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Similar to the planned soil handling operations described, TC will also recover, stockpile, and replace suitable
<br />cover materials to meet the applicable regulatory standard of 4 feet of suitable cover over the regraded coal refuse
<br />materials. Engineering projections indicate that a maximum of approximately 253,500 cubic yards of soil material,
<br />end 571,600 cubic yards of suitable cover material will need to be recovered and replaced during the life of the
<br />CRDA Expansion. Soil and cover material handling operations are summarized by Table 49A, Soil Stockpile
<br />Summary, and in Exhibit 26C. Both soil and cover material stockpiles will be placed, graded, and stabilized to
<br />prevent loss or contamination of these materials, and to minimize erosion potential. Potential runon and runoff
<br />from the piles will be controlled by a closed system of ditches and berms, and the piles will be stabilized by seeding
<br />with a rapid - germinating temporary cover seed -mix (refer to Table 54, Cropland Seed Mix). Soil stockpiles will be
<br />posted with identifying signage, which will be maintained so long as material remains in the stockpile(s).
<br />Construction of the Coal Refuse Haulroad will proceed simultaneously with soil and cover removal operations for
<br />the refuse toe bench. The proposed haulroad will be approximately 2,300 feet long, with a traveled surface
<br />approximately 30 feet wide. Following soil material removal from the road alignment, the road footprint will be
<br />scarified and cut/fill operations will establish the general road configuration, as shown in the design documentation
<br />provided in Exhibit 26C, Coal Refuse Disposal Area Expansion Designs. Fills will be placed and compacted in
<br />uniform lifts of 6 -8 inches. The road surface will consist of approximately 6- inches of well - graded aggregate base,
<br />overlain by approximately 18- inches of pit run road base materials, compacted to 95 percent of maximum dry
<br />density. Road drainage will be addessed by designed ditches and culverts, sized to safely pass the runoff from the
<br />10 -year, 24 -hour storm event. Design documentation and the required RE certification for road designs are
<br />presented in Exhibit 26C, Coal Refuse Disposal Area Expansion. The Coal Refuse Haulroad will provide for
<br />material haulage from the Coal Refuse Hopper(s) to the CRDA Expansion area. Haulage within the CRDA
<br />Expansion area, including haulage on benches, will occur on temporary roads established within the CRDA
<br />footprint and typically on established refuse fill areas.
<br />Following soil material removal, construction will begin on both the perimeter drainage control ditches and the
<br />CRDA toe drain. Because the CRDA Expansion will be constructed in phases, initial perimeter ditches will be
<br />, onstructed as temporary ditches, designed to safely pass the runoff from the 10 -year, 24 -hour storm event.
<br />Permanent perimeter ditches have been designed and will be constructed to safely pass the peak flows from the
<br />100 -year, 24 -hour design storm event. In order to control flow velocities and facilitate vegetative reestablishment
<br />in the permanent perimeter ditches, temporary rock check -dams may be constructed in these ditches in accordance
<br />with the design parameters previously outlined for the existing CRDA. Because infiltration through the pile to the
<br />CRDA Expansion foundation area would occur gradually over time, regardless of storm event, the toe drain has
<br />been designed based on the l0 -year, 24 -hour precipitation event. The toe drains primary purpose is to prevent any
<br />significant build -up of hydrostatic pressure within the pile, which could affect pile stability. Based on design
<br />calculations, the required toe drain would consist of durable 9 -inch rock with a cross - sectional area of
<br />approximately 50 square feet, enclosed by graded cover material to minimize the potential for fines infiltration and
<br />plugging. Drainage from the intermediate pile benches and the surface of the pile (both during construction and on
<br />completion) will be controlled by sloping benches and the pile surface away from the outslope, with the benches
<br />connecting into the perimeter drains along the margins of the pile. All drainage structures will route drainage to
<br />existing Pond D, which will continue to operate in compliance with applicable effluent standards. Designs for
<br />drainage structures associated with the CRDA are presented in Exhibit 8EE — Coal Refuse Disposal Area
<br />Expansion — Drainage Designs.
<br />Similar to the existing CRDA, the CRDA Expansion is designed to accommodate both temporary (winter)
<br />placement and permanent disposal of coal refuse materials generated by ongoing underground development and
<br />mining operations, and operation of the TCC coal preparation facilities. The coal refuse materials to be placed in
<br />the expansion area are essentially the same as the materials that have been placed in the existing CRDA, and have
<br />similar physical and chemical characteristics (ie: non -toxic and non -acid, refer to Table 20A, Waste Material
<br />Analyses). For the CRDA Expansion, coal refuse materials would continue to be hauled from the Foidel Creek
<br />Mine Facilities Area or the potential future Sage Creek Project Area, and placed in a controlled manner on the
<br />refuse pile using either TCC's existing mobile equipment fleet or contractor equipment. Any refuse materials
<br />hauled from the future Sage Creek operations and placed in the CRDA Expansion area, will be transported on
<br />existing designed haulroads and the County Road (RCR27). These materials will come from the same geologic
<br />units that are mined or affected at the Foidel Creek Mine, and therefore, will have similar characteristics, with little
<br />TR13 -83 2.05 -97.4 05/14/14
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