Scholefield Tailings and McCleary Waste Alternative Geochemical Characterization

This Technical Memorandum was prepared by Tetra Tech and presents a geochemical characterization of the tailings and waste rock materials for the Scholefield Tailings and McCleary Waste Alternative being considered in the US Forest Service Environmental Impact Statement (EIS) for the proposed Rosemont Copper Project (Project).

In 2007, Tetra Tech published a Baseline Geochemical Characterization report and a Geochemical Characterization Addendum Report for the proposed Project as part of the Mine Plan of Operations (MPO). In addition to these two (2) reports, several technical memoranda have been prepared for the Project which provides supplemental geochemical information and testing. The Scholefield Tailings and McCleary Waste Alternative differs from the MPO primarily in the design and location of the Waste Rock Storage Area and the Dry Stack Tailings Facility. This alternative does not change the location of the proposed Open Pit or the source of waste rock and tailings materials.

Since the source of waste rock and tailings materials does not change in the Scholefield Tailings and McCleary Waste Alternative, the geochemical test results and conclusions published to date are still applicable to this alternative. The following sections of this Technical Memorandum provide a general summary of the overall geochemical characterization of the tailings and waste rock materials associated with the Project.