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Eolian sands are intermixed with Cretaceous Dakota and Burro Canyon Formations in map unit <br />98G. Soil is generally moderately deep with significant inclusions of shallow soil on convex <br />slopes. Soil salvage in this map unit may yield slightly less than predicted. <br />Map unit 98H occurs on mesa side slopes that are not as steep as those found in map unit 98B. <br />Hardness of bedrock varies depending on the underlying strata. Wahweap soil has the same <br />physical and chemical properties as those soils similarly named in the survey area. Wahweap is <br />outside the range of characteristics compared to the survey area, in that it occurs in an area of <br />7 inches mean annual precipitation. <br />Table 2.04.9 -3 represents average depths and pH of lift layers for soil salvage materials in the <br />1998 survey area and which lie in the proposed future area of disturbance as of February 2008. <br />Weighted average lift depth is based on the percent of each soil component including inclusions <br />for each map unit. Appendix 2.04.9 -9 lists the percent composition for each soil type in a map <br />unit. Weighted average lift depths are used to calculate volume of salvage material in table <br />2.04.9 -4. Lift layer A is a combination of the following horizons where present: A, Ap, Ag, AB, <br />AC, Bw, and Bt if the pH of those horizon was less than 8.0. Lift layer B is a combination of the <br />following horizons where present: AC, Bw, and Bt if the pH of those horizons was greater than <br />8.0 and Bk, Btk, and C horizons. The volumes are shown for a) the full thickness reported from <br />the soil survey and also b) 80% or 90% of the thicknesses from the soil survey, depending upon <br />wether the soils are prime or not. For prime soils, a 90% recovery is used. For non -prime soils, <br />an 80% recovery is used. This reduction is, in most cases, realistic, since the soil survey points <br />do not show some rocky areas that exist between sample points, thickness variations that <br />cannot be fully stripped in the field, and other constraints that occur with large equipment. <br />Table 2.04.9 -4 represents the acreage by map unit and the weighted average volume (cubic <br />yards) of soil salvage material by lift layer available in the 1998 soil survey area and which lies <br />in the disturbance area. Soil map unit 98B and 98H and all soil units north of BB Road and <br />west of and including the mine pit are combined into one lift layer for all horizons as cited in <br />2.05.4(2)(d). <br />(Revised October 09) 2.04.9 -28 <br />