Engineered upland sulfide tailings management facility

This paper examines the various types of upland containment facilities investigated for the disposal of Crandon Project tailings. Based on the studies performed, a drained containment facility with a base composite liner, a leachate collection system and a dry cap with a composite hydraulic barrier was selected. Included in the paper is a discussion of the modeling completed for water movement through the final cover and within the tailings mass to predict percolation rates through the base liner. The extensive modeling showed that the base liner is critical in the control of percolation throughout the operation and tailings dewatering period, and that the final cover is critical in the control of oxygen transport and percolation from the facility in the long-term. The paper also discusses oxygen transport and geochemical modeling, and the solute transport modeling completed to assess compliance with applicable groundwater standards.