2018-09-11_PERMIT FILE - C1981008A (15)

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Backfilling and Grading Backfilling and Grading Methods Mining and backfilling operations at the New Horizon Mine will be performed concurrently. Scrapers and/or shovel loaded trucks will remove the overburden and parting materials, then haul the material to a previously mined area to be backfilled. Along the cropline in the New Horizon Mine area, some box cut overburden material will initially be temporarily stockpiled outside of the area mined (see Map 2.05.3-1). This box cut material has been stockpiled in a borrow pit near the southeast corner of the permit area and is available for backfilling at the end of mining or at any other time to backfill the mining pit. All vegetative and organic material and topsoil will be removed from the area where overburden material is to be placed. The temporarily stockpiled material will be graded into the mined area and hauled to the final pit area according to the reclamation plan. Map 2.05.4-1 illustrates the reclaimed land contours for the years 1993 to 2007 as well as the projected reclamation contours for years 2007-2019. Since scrapers, trucks and dozers will be used, backfilling operations will occur concurrently with mining operations. No draglines will be used. Backfilled material will be placed to minimize effects on post -mining vegetation and ground water, minimize off-site effects and support the approved post -mining land use. Upon completion of the backfilling, all areas disturbed by mining will be graded to a smoothed landform that approximates the existing, pre -mined landform (see Map 2.05.4-1). This map also has cross sections which show pre -mining and post -mining land surfaces. General Grading Requirements Final Graded Slopes. Postmining slopes will not be uniform but will approximate the general nature of the pre -mining topography in order to achieve the approved postmining land use. All highwalls will be eliminated and graded to a slope of 3H:1 V or flatter. Some localized areas within the regrade areas may have slopes slightly greater than 3H:1V. See Map 2.05.4-1, Postmining Topography for plan view and cross-sections of the postmining final regrade surface. Terraces. Terracing in the final reclamation is proposed only in the area of the former BB Detour Road. See Map 2.05.4-1, Postmining Topography for the location of these rock terraces. Small Depressions. Small depressions are not proposed at the New Horizon Mine with the exception of the restoration of the depression at Pond 014. The pre -mine landscape shows this depression. After mining, this depression is restored and Pond 014 no longer exists. This pond handles a small drainage area which flows into the depression. Page 2.05.4(2)(c)-1 July 2018 (TR -84)