Gas Hills Uranium Recovery Facility

DOWL provided geotechnical services for the proposed Gas Hills Uranium Recovery Facility located within a reclaimed surface uranium mine in the Gas Hills of Wyoming.

Historically, the site was mined from 1959 until 1983. During that period, the extent of the mine changed with interim backfill placement and additional mining activities occurring. Due to the nature of the proposed site, relatively unconsolidated fills exist with maximum thicknesses exceeding 100 feet. Proposed new construction for the Gas Hills Uranium Recovery Facility includes a heap leach cell, evaporation pond, process plant with adjacent process pond, administration building with parking area, warehouse, tank farm, ore receiving area to include ore stockpiles, hoppers, belt feeders, dump bays, and access/haul roads.

The project included drilling exploratory boreholes, percolation testing, surface seismic velocity surveying, laboratory testing, engineering analyses including settlement of the proposed heap leach cell, settlement/bearing capacity of building foundations, and slope stability of the heap leach cell. In order to estimate settlement of the heap leach cell situated over nearly 100 feet of previously placed, unconsolidated fill, the team used finite element software SIGMA/W.