Abstract

There is increasing interest in the hydrologically closed basins of western Utah and Nevada for disposal of low- and high-level waste. For much of this region there is insufficient field data to characterize subsurface flow paths for waste disposal design and analysis. In this paper, results from numerical experiments are presented indicating how mountain recharge and playa evaporation might affect the circulation of ground water in closed basins. In particular, the simulations demonstrate the effects of vertical and horizontal fluid-density gradients on flow beneath saline lakes and playas. These density gradients are the result of high evaporation rates on the playa. The simulations show that free convection of the dense brine results in a salt nose which forms under the margin of the playa-lake. The implications of this circulation for waste disposal and the transport of dissolved trace contaminants are discussed.