Method for capping mine waste and tailing deposits

A method for providing a composite capping cover for maintaining the surface of a sulphide bearing tailing and mine waste containing deposit moist thereby substantially eliminating oxidation of the sulphidic particulate in the deposit and the formation of heavy metal salts. The moisture is provided by atmospheric precipitation. The composite capping cover comprises a fine particulate layer, a fine-granular particulate layer and a coarse-granular particulate layer, the particle sizes of the particles making up the individual the layers having been selected such that the hydraulic conductivity of the layers increases with successive layers while the matric suction value within the layers decreases.