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serves two purposes. First, the volume of material left in the highwall will allow the crest to be <br /> pushed towards the toe with the final mining slope of 2H:IV, which will maximize gravel <br /> recovery and additionally will reduce the required backfill material to bring the slopes to a <br /> 3H:1 V slope. Secondly, this offset provides additional slope safety. A failure would be <br /> governed by the internal angle of friction of the material. This would limit the failed slope to an <br /> angle of 34 degrees or—1.3H:1 V. This failure would not only stay within the permit area, it <br /> would stay within the final slope envelope. Such a failure is unlikely given that only the active <br /> slope is near vertical. <br /> The expected annual average production is 200,000 tons. Actual production rates will fluctuate <br /> based on market conditions. The raw material will be sold as various products: crushed rock, <br /> chips, road base, concrete, and asphalt. A breakdown of the anticipated product tonnages and <br /> mined tonnages can be seen in Table D-1. A breakdown of the estimated areas is included in <br /> Table D-2. Both topsoil and overburden may be sold onsite on an as needed basis, however <br /> Rock Pile commits to keeping enough material onsite to be able to reclaim the site. The amounts <br /> of topsoil and overburden sold are secondary commodities and are not therefore included in the <br /> table below or the annual tonnage sold from the site. <br /> Mine access will be via 6175 Road, as it has been to this point. <br /> No pit dewatering will take place, as the groundwater table is well below the bottom of the pit <br /> elevation shown on Map C-2. No groundwater will be exposed, and if it is encountered, pits will <br /> be backfilled to two feet above groundwater. <br /> Mining will progress through the areas in numerical order. The topsoil and overburden from a <br /> new area will be used to reclaim the previous area. This will reduce material moving as well as <br /> reduce the maximum area to be reclaimed. A table of expected mining lives for each area is <br /> included in Table D-1. The life of each pit is based on the anticipated annual average tonnage. <br /> No explosives will be used in conjunction with the mining and reclamation operation. <br /> Base Products Gravel Pit 41 <br /> February 2018 D-2 <br />