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Partial mixing of alkaline and acidic materials is anticipated during cast blasting, dozer pushing, <br />and shovel /truck handling due to the thinness of Units 2 and 4 and the stratification of alkaline <br />and acidic strata. Normal overburden /interburden handling operations may also effectively bury <br />the acid - forming strata. <br />Typical overburden /interburden handling operations are described in Section 2.05.3, Operation <br />Plan and Section 2.05.4(2)(c), Backfilling and Grading. <br />The mine sequence is to first remove the topsoil (Lift A and B or Mixed) with the truck - shovel <br />fleet and hauled it to the regraded area behind the pit to be spread or stockpiled. A temporary <br />haul road around the end of the pit is used for this operation. In some cases, the topsoil is <br />temporarily pushed in advance of the pit in a temporary elongated moving stockpile, which is <br />eventually loaded and hauled to the regraded backfill for permanent or temporary placement. <br />As described in Small Area Exemptions, a small topsoil catchment berm /ditch is placed at the <br />advance edge of the pit so that all surface water runoff (precipitation or snow melt) from the <br />topsoil excavation area is trapped by this berm. Soft upper overburden (Bench 1 or Unit 1 <br />material) is normally removed by the truck - shovel fleet and taken to the back of the previous pit <br />for backfilling using the same temporary road around the end of the pit. A significant amount of <br />this Bench 1 material is normally placed immediately below the Lift A, Lift B or Mixed topsoil in <br />all areas. The amount varies per area, however, the total amount of topsoil and suitable subsoil <br />will be approximate 4 feet thick, except in the WFC property on the west side of the permit, as <br />described earlier, which will be at least 3.5 feet thick. The Bench 1 material thickness does <br />decrease going westward and WFC will attempt to utilize all the suitable Bench 1 to get the <br />required thicknesses specified above. <br />Lower overburden (Bench 2) is usually cast blasted, dozed and loaded /hauled with <br />shovel /trucks and placed in the previous mined out pit for backfilling purposes. As the <br />overburden trucks dump off the backfill spoil dump, large dozer(s) will final grade the truck <br />dump area into the final pre topsoiled contours. <br />Lastly, ameliorating reclamation practices will primarily be utilized in those areas where <br />unsuitable spoil reaction, acid -base potential, particle size, saturation percentage, salinity, <br />(Revised October 2009) 2.05.4(2)(d) -8 <br />