2010-06-04_PERMIT FILE - C1982056A ‎(9)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 6/4/2010
• Doc Name: Pages 2.05-1 to 2.05-64
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: Yes

this section, and the drainage structures are shown on Map 24. The SAE demonstration includes ditch sizing for the
upland diversion ditch and road ditch.
Construction of the ventilation shaft access road will involve topsoil recovery and windrowing, installation of
required drainage structures, scarification and re- compaction of surface materials, and placement and compaction of
approximately 8 inches of pit -run gravel and 3 inches of suitable road -base material. The access road surface will
be approximately 24 feet wide and will be graded and crowned to promote effective drainage. Road construction
requires minimal cut and limited fill, so the actual road disturbance area will average approximately 35 feet wide.
Cut slopes will be established at a maximum of 1.5H:1 V and fill slopes will be graded to 211:1 V or less, with all
disturbed slopes to be stabilized by seeding with the topsoil stockpile stabilization seed mixture. For permitting
purposes, a road disturbance corridor 100 feet wide has been defined as encompassing all project - related activities,
including road construction and topsoil stockpiling/windrowing.
Preparation of the ventilation shaft pad will involve topsoil recovery and stockpiling, installation of required
drainage structures, grading and compaction to establish a level pad working area, excavation of a collection pit for
blind drilling of the shaft pilot hole and shaft, haulage or stockpiling of the excavated borrow material, and
placement of gravel surfacing material to control dust and sediment from the pad area. Excavated borrow material
from the collection pit will be hauled to the nearby Fish Creek Loadout for use in final reclamation. The collection
pit will be approximately 100 x 200 x 10 feet and is sized to contain all drilling fluids and cuttings. In the event
unanticipated ground water flows are encountered, they would occur during drilling of the pilot hole when the
collection pit would have significant excess capacity. The combination of excess capacity and flow controls should
be adequate to prevent any off -site discharge. Facility construction details and configuration are illustrated by
Maps 1 S -50 and 1 W -50 in Exhibits 16C and 16D. The cuttings pit and associated foundation area will be inspected
during topsoil stripping, placement of the liner, and temporary closure, on completion of shaft boring operations.
As -built certification will be provided to the CDMG prior to cuttings placement and following temporary closure.
Primary Method of Construction — Blind Drilling _Prior to the beginning of the blind drilling process, a pressurized
pre -grout operation utilizing up to ten small diameter (2 ") holes, up to approximately 400 feet deep around the shaft
perimeter will be considered and undertaken, as needed, to limit groundwater flows between the shaft and the
formations. Individual grout holes would be drilled and a cement grout would be pumped under pressure into each
borehole before completing the next hole, to seal any wet zones encountered. Each borehole would be filled with
grout and allowed to set -up, effectively sealing the borehole and any fractures or voids in the grouted formation(s).
Any surface casing extending above ground surface will be cut -off flush with or below natural ground level.
If needed and once the pre -grout operation is completed, a shaft collar will be excavated to an approximate 10 -foot
diameter to competent rock at a depth of approximately 10 -15 feet. Material from the collar excavation will be
placed within and on one end of the cuttings pit. A surface casing approximately 8 feet in diameter (inside) and
large enough to accept the shaft casing and drilling tools will be installed in the shaft collar. This surface casing
will be either steel casing grouted in -place or cast -in -place concrete. A 48 by 24 foot concrete T- shaped pad will
then be poured to accommodate the drilling and casing equipment. Specialized blind drilling equipment in the form
of an A -leg derrick will be used to drill the pilot hole and excavate the shaft.
A nominal 17 -1/2 -inch pilot hole will then be drilled to an approximate depth of 1,000 feet and surveyed to
determine vertical shaft deviation and location underground for mine entry tie -ins. The pilot hole will then be
reamed to a nominal diameter of 7.5 feet to accommodate the final steel liner. The reaming technique utilizes an
inverted disc cutter equipped hemispherical raise bore head to cut the rock. During the drilling of the pilot hole and
the 7.5' diameter excavation, all cuttings will be removed from the excavation using an airlift system, with water
(reverse circulation) being the circulation media. Supplemental water, for drilling and to adjust the density of the
drilling medium, may be supplied, as needed, by a small portable pump drawing from Fish Creek under TCC's
existing water rights. The cuttings will be placed in a 200 x 100 x 10 foot, lined temporary mine development
waste pit excavated within the shaft pad adjacent to the shaft excavation, as shown on Map 1W. The cuttings pit
will be lined with a nominal 30 -mil PVC flexible membrane liner having a permeability of _10 -12 cm/sec.
TR09 -66 2.05-45.5 02/17/09