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Cripple Creek&Victor Gold Mine <br /> Valley Leach Facility Expansions ■ <br /> Detailed Design for Permitting <br /> NewFields Project No.475.0106.064 <br /> March 2024 <br /> Table 2.1-: Seismic Design Criteria <br /> Return Period PGA(g) <br /> 2,475-Year 0.13 <br /> 2.5. Subsurface Conditions <br /> Generally, the site of the VLF Expansion is in an area of relatively shallow bedrock with a thin <br /> veneer of colluvial soils. Existing topsoil and ore stockpiles are the only areas within the footprint <br /> that have a relatively thick package of soils over bedrock.Generally,colluvial soils consist of sands <br /> and gravels formed by slope wash of weathered in place bedrock. The geotechnical <br /> characterization program that was used to refine the geologic model provided by CC&V for <br /> subsurface conditions is described in Section 3. <br /> 3. GEOTECHNICAL CHARACTERIZATION <br /> Geotechnical investigations were completed during the design and development of the VLF <br /> Expansions, as shown on Drawing A007. A summary of the investigations is described in the <br /> following sections. <br /> i <br /> 3.1. VLF2 Phase 3 Expansion Site Investigation (NewFields, 2020) <br /> Six boreholes in the proposed footprint of the VLF2 Phase 3 Expansion were completed. The <br /> boreholes were drilled using a CME 550X ATV mounted drill equipped with 5.5-inch (outer <br /> diameter) ODEX down-hole air hammer. <br /> Based on conditions encountered in the boreholes, the general subsurface profile consists of 26 <br /> to 62 feet of gravel and sands over phonolite bedrock. Bedrock was encountered in borings BH- <br /> 03 and BH-05 at 45 and 30 feet, respectively. Groundwater was encountered in boring BH-05 at <br /> a depth of 35 feet. <br /> 3.2. Valley Leach Facility Expansion Test Pit Program (Newmont, 2023) <br /> Test pits were excavated within the VLF Expansion footprint to characterize near surface soil <br /> conditions. Excavations were completed with a John Deere 210G hydraulic excavator operated <br /> by Conley Construction to depths between 2.5 and 13 feet below ground surface (bgs). The <br /> excavation depth was limited by the machine reach and refusal on boulders and bedrock. <br /> Descriptions of materials encountered, and excavation depths were recorded in the field. Large, <br /> disturbed samples of soil and rock were obtained for laboratory testing. After completion, test <br /> pits were backfilled with excavated materials and recompacted to the original ground surface <br /> • elevation. Test pit logs are presented in Appendix A. <br /> Page 5 <br />