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NewFields <br /> Perspective. Vision. Solutions. <br /> July 16, 2018 <br /> NewFields Job 475.0106.026 <br /> Cripple Creek &Victor Gold Mining <br /> P.O. Pox 191 <br /> 100 North 3rd Street <br /> Victor, Colorado 80860 <br /> Attention: Mr. Laurin Colby <br /> Senior Metallurgist <br /> RE: Cripple Creek&Victor, Co., Cresson Project M-1980-244; <br /> Review of Record of Construction Report, VLF2 Recertification Report, Subgrade and <br /> Geomembrane 9650-9750' Elevations <br /> Dear Mr. Colby, <br /> NewFields Mining Design & Technical Services (NewFields) has prepared this letter in response <br /> to comments pertaining to the "Record of Construction Report, VLF2 Recertification Project, <br /> Subgrade and Geomembrane 9650—9750' Elevations" by the Colorado Division of Reclamation <br /> Mining and Safety (DRMS), received on July 13, 2018. DRMS comments appear in blue and are <br /> followed by NewFields' response. <br /> 1. Sect 3.4.1, SLF Testing: The text states "laboratory and density testing were not performed". <br /> The fact is not done provides an incomplete demonstration the liner system as repaired will <br /> function as originally designed. The SLF is not simply subgrode for the geomembrane, but on <br /> integral part of the dual liner system intended to provide secondary containment for potential <br /> leakage through the geomembrane of metallurgical processing fluids by acting as a clay liner <br /> with permeability requirements. The Division acknowledges the SLF material had been <br /> confirmed during the original construction to meet the technical specifications for gradation <br /> and plasticity because no mew material was introduced. However, due to the known failure <br /> of the geomembrane, observed settling (which was not discussed in this report), a <br /> demonstration needs to be made that the SLF still meets the original specifications. Because <br /> the SLF material itself is the some as what was originally placed and approved by the Division, <br /> a verification of the minimum thickness and compaction density would suffice for this type of <br /> demonstration. The Division will not accept the repairs to the liner system between 9650 and <br /> 9750 elevations until it is demonstrated the original design specifications have been met or <br /> exceeded during the repair effort. <br />