2018-05-25_PERMIT FILE - M1995004 (4)

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Exhibit D MINING PLAN Unless specifically discussed below the methods described in the January 1995 application for the mining and reclamation plans will remain unchanged. The following text is the same as provided in 1995 with additions, to update and/or address the changes being added to the permit with this amendment . There is no current bond because the mine is operated by an arm of Grand County Government . A new reclamation cost estimate is presented in Exhibit Lon of this application for your review. The following changes to the mining plan are numbered sequentially to give some order to this amendment . 1995 Mining Plan History of the Pit The mine started in as a 5 . 0 acre site that was expanded in 1995 to 19 . 99 acres . The original pit abuts a steep west facing slope on the east side of the permitted area. Prior to the 1995 expansion, the operation involved mining straight into the talus slope on the east side until solid rock was encountered. As additional material then slid down the steep undermined slopes that material would also be removed. This resulted in the creation of a steep rock faced highwall approximately 50 tall . Mining then progressed to the south along the highwall . This was changed in 1995 when the county started placing some of the overburden against the base of the highwall to slope the east side so there were 2 : 1 or flatter slopes along that side. In 2011 mining moved into a more southern direction that resulted in the east side slope being mined at a flatter more stable rate and backfilled and shaped as mining progressed. Mining Method to be Employed The existing pit is approximately 19 . 99 acres in size. The pit will be expanded to a total of 29 . 61 acres ± . The potential mineral material reserves of rock and soil in the new area, is approximately 200, 000 cubic yards . The plan is to remove approximately 20, 000 cubic yards per year for 10 years . Mining reached the southern limits of the gravel deposit in 2017 . As noted in the permit Grand County will not mine any further into the eastern hillside creating a highwall . The materials piled up against the base of the existing highwall have been slope to 2 : 1 or flatter as approved. Mining will resume on the south facing slope on the north end of the mine and remove the finger of gravel that extends along the south side of an ephemeral drainage that defines the north part of the mine area. The gravel fan from the mouth of the ephemeral drainage will also be removed down to an elevation consistent with the existing floor of the old mine area. The east side will be sloped to blend with the natural slopes on the east hillside . This will move the toe of the final slope closer to the east boundary and leave slopes in that area 2h to 1 or flatter. This will create a natural looking transition from the steeper slopes on the east to the gently sloping mine floor. The maximum seam thickness to be mined will be 25 - 301 . No mining will occur on slopes which are 4