2014-02-07_REPORT - M1980244 (7)

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Cripple Creek & Victor Gold Mining Company Mill Site Earthworks Project Final Report Quality Assurance Monitoring & Test Results January 31, 2014 ameO geotextile overlap was adequate, and a minimum of 6 inches of SSF placed on the top of the geotextile. 4.2.3 Overburden /Structural Fill (OVF) AMEC monitored the excavation and placement of OVF materials required to achieve the design grading for the project components. During placement field nuclear density testing was performed to ensure proper compaction was achieved. OVF material containing more than 30 percent by weight larger than 3/4 -inch particle size was placed by method specification (per Specification 02200.0 Section 3.06). AMEC verified that the OVF maximum particle size for fill did not exceed 24 inches, and lifts were no thicker than 1 -'/2 times the maximum particle size. There were four record tests containing materials larger than 24 inches; these tests were accepted by the Project Manager due to the small amounts. However, when the out of specification material was discovered, Ames was notified and the screening process evaluated and the materials were brought back within Project Specifications. When OVF was placed for slope reduction, AMEC verified that Ames scarified in situ materials prior to fill placement and that Ames made a minimum of four passes with the smooth drum vibratory compactor. 4.2.4 Soil Liner Fill Construction of the soil liner fill consisted of hauling, placing, and compaction of Soil Liner Fill material where it was to be covered with geomembrane materials and any other required locations. Field Monitoring AMEC observed SLF placement to verify lift thickness, adequate compaction, acceptable moisture content, final compacted thickness, and suitability for geomembrane deployment. Angular particles, ruts, and /or desiccation cracks on the finished surface were brought to the attention of Ames for repair. Ames addressed all deficient areas by placing additional SLF material and re- compacting the final surface prior to geomembrane placement. A final visual inspection of the prepared SLF surface was conducted by AMEC and Lone Star. Both parties approved the final SLF surface prior to geomembrane deployment. Moisture Density Test Results AMEC performed a total of 120 in -place moisture density tests of SLF. The field nuclear gauge moisture density tests were required to meet a minimum 95 percent compaction of the maximum dry density and optimum moisture content calculated during laboratory testing of the SLF material. The Standard Proctor maximum dry density and optimum moisture content values for samples containing more than ten percent + 3/4 -inch material were corrected according to ASTM D4718 to facilitate direct 18