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Map unit 98F occurs in natural drainage areas that eventually form shallow valleys on the mesa and <br />on the low lying area near Tuttle Creek. Depth to bedrock varies widely in this map unit. Haplargids <br />with varying depths to bedrock form on drainage side slopes. Endoaquepts are formed where <br />irrigation water has accumulated in drainage bottoms. In a few naturally occurring areas of water <br />accumulation Endoaquolls have formed. <br />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 slopes. <br />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 7 <br />inches mean annual precipitation. <br />Table 2.04.9 -3 represents average depths and pH of lift layers for soil salvage materials in the 1998 <br />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 unit. <br />Weighted average lift depths are used to calculate volume of salvage material in table 2.04.9 -4. <br />Lift layer A is a combination of the following horizons where present: A, Ap, Ag, AB, AC, Bw, and <br />Bt if the pH of those horizon was less than 8.0. Lift layer B is a combination of the following <br />horizons where present: AC, Bw, and Bt if the pH of those horizons was greater than 8.0 and Bk, <br />Btk, and C horizons. The volumes are shown for a) the full thickness reported from the soil survey <br />and also b) 80% or 93% of the thicknesses from the soil survey, depending upon wether the soils <br />are prime or not. For prime soils, a 90% recovery is used. For non -prime soils, an 80% recovery <br />is used. This reduction is, in most cases, realistic, since the soil survey points do not show some <br />rocky areas that exist between sample points, thickness variations that cannot be fully stripped in <br />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 yards) <br />of soil salvage material by lift layer available in the 1998 soil survey area and which lies in the <br />(Revised July 2010) 2.04.9 -21 <br />