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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 /> August 21,2019 <br /> 2.2.6. Remediation of Shallow Workings <br /> Workings that were less than 25 feet below the final SLF subgrade surface were excavated <br /> to bedrock and backfilled in 3-foot lifts with Select Structural Fill (SSF) or SF material. The <br /> SSF and SF material was compacted in accordance with the approved method of <br /> compaction specification discussed in Appendix E. In some instances, the shallow <br /> workings were removed in cut during slope contouring; thus, no further remediation was <br /> 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 (Pre-2019) No. 3 and Record Drawing (Post 2019) No. 4. <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/ydz 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 that <br /> all secondary underdrains were installed in accordance with the project Technical 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 thick <br /> loose lifts, moisture conditioned as required, and compacted using either a 10-ton vibratory <br /> smooth drum compactor or 19-ton vibratory sheepsfoot drum compactor. The entire surface of <br /> each lift was compacted with a minimum of four passes in accordance with the developed <br /> method specifications. The development of the method specifications is described in Appendix <br /> E. All subgrade preparation and SF placement associated with site grading was monitored by the <br /> 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 /> slope existed, two smooth drum compactors mounted in tandem with a dozer were used to <br /> P:\Projects\0106.032 VLF2 Phase 2 CQA\J-REPORTS\Cert Report-Phase 2A Part 1\DRMS Comments\475.0106.032 CCV PHASE 2A Part 1 <br /> ROC REPORT_Revl.docx <br /> Page 5 <br />