ABSTRACT
ABSTRACT: In September, 2007, Denison Mines (USA) Corp. received permits from the Utah Division of Oil, Gas, and Mining to begin mining operations at the Tony M Mine, an underground uranium mine that was originally developed by Plateau Resources in the 1980’s. Previous reclamation included breaching the dam that had been constructed to retain water pumped from the mine. Following geotechnical investigation by Tetra Tech during 2006, the dam and appurtenant facilities were re-designed, and construction occurred during 2007. The pond subgrade provided a cost effective, low permeability native barrier between the mine water and the underlying sediments. The liner consisted of reconditioned and densely compacted native clay overlying Brushy Basin Clay. Seepage through the pond liner and at the toe of the embankment was analyzed for steady-state and transient seepage conditions using a finite element computer model.
