2010-05-07_PERMIT FILE - C2009087 (8)

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RULE 2 - PERMITS • • Winevada - Splitro complex, three to 25 percent slopes • Bulkley silty clay, 12 to 25 percent slopes • Cryoborolls, cryorthents soils, rock outcrop, 25 to 99 percent slopes • Winevada fine sandy loam, 25 to 65 percent slopes • Impass (formerly Binco) silty clay loam, 12 to 25 percent slopes • Yampatika silty clay, 25 to 65 percent slopes • Phippsberg (formerly Aaberg) clay loam, 25 to 65 percent slopes • Bulkley silty clay, three to 12 percent slopes • Yampatika silty clay, 12 to 25 percent slopes • Dunckley- Skyway complex, 25 to 65 percent slopes Map 2.04.9 -M1, Soil Types, shows the locations and boundaries of the mapped soil units within the general PSCM permit area. Table 2.04.9 -T1, contains the acreages of each soil map unit within the PSCM permit area. Over 17 percent of the proposed PSCM permit area is mapped as the Winevada - Splitro Complex with slopes ranging from three to 25 percent. A soil complex consists of areas of two or more soils, so intricately mixed or so small in size that they cannot be shown separately on the soil map. Each area of a complex contains some of each of the two or more dominant soils, and the pattern and relative proportions are about the same in all areas. The Winevada series is a moderately deep soil formed in residuum and colluvium derived from sandstone. The soil has approximately 24 inches of fine sandy loam and loam textures over weathered sandstone bedrock. The Splitro series consists • of shallow soils over sandstone that is formed in alluvium, residuum, and eolian deposits. Approximately nine percent of the PSCM permit area is comprised of the Bulkley silty clay series which consists of a very deep soil formed from alluvium derived from shale. These soils can have B horizons at depths greater than five feet. However, borrow depths can be limited due to high percentages of clay size particles. Soils more prominently mapped near or in the proposed disturbance area include the Impass silty clay loam, Phippsberg clay loam, and a reclaimed area classified as Arrents ( Arents) to the suborder level only. Arents are poorly developed soils which have three percent or more (by volume) fragments of diagnostic horizons that are not arranged in any discernible order at depths between 25 and 100 centimeters. Site - Specific Soils Mapping and Characterization The Order I soil survey map of the PSCM disturbance area, conducted by Jim Nyenhuis, is presented on Map 2.04.9 -M2, Order I Soils Survey — Surface Disturbance Area. Based on the available Order I soil survey, the existing soils which have the potential to be disturbed by mining and related activities are limited to nine soil mapping units (approximately 391 acres). Two of these map units (approximately 232 acres) are reclaimed land and/or previously disturbed lands, one map unit is classified as rockland and one map unit is classified as open water. The majority of the remaining five map units consist of the Binco clay and the Aaberg silty clay. The Binco soil series has been renamed the Impass and the Aaberg soil series has been renamed the Phippsberg in this area due to changes in soil taxonomy and available weather data. • PSCM Permit App. 2.04 -120 Revision 12/17/09