PERMFILE130951

• Permit No: C1981022A
• IBM Index Class Name: Permit File
• Doc Date: 9/16/2005
• Section_Exhibit Name: 2.04 Environmental Resources
• Media Type: D
• Archive: Yes

• 1997 West Valley Fill Soil Survey - In preparation for permitting of the West Valley Fill, soils on the
lower ridgelines, drainage sideslopes, and at the outlets of small ephemeral drainages between Elk and
Beaz Creeks were examined and sampled. Generally, the soils on the lower ddgelines and drainage
sideslopes were Ton-iorthent-Rock outcrop, sandstone complex grading to Torriorthent-Haplazgids
complex. The only additional soil unit identified was a Haplargid soil associated with small alluvia]
fans at the outlets of the ephemeral drainages.in the sampling area.
1999 Elk Creek Mine Facilities Area Sampling - In conjunction with permitting of the Ells Creek
Mine surface facilities, three soil samples were obtained in the proposed mine disturbance azeas and
analyzed or tested for chemical and/or physical characteristics. One bulk grab sample (SSO} was
obtained at the base of an existing natural slide in order to evaluate the physical properties of slide
materials for use in construction of the Elk Creek Mine portal benches and associated roads. A
consolidated un-drained compression test was performed on the sample with results as outlined in
Exhibit 2.05-E2, Geotechnical Design and Stability Analyses. The other two soil samples were
collected at the upper (S02) and lower (SOl) ends of the planned mine disturbance azea in the
vicinities of the upper and lower mine portal benches. Soil horizons and depths were logged during
sample collection and samples were analyzed for basic soil suitability pazameters. Soils were primarily
sandy clay loans and clay loans and depths ranged from 4 to 24 inches before heavy clays or high
rock content soils were encountered that would limit soil suitability.
2003 II West Coal Refuse Facility Soils Survey - In preparation for permitting bf the II West Coal
Refuse Facility, soils within azeas potentially affected by facility constmcdon and development were
examined and sampled by)ames Nyenhuis, Professional Soil Scientist, The proposed coal refuse fill
area lies within a minor ephemeral drainage west of the Mine Facilities Area. Soils within the
footprint of the coal refuse fill azea and along the western portion of the associated road corridors aze
• Torriorthents-Rock outcrop, sandstone, complex, with inclusions of Fluvent soils at the lower limits
of the drainage in the azea of proposed sedimentation pond. These aze deep, well-drained soils which
aze suitable for recovery and use as a revegetation medium, except along the western portions of the
road corridors where steep slopes, high rock content, and shallow depth to bedrock would limit both
soil suitability and feasibility of soil recovery. Recovery depth will vary with terrain, but is projected at
the lesser of 48 inches or depth to bedrock. Five soil samples were recovered and analyzed within tlils
soil type. Soils in the remainder of the project area, along the eastern portion of the road comdoxs,
were identified and mapped as Torriorthents- Haplazgids. One soil sample was collected and analyzed
for this soil type. Soil recovery depth is projected to average approximately 12 inches.
Mapping Unit Descriptions -The following are mapping unit descriptions from the USDA-SCS
soil survey report for the mapping units identified by site-specific soils evaluations and shown on the
Regional Soils Map, (Map 2.04-M4):
Absazokee-Work loam -This soil is a moderately deep, well-drained. soil formed from weathered
sandstone and reworked eolian materials. The soil is positioned on the steeper slopes, small ridges on
the uplands and valley sideslopes. The Absazokee soil makes up about 40 percent of this complex and
is on the steeper sideslopes and on small ridges. The Work soil makes up about 40 percent and is in
depressions and swales. ]nduded in this complex aze small areas of other soil types making up
approximately 20 percent of the complex. For the Absarokee soils, the surface layer is a loam that
varies from 0 - 7 inches thick with a clay subsoil approximately 18 inches thick. The substrate is
channery clay loam over sandstone at a depth of about 30 inches. For the Work soils, the surface
layer is a loam approximately 6 inches thick with a clay subsoil approxunately 33 inches thick. The
substrate is a channery loam extending to a depth of 60 inches or more.
• PermeabiIities for the surface and subsurface are moderate (0.G=2.0"/hr.) and slow co very slow (0.2-
i
0.6"/hr.), respectively and available water capacities for the Absarokee and Work soils aze ]ow and
high, respectively, Surface runoff is medium and erosion hazard is slight from wind and moderate to
.high from water. These soils typically support native vegetation consisting mainly of Gambel oak,
serviceberry, big sagebrush, wheatgrasses, and bromes. Associated uses include livestock grazing,
lIWCRF 2.04-88 Revised )une 2003