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• No box cut spoil grading is included in [his estimate. The timing and Location of the box <br />pit spoil is such that all box pit spoil wrll be reclaimed by the end of 2003, and <br />therefore, was no[ included as a liability in the "worst case" year. <br />Ramp grading estimates are included with spoil grading. It was assumed that ramps would <br />be graded at the same time as two spoils are pushed into the pit and, therefore, <br />additional cost is not estimated for this project. <br />Topsoil Replacement. Topsoil replacement volumes were based on the volume of material in <br />stockpiles at the end of year 2003. The estimated volume in each stockpile was based on <br />topsoil salvage depth per soil type over a particular area (acresl. In an effort to <br />arrive a[ realistic stockpile volumes, topsoil densities were measured in the field. The <br />material density, as measured in the stockpile, was 2516 LBS/CCY. According to <br />Caterpillar, the swell factor for this type of topsoil would be around 35 percent from BCY <br />to LCY. Assuming this material was compacted to 90 percent of its original density, the <br />original density would have been 2516 LBS/CCY divided by .90 2600 LBS/BCY. To arrive at <br />the LCY density, take 2600 LBS/BCY divided by 1.35 2075 LBS/LCY. All tables and <br />• calculations are based on these densities. Appropriate worksheets in At tachmen[ 25-1 shows <br />the topsoil balance Eor the mine area and the TAHR. FPC printouts in Attachment 25-2 list <br />the production time and cost associated with each topsoil stockpile. <br />The topsoil replacement cost estimate was completed with the aid of Caterpillar's Vehicle <br />Flee[ Production and Cost Analysis Program (FPC1. All FPC parameters are listed for each <br />project area. <br />Reveget anon <br />After the topsoil has been replaced from at ockpiles, the seedbed must be prepared prior to <br />seeding. This is accomplished by ripping and disking the seedbed. Seeding is principally <br />accomplished using a Rangeland drill. it was assumed that l0 percent of the area would <br />have to be mulched. Shrub and trees are also planted in designated areas in the <br />reclamation and reflected in the costs as shown here. All costs, including fencing, are <br />shown on appropriate worksheets in Attachment 25-1. Areas to be revegetated are shown on <br />the worksheets. A re vegetation failure rate of l0 percent was included for drill and <br />• broadcast seeded areas, a SO percent failure rate for shrub seeding areas, and an 65 <br />percent failure rate for shrvb/tree planting areas. <br />4 P,evised 3/01 <br />