2010-06-25_PERMIT FILE - C1981019A

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RULE 2 PERMITS 4. Vegetation material in the topsoil will increase organic matter and thereby encourage microbial activity, and speed natural soil building processes. It is very unlikely that mixing the vegetation with topsoil could adversely effect reclamation. The determination of the amount of any fertilizer to be applied will be determined as per the Soil Testing Program. The vegetative material that could be large enough to interfere with topsoil operations refers to the large Gambel's Oak and Aspen. The larger trees are not crushed as is the smaller brush during the course of topsoil removal, stockpiling and/or redistribution by dozers, loaders, trucks and scrapers. Once handled by the equipment, the smaller brush causes little problem during later phases of the topsoil or reclamation operations. When removed by dozers, the topsoil is pushed into piles and loaded into haulage trucks for transport to stockpiles or regraded spoils. In addition to haulage to remote stockpiles, topsoil windrows may be left in place at the edge or perimeters of disturbance areas. Dozers or scrapers are used to redistribute topsoil. Topsoil stockpiles will be strategically located in stable areas to avoid both wind and water erosion, disturbance, unnecessary compaction, and contamination. In addition, topsoil stockpiles will be appropriately marked with conspicuous signs made of durable material. When stockpiles are no longer active, they will be graded with a dozer. To further prevent erosion, seeding of stockpiles will be accomplished according to procedures described in Section 2.05.4. Topsoil removal schedules and stockpile locations are delineated on the Topsoil Handling Map, (Map 28 and 28A). The amount of topsoil in stockpile and the amount projected to be available for redistribution are summarized on Table 2.05-1. This balance calculation shows that sufficient topsoil is available. Replacement depth for future lands is discussed in Section 4.06.4. Maps 28 and 28A show the mature nature of the mining operation, with a substantial quantity of land already covered with redistributed topsoil and a relatively small amount of future topsoil stripping areas. Topsoil will be removed from an area primarily during the summer and fall months to allow for one year's mining advance. A buffer zone, with topsoil removed, will be left between the undisturbed area and the crest of the pit. Following topsoil removal, the next step is drill bench preparation and the drilling and blasting of the overburden material. Colowyo maintains and operates several rotary drills for penetrating the overburden and interburden material. Dozers are used to construct a drill bench, a level area for the drill to work on. The overburden drill then drills a pattern of holes to either a predetermined sub-grade depth or to the top of the coal seam. The spacing of the holes will be dependent upon the overburden thickness, but usually will be in the range of 25 feet by 25 feet. Holes will be loaded with either ANFO or a waterproof explosive, if the hole is wet, to a typical powder factor of between 0.5 and 1.2 pounds per bank cubic yard. The hole will then be stemmed with drill cuttings and blasted in accordance with detailed descriptions given in Section 2.05.3 under the heading of Overburden. Currently, a Bucyrus-Erie 1300W dragline and a Marion 8050 dragline are used for overburden removal over the lower coal seams; a third dragline, a Bucyrus-Erie 800W, is sometimes used to supplement the capacity of the BE 1300W or Marion 8050 machines in the multi-seam scenario, and by itself in single seam operations. The generalized multi-seam dragline sequence at the Colowyo operation is as follows: The Bucyrus-Erie 1300W and Marion 8050 draglines begin the sequence removing the overburden over the "B", "C", and "D" seams in a single sidecast mode, spoiling the Rule 2 Permits 2.05-2 Revision Date: 6/23/08 Revision No.: MR-91