2018-09-11_REPORT - M1980244 (4)

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Newmont Mining Corporation Record of Construction Report ■ VLF2 Recertification Project Subgrade and Geomembrane 9750'—9900'Elevations NewFields Project No.475.0106.026 August 17,2018 3.3. Damaged Geomembrane Removal After the geomembrane was exposed and the damaged area was identified, it was removed using a CAT track mounted excavator. The removed geomembrane was discarded into roll off trash receptacles and removed from site. 3.4. Existing SLF Preparation Prior to geomembrane installation, the existing SLF depth was verified and the subgrade surface to receive geomembrane was compacted using a track mounted excavator with a smooth drum compactor attachment. The SLF was inspected and approved by Comanco, Ames and NewFields prior to geomembrane deployment. 3.4.1. SLF Testing Due to the existing SLF layer being intact and undisturbed, laboratory and density testing were not performed since the geomembrane liner was not damaged and it was tested and approved during Squaw Gulch Phase 1 VLF construction.The surface was proof rolled to ensure the surface met the requirements the Technical Specifications for geomembrane deployment. 3.4.1.1. SLF Depth Checks Depth checks were performed in accordance with the Technical Specifications to ensure that the SLF was not displaced in the VLF2 Recertification area between the 9750' and 9900' elevations. The depth check frequency for SLF is two tests for every acre. Two SLF depth checks were required. Four SLF depth checks were performed within the VLF2 Recertification area between the 9750' and 9900' elevations with passing results. SLF depth checks locations and results are shown on Drawing 1. 3.5. Geomembrane Installation Comanco installed approximately 71,851 square feet of 80 mil LLDPE DSMS geomembrane within the VLF2 Recertification between the 9750' and 9900' elevations. The recertification area certified in this report is shown on Drawing 2. Fork lifts were used to transport and deploy the geomembrane panels parallel to the slopes to minimize stress on seams. Double-wedge fusion welding was the primary method of geomembrane seaming. Extrusion welding methods were used to perform tie-in seaming, defect repairs and detail activities. Continuity conformance of fusion welded seams was performed using pressure testing methods, while extrusion welded seams and repairs were non-destructively tested using vacuum testing methods. Destructive testing was performed for both seaming types. The CQA Monitor observed and documented all Page 6