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....~:; <br />Predecisional Draft ~ ,: . _ ',;„,~ ~;g1~~12/28/94 <br />Kerr Coal Company -Man Strip - •" ''' <br />II~~.a <br />.l'.V •L <br />proposed postmining slope of 15 degrees occurs in the Pit 1 area and matches <br />the premining topography. <br />The proposed postmining contours were estimated by an evaluation of the pit <br />volumes, comparison of these with a volume estimated for swelled overburden <br />to be backfilled in designated pit areas. Also, overburden in an existing <br />overburden stockpile was proposed to be used to backfill the existing pit and <br />the final pit in Pit 3, and was so considered in the evaluation. The volume of <br />overburden, which is anticipated to be in excess of the pit volumes, was <br />distributed over the pit area to approach approximate original contours. The <br />applicant provided calculations, maps, cross-sections and descriptive <br />commentary on the methodology used for each stage of this analysis. The data <br />are summarized in Table 74a. The volume of the existing stockpile was <br />checked using aerial photos. <br />Excess Spoil. Deficient Spoil. Impoundments <br />Regulations applying to excess spoil may be employed where the final <br />thickness is greater than 1.2 of the initial thickness. This condition does not <br />apparently exist at any part of the Man Strip {)1 Mine. Therefore, these <br />regulations are not applicable. <br />Regulations applying to deficient spoil may be employed where the final <br />thickness is less than 0.8 of the initial thickness. This condition does not <br />apparently exist at any part of the Man Strip Mine N1. Therefore, these <br />regulations are not applicable. <br />No permanent impoundments are proposed to remain after mining is complete. <br />Contemporaneous Reclamation <br />The applicant states that, "All reclamation activities including, but not limited <br />to, backfilling, grading, topsoil replacement and revegetation will be carried <br />out as contemporaneously as practicable with mining operations" (pg. 816-123 <br />of the permit application). <br />Due to the steeply dipping nature of the coal seam, open-pit mining methods, <br />as proposed (and have been used at the existing mine for coal recovery) will <br />require up to two years before backfilling of Pits 1 and 2. Due to the large <br />proposed size of the steady-state pit in Pit 3, some mined-out areas may not be <br />3 <br />