Mining facilities pose distinct challenges when characterizing hydrogeologic settings to assess potential impacts during project development and permitting, start-up, during operations (e.g., mine dewatering, slope stability support), and after closure when groundwater remediation may be required. Mining facilities are typically associated with complex hydrogeologic settings and extreme environments. Mining projects typically involve consideration of fracture flow, regional-scale aquifers with local-scale dependencies, open pits, underground workings, groundwater-surface water interactions, waste rock dumps, tailings facilities, and development of pit lakes. These challenges provide opportunities for creative problem solving and innovation. This session provides a forum to discuss best practices, innovations, and issues in characterizing the hydrogeology and managing environmental issues at mining facilities.