PERMFILE103109

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 7/19/2002
• Doc Name: pages 2.05-1 to 2.05-100.1
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: Yes

RPR. 9.2002 10~07RM TWENTYMILE CORL ENVIRONMENTRL
N0.871
area. The access road follows relatively level terrain and will be gravel surfaced, so access road drainage control
requirements are minimal. All drainage calculations and documentation is provided in Exhibit SS, the SAE
demonstration is provided later in this section, sad the drainage structures are shown on Map 24. The SAE
demonstration includes ditch sizing for the upland diversion ditch and road ditch.
The access road into the shaft pad crosses Fish Creek, and,TCC will place "Buffer Zone" signs at the botmdary of
the stream crossing disturbance. Except for the disturbance associated with the stream crossing no further activity is
planned within the Buffer Zone boundary,
Construction of the ventilation shaft access road involves topsoil recovery and windrowing or stockpiling,
installation of required drainage structures, scarification and re-compaction of surface roatarisls, placement of
geotextile in selected areas, and placement and compacting of approximately 8" of pit-run gravel and 3" of road-
base material. The access mad surface will be approximat~ejly 22' wide and will be graded anti crowned to promote
effective drainage. Road construction requlras minimal cut, and limited fills in the area of the Fish Creek drainage
crossing. Fill slopes wi116e graded to a 3H:1V and stabi]'ized by seeding with the topsoil stockpile stabilization
seed mixture. Preparation of the ventilation shaft pad ini~olves topsail recovery and stockpiling, installation of
required drainage structures, grading and compaction to establish a level pad working area, excavation of mud pits
for drilling of the shaft pilot hole, temporary stockpiling of the excavated material, and placement of gravel
surfacing material to control dust and sediment from the pad area. Mud pits will be approximately 20' x 20' x 8'
deep and are sized to contain all drilling fluids. Tn the event unanticipated ground water flow into the boring is
encountered they the pits maybe enlarged or additional pitw' excavated to handle the flow.
The ventilation shaft pilot hole will ba drilled using a reverse circulation drill rig to drill a la" nominal diameter
pilot hole from the surface to a depth of approximately 1450'. The shag collar area will be excavated to a depth of
approximately 20', a collar liner, consisting of steel ring beams and Diner plate will be placed, and the annulus
between the liner and the collar excavation cemented. A temporary head-frame will be erected on the shaft collar
structure over the pilot hole to support and handle the shaft boring equipment. The shaft boring drive unit will be
installed on the shaft collar structure in preparation for shaft boring operations. During drilling, all drilling fluids
will be contained in the excavated mud pits and drilling fluids are generally recirculated. Shag boring and casing
of the approximate 20' diameter ventilation shaft are condµcted as separate operations. A surfaco-mounted drive
unit is used to rum a rotary cutting head attached to a shaft extending from the surface through the pilot hole, and a
hoist on the temporary headframe is used to maintain continuous upward pressure on the Dotter head. As baring
progresses, the cuttings are drgpped down the shaft bore add are recovered, transported, and placed in mined-out
areas underground. An alternate to transporting the cuttings~to mined-out areas will be to slurry them into the EMD
sump. An underground lice will be installed and the cuttings slurried to the BMD and pumped behind the seals in 7,
9 or l O Right. Once the cutter tread breaks through to the sui face within the shaft collar, the auttar head, drive unit,
and temporary headframe will be disassembled and tamove$ from the site. A permanent shaft Dosing consisting of
steel ring beams and liner plate will be placed and the annulus between the liner and the shaft bore will be cemented
is segments after boring operations progressed to the surface.
The cement shaft liner will serve to isolate the Twantymile $aadstone from the Wadga Overburden. Additionally, it
is planned to pressure grout the TWentymile Sandstone to prevent seepage from it into the shaft. This will further
ensure that after final closure the water in this unit will be coafmad and not seep down on the inside of the shaft.
Following completion of shaft boring and casing operatigns and removal of equipment from the site, the fan
enclosure (fan shmgd) and electrical control building will >ta erected on either the previously constructed or new
concrete pads acrd the fan, fan drive motor, and electrical conirol, monitoring, sad communication systems will be
installed. Average pad thickness will be 2' and total pad surface area will be approximately 3100sf. The installed
axial-vane exhausting ventilation fop has a capacity of 800,000 cfm with a 3000 hp drive motor. A fence will ba
constructed to enclose the fan installation. Following commissioning, the shag pad site and access mad will be
cleaned-up and surface ernes graded and dressed
MR 02-178 2.05-45.1 04/08/02