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• When removed by dozers, the topsoil is pushed into piles and loaded into haulage trucks for <br />transport to stockpiles or regraded spoils. In addition to haulage to remote stockpiles, topsoil <br />windrows may be left in place at the edge or perimeters of disturbance areas. Dozers or <br />scrapers are used to redistribute topsoil. Topsoil stockpiles will be strategically located in <br />stable areas to avoid both wind and water erosion, disturbance, unnecessary compaction, and <br />contamination. In addition, topsoil stockpiles will be appropriately marked with conspicuous <br />signs made of durable material. When stockpiles are no longer active, they will be graded <br />with a dozer. To further prevent erosion, seeding of stockpiles will be accomplished <br />according to procedures described in Section 2.05.4. <br />Topsoil removal schedules and stockpile locations are delineated on the Topsoil Handling <br />Map, (Map 28 and 28A). The amount of topsoil in stockpile and the amount projected to be <br />available for redistribution are summarized on Table 2.05-1. This balance calculation shows <br />that sufficient topsoil is available. Replacement depth for future lands is discussed in Section <br />4.06.4. Maps 28 and 28A show the mature nature of the mining operation, with a substantial <br />quantity of land already covered with redistributed topsoil and a relatively small amount of <br />future topsoil stripping areas. <br />Topsoil will be removed from an area primarily during the summer and fall months to allow <br />for one year's mining advance. A buffer zone, with topsoil removed, will be left between the <br />undisturbed area and the crest of the pit. <br />Following topsoil removal, the next step is drill bench preparation and the drilling and <br />• blasting of the overburden material. Colowyo maintains and operates several rotary drills for <br />penetrating the overburden and interburden material. Dozers are used to construct a drill <br />bench, a level area for the drill to work on. The overburden drill then drills a pattern of holes <br />to either a predetermined sub-grade depth or to the top of the coal seam. The spacing of the <br />holes will be dependent upon the overburden thickness, but usually will be in the range of 25 <br />feet by 25 feet. Holes will be loaded with either ANFO or a waterproof explosive, if the hole <br />is wet, to a typical powder factor of between 0.5 and 1.2 pounds per bank cubic yard. The <br />hole will then be stemmed with drill cuttings and blasted in accordance with detailed <br />descriptions given in Secticn 2.05.3 under the heading of Overburden. <br />r1 <br />L..J <br />- 2.05-3 Revision Date: 11/02/05 <br />Revision No.: TR-62 <br />