Seepage and transport modelling for a uranium tailings dam in northern Saskatchewan

Disposal facilities for uranium tailings are commonly designed as surface or shallow subsurface facilities. To design such facilities, an understanding of contaminant transport processes under both saturated and unsaturated flow conditions is required. In this paper, a saturated-unsaturated finite element model to simulate the movement and distribution of contaminants in groundwater flow systems is presented. The finite element solution of the governing equations is based on the Galerkin weighted-residual method. The nonlinearity of the seepage equation in the unsaturated zone is solved by iterative techniques. The physical properties of several materials relevant to saturated-unsaturated flow modelling are presented. The modelling results of a representative section through the tailings dam of the Cluff Lake Mine tailings impoundment are presented as an example of how modelling techniques may be applied to design