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The New Horizon 2 postmine spoil textures will typically be loamy with an approximate particle <br />size distribution of 65 percent sand, 25 percent silt, and 10 percent clay (Section 2.04.6, <br />Geology Description). Surface crusting, which is critical to seedling emergence, is discussed in <br />the Soil Survey (Section 2.04.9), Revegetation Plan (Section 2.05.4(2)(e)), and Topsoil <br />Management of this Section. Since clay percentages and shrink -swell potentials are low, <br />stability and trafficability problems are not anticipated. <br />The resultant loamy textured spoil will possess suitable physical qualities which are conducive <br />to plant growth. The available water holding capacity will likely be moderately low to moderate <br />(approximately 0.07 to 0.11 inches of water per inch of soil), permeability moderate to <br />moderately rapid (about 1.0 to 6.0 inches per hour), and cation exchange capacity low to <br />moderately low (5 to 10 milli - equivalents per 100 grams). Since the overburden contains a <br />mixture of soft, slightly hard, hard, and extremely hard rock fragments, the spoil will generally <br />possess acceptable root growth and water holding characteristics. <br />The chemical properties of the overburden /interburden are also quite favorable. Sodicity and <br />salinity levels are low to moderate in the New Horizon 2 permit area and should pose no severe <br />problem to successful reclamation. Salinity levels in the upper four feet of regraded spoil will <br />likely be comparable to premining values. <br />The uppermost overburden transitions into the subsoil gradually on the majority of the permit <br />area. Much of this upper overburden (also called Bench 1 material) is suitable subsoil. For the <br />area west of 2700 Road, it is standard practice that suitable Bench 1 substitute subsoil material <br />will be used to supplement the subsoil to provide the best chance for reclamation success. The <br />topsoil replacement calculations discussed later in this Section accounts for the use of some of <br />this suitable material. <br />Revised September 2010 (PR 06) 2.05.4(2)(d) -11 <br />