Using geophysical methods for detecting seawater intrusion and waste plumes in the river Foix delta (Catalonia, Spain)

Geophysical surveys, particularly electric and electromagnetic methods, have demonstrated to be useful for mapping inorganic conductive plumes and delimitating seawater intrusion into coastal aquifers (Frohlich et al., 1994). In the study area groundwater is affected both by salt-water intrusion and toxic industrial wastes. Therefore, the purpose of this study was to test a cost-effective geophysical methodology to detect saltwater in the shallow subsurface using electromagnetic ground conductivity and electrical imaging measurements to determine the immediate sources of leachate plumes flowing in the area.