2009-02-10_PERMIT FILE - C1981022 ‎(5)‎

• Permit No: C1981022
• IBM Index Class Name: Permit File
• Doc Date: 2/10/2009
• Section_Exhibit Name: 2.04 Environmental Resources
• Media Type: D
• Archive: No

Seaion - 2.04.6
U.S. Steel Mining Company B and C Seam Sampling/Analysis - In January 1981, U.S. Steel Muting
• Company completed geochemical analyses of drillhole core samples from drillhole WSC a 4. The
core samples analyzed included composite samples of roof and floor materials from the B and C coal
in U.S. Steel's Somerset Mme.
Bear Coal Company B Seam Sampling/Analysis - In June 1989, Bear Coal Company collected and
completed geochemical analyses of a roof and floor sample from the B coal seam in the Bear No. 3
Mme and coal mining waste samples from two temporary mining waste stockpiles.
Somerset Mining Company B and C Seam Sampling/Analysis - In November 1990, the Somerset
Mining Company completed drilling of two exploration drillholes, drillholes SG 1 and SC-2, through
the C coal seam and into the B seam Composite samples of roof, floor, and coal seam materials were
analyzed for the C seam for both drillholes. Given plans to develop decline ramps from the C seam
to access the B seam, composite sample analyses for the C seam floor materials included the
interburden between the B and C coal seams. Since existing analyses information was available for B
seam roof and floor materials, geochemical analysis for the B seam was limited to coal seam materials.
Oxbow Mining, Inc. D Seam Sampling/Analysis - In August 1998, Oxbow Mining, Inc. completed
geochemical analyses of drillhole core samples from drillholes EC-5, EC-6, and EC-10. The core
samples analyzed included composite samples of roof and floor materials from the D seam for
Oxbow Muting, Inc.'s proposed Elk Creek Mine
Analysis results for potential coal refuse materials have been compared with established suitability
criteria for revegetation media as outlined by the Wyoming Department of Environmental Quality
Guideline No. 1 (WDEQ, November 1984) and the Montana Department of State Lands Guidelines.
Table 2.04.6-T1, Summary - Roof, Floor, Interburden, and Coal Materials Suitability Evaluation,
• presents analysis results and identifies any parameters (shaded) which represent a potential concern.
Roof and Floor Materials - Characteristics - The following summarizes suitability criteria,
suitability characteristics, and acid- or toxic-producing potential by parameter for the materials
sampled based on analysis results. Full analysis results for all material samples are included in Exhibit
2.04 - E3, Geologic Information:
pH - Paste pH is used as a measure of the relative potential for a material to generate acidity after
short-term exposure to meteoric water (precipitation) and as a measure of the relative intensity of
acid or basic conditions. In addition, the solubility of a number of chemical parameters is dependent
on pH. A suitability criteria of 5.0 >pH<9.0 was used to evaluate the existing data. The pH values
for the 52 samples analyzed ranged from 6.8 to 9.5 with a mean of 8.8, indicating neutral to slightly
alkaline materials. Some of the samples slightly exceeded the upper limit of the suitability criteria (i.e.
pH >9.0). However, paste pH is only indicative of the short-term acidity of a sample and is strongly
influenced by the presence of soluble salts. Subsequent flushing of the material by precipitation
should result in long-tern pH values of less than 9.0.
/Electrical Conductivity (EC) - Electrical conductivity is used as a general indicator of water quality and
soil salinity and is directly proportional to total dissolved solids (TDS) concentration and salinity. A
suitability threshold of 8,000 µmhos/cm was used to evaluate electrical conductivity data. Electrical
conductivity values ranged from 200 to 2,840 pmhos/cm with a mean of 1,168 pmhos/cm These
data indicate that no problems are expected with respect to salinity as indicated by EC values.
-/Acid-Base Potential (AB) - The acid-base potential is used to evaluate the long-term potential of coal
mining waste materials to generate acid drainage. Results from acid-base potential testing are used to
compare the acid neutralization potential of a material with its acid generation capability. A suitability
criteria of greater than -5 tons of CaCO3 per 1,000 tons of material was used to evaluate AB values.
PR04 2.04-13 Revised August 2000