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Backfilling and Grading <br />This section addresses the requirements of 2.05.3(6), 2.05.4(2)(c) and 4.14. <br />Backfilling and Grading Methods <br />Mining and backfilling operations at New Horizon North (NHN) are performed concurrently. A <br />combination of cast blasting and shovel loaded trucks remove the overburden and parting <br />materials then haul the material to a previously mined area to be backfilled. <br />Along the crop line in the NHN Mine area, some box cut overburden material will initially be <br />temporarily stockpiled outside of the area mined (see Map 2.05.2-1). The box cut material will <br />be stockpiled in the south of the permit area and is available for backfilling at the end of mining <br />or at any other time to backfill the mining pit. The estimated volume of the overburden stockpile <br />is 900,000 bank cubic yards. All vegetative and organic material and topsoil will be removed <br />from the area where overburden material is to be placed. Both the overburden and topsoil <br />stockpile configurations are shown on Map 2.05.3(3)-3. The topsoil pile height is estimated to be <br />35 feet with a maximum 1.4H:1 V side slope. The overburden stockpile is estimated to be 75 feet <br />high with a maximum 1.4H:1 V side slope. These maximum side slopes represent the angle of <br />repose of the material. Stockpiles will be constructed to ensure stability of the fill and to comply <br />with the effluent limitations of Rule 4.05.2. The temporarily stockpiled material will be graded <br />into the mined area and hauled to the final pit area according to the reclamation plan. Map <br />2.05.4-1 illustrates the projected reclamation contours for the permit area. Since cast blasting, <br />truck, shovel and dozers will be used, backfilling operations will occur concurrently with mining <br />operations. Backfilled material will be placed to minimize effects on post -mining vegetation and <br />ground water, minimize off-site impacts and support the approved post -mining land use. <br />Approximately six months will be needed to complete the final backfilling operations in each of <br />the areas mined. Upon completion of the backfilling, all areas disturbed by mining will be graded <br />to a smoothed landform that approximates the existing, pre -mined landform (see Map 2.05.4-1). <br />Map 2.05.4-2 has 4 cross sections which show the pre -mining and post -mining land surfaces. <br />General Grading Requirements <br />Final Graded Slopes: Post -mining slopes will not be uniform but will approximate the general <br />nature of the pre -mining topography. All highwalls will be eliminated and graded to a 5:1 slope <br />or flatter. <br />Terraces: Terracing in the final reclamation is not proposed at the NHN Mine. <br />Small Depressions: Small depressions are not proposed at the NHN Mine. <br />Steep Slopes: NHN Mine does not have steep slopes as defined in the regulations. <br />Section 2.05.4(2)(c) Page 1 Sept. 2015 (TR -11) <br />