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The specific species cited is Medicago Sativa, which is exactly the same as that prescribed in <br />the revegetation plan for irrigated cropland. Also, this reference does not differentiate between <br />• topsoil and subsoil. Since WFC is maintaining a limit of 4.0 in the topsoil (Lift A), the revised <br />limit of 6.0 mmhos/cm in the subsoil (Lift B) should be conservative. <br />3 Specific level depends upon clay mineralogy, soil texture, and saturation percentage <br />according to Dollhopf et al., 1983. <br />4 The specific percentage of clay or sand allowed will depend upon clay mineralogy, organic <br />matter content, consistence, soil lift, spoil characteristics, and size of sand fraction. <br />e These values may vary depending upon the plant species proposed for revegetation in <br />specific locations (e.g., a soil with a high coarse fragment content throughout its profile may be <br />completely salvaged if used for rangeland versus cropland postmine land use). Prime farmland <br />will not have >10% cobbles and boulders (3 inches mean diameter and greater) and 15% <br />coarse fraction (caught in a 2 millimeter sieve) by volume. The % volume is estimated visually. <br />• 6This value for selenium was chosen based on guidance from Dave Dearstyne of NRCS and <br />recent data that other states are using. Dave is currently working extensively (2008) with the <br />Selenium Task Force on the western slope and is very knowledgeable about this issue. He <br />basically stated that there is no concern for selenium unless Mancos shale strata is being <br />placed near the surface. At the new Horizon #2 Mine, no Mancos shale is placed near the <br />surface. Also, all tests of selenium in the pre-mine soil survey of 1998 show all values less than <br />0.1 ppm. The suitability report of the bench 1 material used as subsoil on the previously <br />backfilled portion of the Morgan property in early 2008 show <1 ppm in all tests. Dave <br />Dearstyne believes a threshold suitability level of 0.2 ppm in the Lift A material and 1.0 ppm in <br />the Lift B material is adequate. These are the levels proposed. <br />In cases where the Bench 1 material is used as the Lift B soil in prime farmland, it will meet the <br />specifications for Lift B, as outlined in Table 2.04.9-2. <br />0 (Revised Nov 2008) Attachment 2.05.4(2)(d)-1-17