2009-08-13_PERMIT FILE - C1981019A ‎(4)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 8/13/2009
• Section_Exhibit Name: Rule 2 Permits -ST
• Media Type: D
• Archive: Yes

RULE 2 PERMITS
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provided in the WDEQ guidelines. These samples aze all in interburden and almost exclusively beneath
the deeper coal seams (Exhibit 6, Item 6). Mining operations will naturally rebury these deeper
interburden layers in the lower portions of the pit. Of 308 regaded spoil piles in Colowyo Mine
operations reported in the 2005 Annual Reclamation Report, only eight exceeded the WDEQ SAR
"suitable" criterion of 10, only two exceeded the permit "suspect level" of 15, and the mean value was
2.01. As such, SAR is not expected to be an issue in the regaded spoil in the South Taylor pit.
Saturation percent was outside of the WDEQ "suitable" range in 477 feet, or 10.9% of the borehole
intervals. Mean saturation percent ranged from about 35 to 50%. During reclamation, overburden is
homogenized and the saturation percent of the various layers is averaged. As reported in the 2005 Annual
Reclamation Report, the 34 samples of regaded spoil analyzed for percent saturation ranged from 28 to
60.5% saturation, which is within the WDEQ "suitable" range. There are no WDEQ "unsuitable" criteria
for percent saturation.
The anticipated root and aquifer zones within the regaded overburden of South Taylor/L,ower Wilson
should be of suitable quality due to the following:
• There is a limited amount of unsuitable overburden material when compazed to the amount of
suitable overburden material within the South Taylor/Lower Wilson pit azeas.
• In general, the limited amount overburden material that is unsuitable will be mixed with suitable
material to create suitable root zone and aquifer restoration material during mining and the
backfilling of pits and out-of--pit disposal facilities.
• Unsuitable overburden materials that represent a considerable portion of the overburden to be
mined will be identified, selectively handled, and isolated from aquifer and root zone azeas within
• the backfilled pits and out-of--pit disposal facilities using the methods specified in the mine plan.
• Historic regaded spoil data from the existing operation demonstrates that current mining
practices consistently result in suitable overburden at this mining location.
• The approved overburden suitability criteria for the Colowyo Mine can be found in Volume 1,
Section 2.05 ofthe existing permit.

South Taylor/Lower Wilson -Rule 2, Page 36 Revision Date: 3/30/07
Revision No.: PR-02