Hydrogeological Analysis of Sulfide Tailings at a Uranium Mine Using Geophysical and Hydrochemical Methods

A hydrogeological analysis was conducted of aquifer systems within a sulfide-rich tailings pile and underlying rocks at a uranium mine to understand the generation and transport of AMD. A geophysical investigation was carried out along seven transects spaced 30 m apart using electrical resistivity tomography and a Wenner-Schlumberger array. The results were used as input to 2D and pseudo-3D models of resistivity and chargeability parameters. The geophysical results and models contrasted unaffected saturated zones and zones impacted by AMD, in addition to three areas within the tailings with a high sulfide content. The tailings and underlying fractured bedrock aquifer are hydrologically connected, which promotes the exchange of mine-influenced water into the regional aquifer. Releases from the site’s tailings and other wastes can severely affect regional groundwater.