Abstract: A system for preventing upward migration of contaminants in soil having capillary pores defined therein, the system comprising the soil and a hydrophobic substance applied to the soil, the substance being attracted to enter the capillary pores so that a barrier is formed which, under unsaturated soil conditions, prevents the upward migration of contaminants carried by water through the capillary pores in the soil.

Abstract: A process for removing water-soluble contaminates from soil includes laying a mat over and in contact with the contaminated soil, applying water to the soil, permitting the water to be transferred from the soil to the mat, permitting the contaminants to be carried via the water into the mat, and permitting the water to be evaporated from the mat so that the contaminants precipitate in the mat.

Abstract: Mine tailings and similar materials are disposed of by replacing the tailings in underground mineworks including the shafts, adits and drifts by forming a slurry of tailings using dredging or similar mixing processes and pumping the slurry to the mineworks. Cementitious materials may be added to selected quantities of the tailings slurries to form cement plugs for placement at selected intervals in the mineworks to minimize connectivity of the mineworks shafting, adits and drifts. The mineworks may be dewatered to provide a source of water for the slurrification process and the water may be reused after separation from the slurry. The disposal process provides a convenient way of replacing mine tailings in a repository of similar mineralogy and at least partially eradicates abandoned mineworks, including shafting, adits and drifts, which otherwise might require continual monitoring and dewatering.