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Mud pits will be constructed within the graded pad area. Generally two or three pits are required, with typical pit
<br />dimensions of 10 x 10 feet and 5 feet deep. The size of the required pits is dependent on the anticipated drilling
<br />depths and conditions. Materials excavated from the pits will be stockpiled on the margins of the pad area for
<br />futwe use in backfilling the pits. All drilling fluids will be contained within the mud pits, and all drilling supplies
<br />will be contained within the azea of the drill pad. )£ twinning of any drilihole becomes necessary, it is anticipated
<br />that the additional drilling would occur within the limits of the previously constructed drill-pad. Any runoff and
<br />associated suspended sediment from the drill pad will be controlled and contained by a perimeter berm on the
<br />downgradient side(s) of the drill-pad. _ _ _
<br />Drillin~Operations -One or more rotary drill-rigs, capable of rotary drilling and spot-coring, will be utilized for
<br />general exploration work. The drill-rig will be attack-mounted, rubber-tired unit, capable of operating in rough
<br />terrain. Support equipment for the drill-rig will include, but not be limited, to a water truck, pipe truck and/or pipe
<br />trailer, rig-up truck, air compressor, core trailer, and two or more 4 x 4 pickups for drill-crews and company
<br />representatives. For each drillhole, a short section (typically 40-60 feet) of threaded surface casing will be set to
<br />stabilize unconsolidated surface materials. Drillholes will be a nominal 6.25 inches in diameter and will vary in
<br />depth from 1,000 to 1,800 feet. The location and anticipated total depth for each drillhole aze identified in Table 1.
<br />It is anticipated that one or more of the Lower Coal Group coal seams (D through F seams) and associated roof and
<br />floor units will be cored in each drillhole. If other coal seams of interest aze penetrated they maybe cored, as well.
<br />Cores will be recovered, examined and logged by a qualified geologist, and core samples may be sent-off for
<br />analysis of coal and roof/floor chemistry and characteristics and rock-strength parameters. it is anticipated that
<br />none of the coreholes will extend into the Trout Creek Sandstone. The primary circulation medium will be water
<br />and drilling mud. In the event that subswface conditions aze favorable, air or an air/foam medium maybe utilized,
<br />as an alternative to mud. Water for drilling will be obtained from stockponds located on fee surface controlled by
<br />BTU-EC' BTU-EC will specify in any drilling contract that only non-toxic, bio-degradable compounds and
<br />additives may be used for drilling.
<br />Geonhvsical Logging - On completion of drilling and core recovery, geophysical logging will be completed for
<br />each drillhole to obtain additional geologic information. Atruck-mounted geophysical logging unit will be used to
<br />obtain, correlate, and store logging information which may include density, gamma, caliper, neutron, focused
<br />electric, sonic, verticality, temperature, and conductivity. BTU-EC will retain in its files all drill and geophysical
<br />logs for at least one yeaz, and will make them available for inspection by an authorized officer.
<br />Exnloration Maintenance Activities -Other than initial road maintenance to establish good access, it is anticipated
<br />that access road maintenance requirements will be minimal, since the majority of the exploration efforts will ocew
<br />during the dry summer months, or when the Bound is frozen. Other maintenance requirements will include general
<br />housekeeping in active exploration areas and regular inspection and maintenance (as necessary) of drainage
<br />structwes.
<br />Monitorine or Water-Supply Well Completion -Dependent on location, depth, and groundwater conditions
<br />encountered, selected exploration drillholes may be converted to hydrologic monitoring or water-supply wells. In
<br />compliance with applicable provisions of 43CFR 3484.1{a), prior to conversion of an exploration drillhole to a
<br />monitor well, authorization will be obtained from the jurisdictional regulatory authority(s). Given typical timing
<br />for exploration activities, if BTU-EC determines that it would be beneficial to convert an exploration drillhole to a
<br />monitoring or water-supply well, both the CDMG and Division of Water Resowces will be immediately contacted
<br />and provided with relevant drilling information and a justification for the well. BTU-EC would then obtain
<br />preliminary concurrence prior to proceeding with well completion. Wells completion would involve casing the
<br />open drillhole, placing 20-slot screen and 8/12 silica sand or apre-packed, stainless steel or PVC well screen in the
<br />desired completion interval, establishing bentonitic plugs above and below the screened interval and grouting the
<br />well annulus to prohibit vertical migration and cross-contamination of aquifers, and developing the well by
<br />successively flushing and pumping the well bore. Figure 2, Typical Monitoring Well Completion, illustrates
<br />typical completion methods.
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