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and 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 P.E 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 /> constructed 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 10 -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 /> or no potential to adversely affect water quality, flows or vegetation; create public health hazards; or cause
<br /> instability in the CRDA Expansion area.
<br /> TR09 -67 2.05 -97.4 11/10/09
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