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• Area 1: Most of the Whirlwind portal area was previously reclaimed without placing topsoil; <br />accordingly, there is only a limited amount of topsoil that can be salvaged from the previously <br />reclaimed area. Almost all of the salvageable topsoil in this area occurs on the slope of the reclaimed <br />waste pile, which covers about 1.6 acres. This material will be stripped to a depth of 6 inches and will <br />be placed in the Whirlwind stockpile on the north side of 5/10 Road (Stockpile #1). This represents <br />about 1,300 cubic yards of topsoil. The existing growth media on top of the waste pile pad will also be <br />salvaged and placed into the Temporary Topsoil Stockpile on top of the waste pile. <br />Area 2: The waste embankment will expand east over Area 2, which is relatively flat with gentle <br />slopes. Most of the soil borings were completed in this area, where topsoil ranges from 1.2 feet to 2.3 <br />feet in thickness. There are a number of rock outcrops in the area where no topsoil is available. Based <br />on the collected soil samples, the average topsoil thickness in this area is 1.78 feet. When the rock <br />outcrops are subtracted, the average thickness is estimated to be 1.6 feet. Since the area is 8.42 acres in <br />size, the volume available for stripping is 21,700 cubic yards. Initially, only about 5,900 cubic yards <br />will be stripped and placed in Stockpile #1, located north of 5/10 Road, for use in final reclamation. <br />• The stockpile will have 3H:1 V sideslopes. A smaller stockpile will exist on the portal bench as shown <br />on Map C-2 (Temporary Topsoil Stockpile, a.k.a., Stockpile #3). This area will have the same 3H:1 V <br />sideslopes and will contain approximately 3,900 cubic yards of topsoil stripped prior to future <br />advances of the waste embankment. Subsequent topsoil stripping will be used to contemporaneously <br />reclaim previously regraded areas of the waste embankment. <br />Area 3: Area 3 comprises the steeper slopes along the south edge of the waste embankment expansion. <br />Soil boring 5 with a topsoil thickness of 1.2 feet was completed at the base of this slope. No borings <br />were completed higher up on the slope, but based on a visual inspection, it is apparent that this area has <br />a thinner soil cover than Area 2. For estimating purposes, a soil thickness of 0.8 feet is assumed, which <br /> <br />results in an estimated topsoil volume of 3,000 cubic yards over the 2.36 acre area. <br />Area 4: This area is north of 5/10 Road and will contain the treatment plant and various tanks, and the <br />Sediment Pond. No soil borings were completed in this area, but the area is similar in grade and land <br />form to Area 2. An average topsoil thickness of 1.6 feet is assumed for Area 4. Since the area is 1.71 <br />acres, the topsoil volume available for stripping is estimated to be 4,400 cubic yards. The majority of <br />Whirlwind Mine 07 (rev. April 08) D-18 <br />