2019-12-13_REVISION - M1980244 (55)

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Newmont Goldcorp M■ VLF/OSA Closure Stormwater Analysis NewFields Project No.475.0106.035 November 8,2019 contractor shall vary the closure grades in order to generate more irregular landforms. The proposed grading plan can be seen on Figure 3. 2.3. Squaw Gulch Overburden Storage Area The closure surface presented was developed by CC&V and has a maximum design elevation at closure is 10,600 feet. During the reclamation regrading activities, the contractor shall vary the closure grades in order to generate more irregular landforms. The proposed grading plan can be seen on Figure 4. 2.4. Valley Leach Facility 2 Since the final design surface for VLF2 will be graded at a 2.51-1:1V overall slope, relatively little regrading will need to be done at closure. The area northeast of ADR1 that currently has steep grades at 1.4H:1V will have to be pushed out so that the overall slope is acceptable for closure (2.5H:1V minimum). The maximum design elevation of the proposed VLF2 closure facility is 10,650 feet and the proposed toe on the south side stays about 150 feet away from Highway 67. During the reclamation regrading activities, the contractor shall vary the closure grades in order to generate more irregular landforms. The proposed grading plan can be seen on Figure 5. 2.5. Valley Leach Facility 1 The VLF1 closure surface presented was developed by CC&V and the maximum closure design elevation is 10,400 ft. The western toe of the existing facility is approximately 50 feet away from Highway 67 and will be maintained during reclamation. The existing crusher pocket on the north east side of the facility will be covered by the closure surface. During the reclamation regrading activities, the contractor shall vary the closure grades in order to generate more irregular landforms. The proposed grading plan can be seen on the Figure 6. 2.6. Schist Island Backfill The Schist Island Backfill closure design surface was developed using the VLF2 final stacking and pad design by NewFields as well as the initial backfill design by CC&V. The west half of the fill will be graded to a 2.51-1:1V slope for a length of approximately 500 feet. The toe of slope will be approximately 200 feet from the Ironclad Access Road. The east half of the fill will be graded to a 5% slope, be sloped toward the west, and will tie into the final grading of the Globe Hill pit at an elevation of 10,200. During the reclamation regrading activities, the contractor shall vary the closure grades in order to generate more irregular landforms. The proposed grading plan can be seen on Figure 7. Page 2