2012-01-06_PERMIT FILE - C1982057 ‎(18)‎

• Permit No: C1982057
• IBM Index Class Name: Permit File
• Doc Date: 1/6/2012
• Section_Exhibit Name: Tab 06 Geology and Overburden Assessment
• Media Type: D
• Archive: No

Sage Creek Overburden (SCOV) interval - 200-250 feet bgs;
Upper Wolf Creek Overburden (UWCOV) interval - 250-310 feet bgs;
Lower Wolf Creek Overburden ILWCOV) interval - 310-360 feet bgs; and
Wolf Creek Underburden IWI:UB) interval - 360-410 feet bgs.
Based on the mining sequence using dragline to uncover the Wolf Creek seam and scrapers to uncover
the Sage Creek seam, the upper Wolf Creek overburden will be at the bottom of the spoil sequence
while the lower Wolf Creek overburden will be at the top of the sequence and can be ultimately
covered with Sage Creek overburden.
The analytical results are summarized in this section for the four intervals. Tables 6-7A through 6-7D
present the maximum, minimum and average for each analyte tested over each interval for the
composited samples. The Sage Creek Overburden samples (SCOV) are equivalent to the Wadge Coal
Underburden as presented in the original permit. The assessment for WCOV from WWCU-24 included
50 feet of material while the original permit assessed only the material down to 10 feet below the
Wadge coal. The characteristics of the Wadge Underburden were included in the original permit.
The analytical data for the four intervals are consistent and are typical for the Williams Fork Formation.
The SCOV material was slightly more conductive, higher acid-base potential (ABP) and more iron and
manganese on average than the other intervals. Generally it had less clay, lower saturation percent and
less boron and fluoride than the other intervals. Generally, clay, saturation percent and boron increased
with depth while ABP and iron decreased. The LWCOV interval had the only value averaged across the
interval that would be considered unsuitable. The analyte was lead. Note that there was only one of
the five samples that would be considered unsuitable individually and this value was high enough to
bring the average value for the interval into the unsuitable range. The only other analyte Yhat had the
highest average value in the LWCOV interval was mercury. Lead and nickel were marginally suitable in
all four intervals (except as described above) and boron was marginally suitable in SCOV, UWCOV and
LWCOV. UWCOV had one sample that individually would be considered unsuitable for lead but it did
not increase the average value into the unsuitable range for the interval. The average iron values for
the SCOV, UWCOV and LWCOV intervals were deemed suitable. However, two of the five samples in
each interval would individually be considered unsuitable. The suitability results are presented in
appendix 6-5.
In the Yoast mine suitability assessment, the Wadge and Wolf Creek overburdens were described as
very similar and consistent with the Seneca and Seneca IIW mines although distinct physiochemical
differences were reported especially for certain parameters. For the Sage Creek overburden at II-W,
which is equivalent to the Wadge underburden in the Yoast permit, there were no major or minor
concerns noted in the assessment. Also fn the Yoast area, a major concern identified for the Wolf
creek overburden was potential acidity particularly 20-35 feet above the coal. This condition was not
duplicated in the Sage Creek/Wolf Creek mining area assessment.
PR03 27 Revised 01/02