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The highwall reduction area and spoil will be worked together to shape and blend the material into the <br />natural topography, creating a transition that prevents drainage from creating knickpoints, propagating <br />natural undisturbed slopes, and enhancing the postmining land use. <br />The postmining topography in the North Valora Pit has been modified to accommodate both ongoing <br />backfilling and grading in this area and establishment of the alternate haulroad necessary to replace the <br />lower portion of Haulroad D, which has been impacted by the stability problems above Pond 012. The final <br />slope configuration in the lower portion of the North Valora Pit will be completed in 2006 when the <br />haulroad is removed and the lower end of Channel YPM-6 is constructed (the material removed from the <br />haulroad and channel will need to be placed against the northern sideslope to achieve PMT). See Exhibit <br />19-1A, Backfilling and Grading Plan, for location of this variance area and reclamation schedule. <br />The localized changes in postmining topography result in steepening (from approximately 4.9:1 to 3.5:1) of <br />an 800, section of the slope along the north highwall, but generally maintains the overall gradient of <br />Postmining Channel YPM-7. The new 3.5:1 slope is well below the natural angle of repose for spoil <br />materials, is compatible with the objective of long-term slope stability and existing natural slopes in <br />the area, and meets the applicable general grading requirements of Rule 4.14.2(1)(b). <br />SCC recognizes that post -reclamation natural settlement has the potential to result in limited exposure of <br />portions of the North Valora Pit highwall. SCC will address the settlement and highwall exposure concern <br />by monitoring this area for settlement, surface cracks, and any highwall exposure. It is anticipated that <br />any surface cracks or highwall exposure that may occur will be localized and of limited extent and can be <br />repaired by minor regarding and reseeding. <br />Thin or thick overburden as defined by Section 4.14.4 and 4.14.5 does not exist at the Yoast Mine. The <br />final volume is greater than 0.8 of the initial volume, therefore the thin overburden criteria is not <br />applicable. The thick overburden rule does not apply because the final volume is not greater than 1.2 of <br />the initial volume. Please refer to the volume calculations on Table 20.1, Postmining Landform Mass <br />Balance. <br />Box cut spoil will initially be placed onto un -mined land as described in Tab 12. This material will be <br />re -handled when the dragline returns to the box cut area(s). Portions of box cut spoil will be <br />temporarily stored in approved locations above the highwall for backfill into portions of the final pits. <br />All vegetative and organic material and topsoil will be removed from the area where box cut spoil is <br />placed, and the spoil graded both into the mined area and blended into the surrounding terrain. No <br />material shortages or excessive disturbed areas are anticipated in the area of the final highwall or major <br />spoil excesses in the box cut area. This can be determined by reviewing Exhibit 12-1, Operations Plan, <br />and the pre- and postmining topography slopes as shown on Exhibits 20-2A, Pre- and Postmining Cross - <br />Sections. <br />PR -02 2 Revised 03/05 <br />