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Cripple Creek&Victor Gold Mining Company <br /> Squaw Gulch VLF Phase 2A Part 1 ■ <br /> Record of Construction Report <br /> 475.0106.032 <br /> July 22,2019 <br /> 2.2.6. Remediation of Shallow Workings <br /> Workings that were less than 25 feet below the final SLF subgrade surface were <br /> excavated to bedrock and backfilled in 3 foot lifts with Select Structural Fill (SSF) or SF <br /> material. The SSF and SF material was compacted in accordance with the approved <br /> method of compaction specification discussed in Appendix E. In some instances, the <br /> shallow workings were removed in cut during slope contouring; thus, no further <br /> remediation was required. <br /> 2.3. Secondary Underdrains <br /> Squaw Gulch VLF Phase 2 was designed with an underdrain system consisting of secondary <br /> underdrains that tie into the Phase 1 underdrain system. The as-built layout of the underdrain <br /> system is shown on Record Drawing No. 2. <br /> Approximately 4,165 linear feet of secondary underdrain was constructed within the limits of <br /> Squaw Gulch VLF Phase 2. The secondary underdrain trench was excavated to the minimum <br /> dimensions shown on IFC Drawing A64. Geotextile and Underdrain Fill (UF) were then placed in <br /> the trench, and a minimum of 6 inches of SSF was placed over the geotextile. Approximately <br /> 58,310 square feet of 12oz/yd2 non-woven geotextile, 1,234 cubic yards (cy) of OF and 309 cy of <br /> SSF were installed when constructing the secondary underdrains. The CQA Monitor verified <br /> that all secondary underdrains were installed in accordance with the project Technical <br /> Specifications. <br /> 2.4. Site Grading <br /> Approximately 1,476,127 cy of SF material was used to grade the site within the limits of Squaw <br /> Gulch VLF Phase 2. Prior to SF placement, the existing subgrade was scarified to a depth of 6 <br /> inches, moisture conditioned, and compacted, as required. The SF was then placed in 2-foot <br /> thick loose lifts, moisture conditioned as required, and compacted using either a 10-ton <br /> vibratory smooth drum compactor or 19-ton vibratory sheepsfoot drum compactor. The entire <br /> surface of each lift was compacted with a minimum of four passes in accordance with the <br /> developed method specifications. The development of the method specifications are described <br /> in Appendix E. All subgrade preparation and SF placement associated with site grading was <br /> monitored by the CQA Monitor to ensure that it met the project Technical Specifications. <br /> 2.5. Subgrade Preparation <br /> The subgrade was prepared and inspected prior to soil liner fill (SLF) placement. The exposed <br /> subgrade surface was moisture conditioned and compacted using either a 10-ton smooth drum <br /> vibratory compactor or 19-ton sheepsfoot drum vibratory compactor. In areas where a steep <br /> P.\Projects\0106.032 VLF2 Phase 2 CQA\J-REPORTS\ROC Report 1\Cert Report-Phase 2A Part 1\475 0106.032 CCV PHASE 2A Part 1 <br /> ROC REPORT docx <br /> Page 5 <br />