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The analyses of roof rock indicates that some plant growth problems may <br /> exist with the coal refuse. The roof rock material which commonly makes <br /> up a Large portion of the coal refuse is generally high in sulfur and <br /> iron, and has a high SAR. Therefore, the coal refuse may limit plant <br /> growth. Regulations require that coal processing waste embankments be <br /> covered with 4 feet of the best available non-toxic, non-combustible <br /> material unless the physical and chemical analyses characteristics of the <br /> coal processing waste would not limit plant growth. <br /> A plan was developed by the applicant and CMLRD to determine how much soil <br /> cover is required to meet the revegetation success standards (see TA) . <br /> The applicant proposes to strip topsoil from a borrow area near Mine No. 3 <br /> to place on the mine benches. Topsoil will be replaced on the mine <br /> benches to a depth of approximately 12 inches and the borrow area will be <br /> reclaimed. Based on previous revegetation at the mine, this should be <br /> sufficient to meet revegetation standards. <br /> Vegetation <br /> A reference area was located for each dominant affected area vegetation <br /> type. The three vegetation types for which reference areas were developed <br /> were aspen woodland, aspen shrubland, and spruce/fir parkland. However, <br /> during the course of the review, it was determined that the data collected <br /> from the undisturbed vegetation adjacent to the disturbed areas would be <br /> more representative than the reference areas. This data was collected on <br /> a much larger area than the reference area data. Therefore, it should be <br /> more representative of the disturbed areas than the reference area data. <br /> Revegetation success standards based on existing adjacent vegetation are <br /> required for the rock tunnel complex, coal refuse pile, the preparation <br /> plant area and the mine benches. The aspen shrubland vegetation type was <br /> chosen as being representative of the preparation plant and the coal <br /> refuse pile; the aspen woodland vegetation type was chosen as being <br /> representative of the rock tunnel complex; and the spruce/fir parkland <br /> vegetation type was chosen as being representative of the mine benches. <br /> See success standards in TA page 47. <br /> The revegetation plan calls for seeding predominantly native grasses and <br /> forbs. Several species of shrubs and trees will be transplanted. Two <br /> different seed mixes are planned to be used. The lower elevation mix for <br /> use at the preparations plant and rock tunnel consists of 14 grass <br /> species, 5 forb species, 8 shrub species, and 4 tree species. All the <br /> species in the lower elevation mixture are native. <br /> The high elevation mixture, to be used at the 5 mine sites, contains 16 <br /> grass species, 5 forb species, 7 shrub species, and 4 tree species. Only <br /> one introduced species, Timothy (Pleum pratense) , is included in this <br /> mix. CMLRD approves the use of this introduced species for the following <br /> reasons: 1) This species is necessary to establish quick cover, 2) the <br /> seeding rate is low (0.5 lb/acre) , 3) this species is compatible with <br /> plant and animal species of the region, 4) this species is not highly <br /> competitive at an elevation of 10,000 feet and will eventually be replaced <br /> by adapted native species, and 5) this species is not poisonous or noxious. <br /> -15- <br />