Numerical Study of Sediment and Chemical Transport in the Lower Athabasca River Due to a Tailings Dam Breach Spill and in the Context of Climate Change

Tailings dams are notorious for causing accidents and have been the cause of fatal accidents before. Now this question is raised, what consequences will befall us due to the possible failure of tailings dams, and will these effects still remain over time? These dams provide the possibility of storing wastes from the mineral extraction process on a large scale and for a long time. Only in the current century, which has passed nearly 2 decades, 11 serious breaks in these dams have been reported, and it seems that this number is increasing. At the same time, the probability of failure and collapse of tailings dams are higher than in water dams, and the reason for this is their industrial use. Water dams are reliable structures that are used to store water and be efficient in its use, while tailings dams are used to store residues that are not needed. As a result, we prefer to spend the least amount of money on their construction. To answer the question of why a tailings dam collapses, several reasons can be put forward, such as the weight that is imposed on the dam as a result of heavy rains and the weak foundation of the dam. Also, the transformation of solid waste into a liquid substance can lead to the discharge of waste to the water surface and underground water, which is a threat to wildlife. Many historic catastrophic tailings dams failures in Canada have raised concerns about the risk associated with oil-sands tailings, such as safety and environmental impacts. Therefore, it has increased the interest to investigate the potential effects of the failure of an oil sand tailings dam on the water quality as well as the adjacent lands in the downstream area. Studying and modeling the flow after the failure of tailings dams creates its own difficulties due to the non-Newtonian behavior of tailings materials. This study aims to numerically investigate the flow of dam breach tailings on oil sands tailings dams.