A review on the use of geoelectrical methods for characterization and monitoring of contaminant plumes

Geophysical characterization of contaminated sites is an important procedure in pre- and post-site remediation. It has been carried out in several contaminated sites, irrespective of differences in site geology, nature of contaminants, and prevailing hydrological conditions. Electrical prospecting methods are the most used geophysical techniques for contaminant plume mapping. Due to this widespread use, there is an increasing number of literature on the use of electrical methods directed toward contaminant plume mapping. Yet, it lacks a comprehensive framework in literature that synthesizes the methods’ concepts, applications, and limitations. In this review, we summarized the use of electrical methods (electrical resistivity, self-potential, and induced polarization) in mapping contaminant plumes and provided a synthesis of concepts, applications, and limitations. The advantages, drawbacks, and the solutions achieved so far were emphasized in this review. Some of the advantages are that electrical methods are faster, cheaper, noninvasive and provide continuous images of contaminant plumes when compared to the traditional techniques. The drawbacks highlighted include the non-uniqueness of the vertical electrical sounding (VES), distortion effect of the 2D electrical resistivity tomography (ERT) and huge cost of 3D ERT data acquisition. We also highlighted other geophysical methods that could be used to map contaminant plumes. Conclusively, this review paper identified future research direction and offers insight into emerging issues associated with these techniques for better modeling of contaminated sites.