ABSTRACT

In much of the western United States mineral industry waste facilities are separated from the groundwater table by hundreds of feet of unsaturated sands, silts and clays. This is often considered an advantage due to the slow movement of fluid in the unsaturated zone, but by the time contamination is discovered in a groundwater monitoring well, the unsaturated materials beneath the site may have accumulated significant amounts of contamination. The costs for assessing contamination, remedial investigation, and/or cleanup of the large scale mining operations common to the western United States are becoming so great that, when added to mining costs, they often impact the economics of the overall mining operation. The purpose of this chapter is to report preliminary results of electromagnetic (EM) wave diffusion geotomography surveys recently conducted at the University of Arizona’s San Xavier Mining Laboratory.