During active uranium mining, stockpiling of waste rock and overburden created 48 waste piles at the numerous sites of Wismut. These waste rock piles could not be left in their original state. Depending on their location, shape, and contaminant inventory, they presented various hazards to humans and the environment. Wismut GmbH therefore has the task of safely and permanently rehabilitating all its waste rock piles. In the remediation of waste rock piles, two different approaches are followed. Some of the waste rock piles are excavated and moved either to engineered sites or to the mined-out Lichtenberg open pit. In cases where relocation is not feasible on technical grounds, Wismut opts for in situ, i.e. in-place remediation. Whatever option is chosen, immense quantities of material have to be moved.