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4.0 PAD E%TENSION DESIGN <br />• <br />4.1 Pad construction <br />- The pads will be constructed as follows: <br />1. The topsoil will be removed from the area to be covered by the <br />-~ - extended pad, and stockpiled for future use. <br />2. The waste rock will be end-dumped in a single lift. This will <br />result in the largest sized material migrating to the base of <br />the pile, creating a higher permeability material at the toe, <br />to act as a drain in the unlikely event that the pad materials <br />were to approach saturation. This proposed approach is <br />considered to be allowable in this situation as the material <br />being placed is development rock, essentially free of <br />combustible material, and the disposal is above the water <br />table. In the event that this is proposed approach causesf~ <br />concern, NCEC are prepared to compact the fill in 24" lifts asll <br />per Section 4.10.4(3)(b). <br />-- - 3. Following placement in this manner, the material will be <br />-- periodically push-dozed to the required 2h:ly slope, by moving <br />- material from the crest downhill. <br />4. On completion of the tunnel excavation, the front face of the <br />~~'' pad will be smoothed, a 16 inch thick topsoil layer applied to <br />the face, and the face revegetated in accordance with the site <br />reclamation plan. This reclaimed surface will meet all <br />requirements for a permanently reclaimed slope, and will <br />resist ingress of water and oxygen, and prevent any <br />possibility of combustion. The 16 inch cover depth is <br />optimal: deep enough to provide an excellent growing medium, <br />and shallow enough to prevent erosion because of the rock <br />--- materials that are immediately beneath the cover. <br />5. On completion of the project, the upper pad surface will be <br />reclaimed, by filling to approximate original contours with <br />available waste rock materials, topsoiling, and revegetating. <br />The specific plan for each pad is discussed below. <br />4.2 #1 Portal oad <br />Portal #1 pad will be extended to the north, with the face slope <br />being flattened from the current 35° to the required 2h:ly (26,5°). <br />The plan of the extension is presented on Figure 2, together with <br />a cross section through the thickest portion of the pad. <br />The volume of material that would be required to achieve the <br />• Adrian Brown Consultants -7- 1145/900531 <br />