2020-08-07_REVISION - M1980244 (5)

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Cripple Creek&Victor Gold Mine Valley Leach Facility 2 Phase 3 ■ Detailed Design for Permitting,Revision 1 NewFields Project No.475.0106.033 July 2020 to characterize the materials encountered during the field investigation and confirm field interpretation of the materials. Moisture content of the samples ranged between approximately four (4) percent and twenty- seven (27) percent. Particle size analyses were completed on select samples. The test divides individual soil samples into groups according to grain size and determines the relative proportions by mass of each individual grouping. The results are used to divide each specimen into percentages of gravel, sand, and fines. Fines are a grouped classification for both silt-and clay-sized particles described as smaller than the No.200 sieve size(0.075 mm). As previously noted,advancing the air hammer can cause pulverization or fracturing of the materials encountered and may affect the particle size distribution of the samples that were collected. Each sample was categorized according to the USCS which is based on the material gradation as determined by the laboratory results. Individual laboratory sheets and summarizing the soil classification,and natural moisture content tests are included in are included in Appendix C. Additional Liner Interface Shear Testing (LIT) was completed in May of 2019. The results of the LIT are presented in Appendix C and are discussed in Section 5.1.3. 4. VALLEY LEACH FACILITY DESIGN 4.1. General The VLF2 Phase 3 expansion design is consistent with the previously approved VLF2 designs that have been constructed. Characteristics of the Phase 3 expansion are summarized below: The Phase 3 expansion will expand the VLF2 footprint into the Schist Island Pit and east against the SGOSA, adding 8.1 million square feet of lined area and increasing the capacity of the facility by 118 million tons. > The majority of the VLF2 Phase 3 expansion footprint sits within previously disturbed land; i.e., the footprint already has been cleared and grubbed of unsuitable materials, topsoil has been removed and stockpiled, and the underground workings have been removed or already remediated. The expansion includes a second PSSA in the VLF2 facility. The Phase 3 PSSA is located within the Phase 1 Schist Island Pit and has an embankment located along its western edge. Y The expansion will include a composite liner system within the pad lined area and PSSA. The liner systems are identical to the liner systems previously deployed in VLF2. The Phase 3 expansion will be constructed in three stages. Page 6