2014-05-07_PERMIT FILE - C1996083 (2)

Home Browse Search

Volume III, Tab 7 provided by Cedar Creek Associates). The USGS 7.5 minute Bowie topographic quadrangle map of the study area, as well as the NRCS air-photo base Order 3 soils map of the study area were also utilized in the soils field work. The results of the soils field mapping, profile descriptions, and laboratory analysis were used to evaluate topsoil suitability and generate soil salvage recommendations. Unsuitability threshold values are taken from the Wyoming guideline and include: pH <5.0 or > 9.0, EC >12; SAR >15, or SAR >12 for soils with greater than 40% clay; Boron >5.0 ppm; coarse fragment content >35%; saturation percent <25% or >80% (marginal rated); Selenium >0.8 ppm (marginal rated); and sand, clay, or silty clay texture (marginal rated) (WDEQ, 1996). The recommended salvage depths are discussed in the map unit descriptions in the following results section. Topsoil and subsoil volumes for salvaged soils are included in the project mine and reclamation plan. 2.0 RESULTS The Gob Pile study area is adjacent to and west of the main Bowie NO. 2 area that was soil surveyed in 1995. The Gob Pile study area is located on a dominantly steep, south- southeast facing colluvial slope that emanates from the base of anortheast-southwest trending sandstone outcrop ledge. The rock outcrop is the "Rollins Sandstone Member" (geologic symbol Kmvr) which geologically is part of the Upper Cretaceous sedimentary "Mesa Verde Group or Formation", geologic symbol Kmv, (Dunrud, 1989; and Ellis, Gaskill and Dunrud, 1987). Most of the colluvial slope consists of unconsolidated surFcial Pleistocene deposits (geologic symbol Quwe). There also is a small area of Upper Cretaceous Mancos Shale, geologic symbol Km, on the colluvial slope. Elevations within the study area range from about 7,060 feet in the northwest corner to about 6,010 feet MSL in the southeast corner. The study area is currently used as rangeland, wildlife habitat, recreation, and undeveloped land. The Bowie No. 2 Mine Gob Pile Soils Map is attached to this report. It was complied on a recent (May 26, 2005) color photobase map at an approximate scale of 1:6600 (1 "= 550 feet). The boundary line for the soils study area is included on the map as well as all soil map unit delineation lines and all plotted and numbered soil sample sites. The Gob Pile study area is characterized by the presence of five soil map units (Map Units 1, 2, 4, 5, and 6). These map units were initially set up during the original soil survey of the Bowie No. 2 Mine in 1995 (Champion, 1995). Because the soils associated with these map units on the Gob Pile area are similar, with some changes, to those on the adjacent Bowie mine area, the original map unit numbers are used in the Gob Pile survey. The soil names have been slightly changed to be consistent with the Gob Pile study area. • 3 Exhibit 7 - 2007 Soil Survey Report