2010-05-07_PERMIT FILE - C2009087 (14)

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• between the south end of the Seneca II Mine permit area and the north end of the Foidel Creek Mine permit area. Concerning the additional soils mapping, initial mapping units were identified using soil legends from both the Seneca II Mine (Seneca Coal Company, 1997) and Foidel Creek Mine (Twentymile Coal Company, 1999) baseline soil surveys, as well as the Natural Resources Conservation Service (NRCS) soils legend for Routt County (NRCS, 2008). The entire area was traversed by vehicle on dirt two- tracks where possible, and then elsewhere on foot. Soil map unit boundaries were delineated by observing surface conditions, vegetation, slope gradient and aspect, geology, and most importantly soil profiles exposed using a sharpshooter spade and bucket auger. All major soils mapped in these two potential surface - affected areas were fully described and sampled at representative sites a minimum of one time each. Based on experience with previous underground coal mine projects, this sampling intensity is sufficient and consistent with previous recommendations for proposed affected -area disturbances on other projects in Colorado and other western states. The amount of additional soil sampling, beyond the minimum, is left to the professional judgement of the certified soil scientist. For the approximate 240 acres of potential surface disturbance, a total of six representative soil sites were sampled by major horizons and subhorizons for laboratory characterization. The location of all soil sample sites is shown on the soil maps. • A total of thirty soil samples were collected from the six sample sites. Based on discussion between Jim Nyenhuis and Ms. Sandy Brown (CDRMS), the current amount of soil sampling was sufficient for the Sage Creek Mine project (Brown, 2008). The soil samples were delivered to Colorado State University's Soil Testing Laboratory in Fort Collins, Colorado, for standard soils analysis (CSU, 1988, as revised). The soils laboratory analysis included the following parameters: pH; saturation percent; electrical conductivity (EC); calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K) (meq /L); calculation of sodium adsorption ratio (SAR); organic matter percent (Walkley- Black method); nitrate - nitrogen (NO3 -N), lime estimate, soil texture (percent sand, silt, and clay), and micronutrients (ppm by AB -DTPA method) phosphorus (P), potassium (K), zinc (Zn), iron (Fe), manganese (Mn), and copper (Cu). Laboratory analysis of Selenium and Boron (mg /kg, ppm) was not necessary for this project. The results of the laboratory analysis were reported on October 30, 2008, and are included with this report. A 10% duplicate analysis was conducted for quality assurance /quality control (QA/QC) purposes, and the results are on file at CSU. 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 were 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; coarse fragment content >35 %; saturation percent <25% or >80% (marginal rated); and sand, • 3