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Record of Construction Report,VLF2 Recertification Report,Subgrade and Geoembrane 9650'-9750'Elevations <br /> Response to DRMS Comments <br /> NewFields Job 475.0106.026 ■ <br /> July 16,2018 <br /> Once the limits of the geomembrane damage were defined in the field by exhuming the ore in <br /> the area of the slump, the contractor proceeded to carefully remove the remainder of the DCF <br /> and ore in the vicinity of the damaged geomembrane. The steps taken by the contractor to <br /> protect the SLF from the effects of weather and heavy equipment included; leaving the existing <br /> undamaged geomembrane intact during removal of the ore and DCF, and leaving the DCF/ore <br /> material cover in place covering the SLF within the limits of damaged geomembrane until <br /> immediately before deployment of new geomembrane liner. No heavy equipment was driven <br /> directly over the SLF without a minimum of two feet DCF over it during the removal process. It <br /> should be noted that the SLF was only exposed for a short period between the visual inspection <br /> of the SLF and the deployment of new geomembrane liner. <br /> Once the SLF was exposed completely there was evidence of slippage at the interface between <br /> the SLF and the geomembrane liner. This makes sense given the interface between the SLF and <br /> liner is the weak link in the stability of the pad. To further investigate damage to the liner system <br /> and particularly the SLF, we conducted a thorough visual inspection of the SLF and found no <br /> evidence of damage to the SLF layer itself. In fact, the SLF was in excellent condition with no <br /> evidence of damage such as tension cracking, desiccation or any sort of scarp/separation that <br /> would be indicative of damage to the layer. Depth measurements were also taken to confirm <br /> that the layer was still intact. All depth measurements taken yielded depths (12-inch minimum) <br /> that were consistent with the design requirements for the layer and observed depths during <br /> construction, in effect the layer geometry had not changed appreciably from the time that it was <br /> placed to the time is was exposed during this investigation. Given the SLF layer did not exhibit <br /> any form of distress it was deemed to be intact and undamaged and did not need to be repaired. <br /> The settlement overserved in the VLF Foundation of approximately 9-12 inches is within the <br /> design tolerances discussed in the Squaw Gulch Valley Leach Facility Design report. This <br /> settlement is considered minor and did not damage the liner system. <br /> It is our opinion that density testing was not required given there was no evidence of damage to <br /> the SLF layer observed in the field. Had damage been observed, rework and repair of the SLF <br /> layer would have been warranted and density testing would have been prudent. Given the SLF <br /> showed no signs of damage, the surface of the layer was moisture conditioned and proof rolled <br /> to verify that there was a firm unyielding surface prior to new liner deployment. <br /> Based on our visual inspection of the exposed SLF surface, our professional experience and <br /> industry standard practices on similar geomembrane liner repair projects, no additional testing <br /> on the SLF was warranted and the surface was re-approved to allow the placement of <br /> geomembrane. Based on the forensic investigation and reconstruction of the liner system <br /> completed,the engineer hereby certifies that the SLF is in fact intact and will perform as designed <br /> as a functional component of the composite liner system. <br /> Page 2 <br />