PERMFILE132276

• Permit No: X200520510
• IBM Index Class Name: Permit File
• Doc Date: 5/31/2005
• Doc Name: NOI Application
• From: Twentymile Coal Company
• To: DMG
• Media Type: D
• Archive: No

Drilling Methods and Equipment: Exploration holes will be established with grubber-tired tnick-mounted
air/foam rotary drill. Drilling mud maybe employed in the drilling medium. Previous drilling activities in
the immediate area have not encountered water-bearing formations producing any appreciable quantities of
water from the strata overlying the coal seam of interest. Both the Twentymile Sandstone and Wadge
Overburden have been documented to contain water; however, neither typically exhibits sufficient head to
produce flows at the surface. Drillhole depths projected for each site are specified on 2005 NOI Table 1.
After drilling, the holes will be logged with a standard suite of geophysical data logging instruments. No
holes will be developed as water wells.
In reference to the drillholes, surface casing will be set to assure that drilling fluids are not lost in the
surficial soils. The surface casing will be grouted in place and then the hole will be advanced using
conventional air-foam drilling methods. Surface casing will have a threaded surface collar to allow for quick
shut-in of the hole, using a threaded shut-off valve, in case significant flows aze encountered.
The coal will be cored and the drillholes geophysically logged. On completion of the coring and logging, the
drillholes will be tremie-grouted through and twenty feet above the Wadge Overburden. From that point up,
the holes will either be grouted or backfilled with cuttings to within ten feet of the surface. The interval from
ten feet to within three feet of the surface will be grouted, and the remaining three feet will be backfilled with
soils. The surface casing will be cut off three feet below the surface or it may be removed entirely. The
drillholes will be surveyed to establish site coordinates to permanently locate the drillholes.
Reclamation Plan: Reclamation activities will begin once mud pits are sufficiently dry to allow regrading
of each site to occur. Mud pits will generally be filled or partially filled with drillhole cuttings. Materials
excavated for the mud pits will be backfilled into the pits and/or redistributed over the site, stockpiled topsoil
will be spread, and broadcast seeding will occur over the entire disturbed area using the following approved
seed mixture from Permit No. C-82-056. Newly constructed segments of access road will be reclaimed in a
similaz fashion, with stockpiled topsoil spread, and disturbed areas broadcast seeded.
Species
Slender Wheatgrass
Intermediate Wheatgrass
Pubescent Wheatgrass
Desert Wheatgrass
Orchardgrass
Timothy
Regar Meadow Brome
Lincoln Smooth Brome
Alfalfa
Cicer Milkvetch
Total
Seeding Rate (PLS Ibs/acre)
2.0
2.0
2.0
1.5
0.5
0.5
0.5
1.0
0.25
0.25
10.5
Seismic Lines: TCC is planning to conduct a limited seismic investigation. This program will use the
classic approach of drilling holes, setting-off small charges, and placement of geophones and instruments for
recording the data.
The seismic crew will establish five lines (WM_SM_07 through 11) approximately 7 miles in total length.
The attached maps illustrate seismic line locations and orientation. The lines vary in length, ranging from
0.9 to 2.5 miles in length. Shot-holes will be established on 125-foot centers. The geophones may extend up
to approximately 1,350 feet past the ends of the shot-lines.
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