocarbons. After 1D simulations, it was assumed that in the rest of the area, the thickness of the polluted layer is much diminished, requesting more sensitive geophysical measurements for a better assessing of the soil pollution.