The regulations for backfilling of mining cavities and for landfilling contain concentration limits for the recovery of certain metals. The research project examined whether the applicable concentration limits could be reduced, whether further types of metal should be examined and limited, and whether the regulations should also be applied to the waste to be disposed of at landfills. The aim is to improve resource conservation by increasing the recovery of metals from waste, e.g. which would be irretrievably lost after the shift in mining cavities. Therefore the metal contents were investigated in quantity-relevant waste streams, their binding forms, suitable technical processing methods and the winning costs, in order to be able to evaluate in advance the effectiveness of possible limit value changes.