2008-03-12_REPORT - C1980005 - Laserfiche WebLink

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2.0 METHODS Each area to be sampled was delineated on a recent Seneca Coal photobase map. All sample locations were randomly selected and geographically distributed across each area. Soil backhoe pits were located and dug to at least five feet by Seneca Coal. A composite sample of each appropriate depth interval was collected at each pit location. Samples were screened in the field over a No.10 (2mm) screen to remove the much larger, hard rocks, and the percent coarse fragments (gravel, cobble, and boulder size rock material) was estimated and recorded on the profile description form. Sample depth was noted for each location as well as other pertinent information. In addition to soil sampling, a complete soil profile description was completed at each backhoe pit location. Soils description followed standard Natural Resources Conservation Service (NRCS) field methods (Schoeneberger et.al., 2002). Digital photographs were taken of each pit and adjacent landscape. All soil and spoil laboratory data was reviewed and approved by IML soils laboratory supervisor Ms. Karen Secor. All soil and spoil samples were analyzed by IML. The analytical parameters for the soil backhoe pits included: pH; saturation percent, electrical conductivity (EC); sodium adsorption ratio (SAR calculation from meq/L for calcium, magnesium, and sodium); texture (percent sand, silt, and clay - by hydrometer method), and NPK (nitrate-nitrogen, phosphorus, and potassium, ppm). The overburden spoil samples from the backhoe pits were also analyzed for these parameters, except for phosphorus and potassium, as well as Boron (B), Selenium (Se), and acid-base potential (ABP) which included separate analysis/calculation for total sulfur percent, total sulfur acid-base (tons/1000 tons), neutralization potential (tons/1000 tons), and total sulfur acid-base potential (tons/1000 tons). None of the spoil samples needed the additional pyritic sulfur acid-base potential (tons/1000 tons) analysis (sulfur fractionation) which is routinely run for any samples with a total sulfur ABP of less than minus five (<5.0). All field and laboratory data were evaluated for "suitability" based on standard threshold values for significant parameters, primarily EC, SAR, and AB potential. References for suitability evaluation include "Criteria for Evaluating Overburden, Underburden, and Regraded Spoil Suitability" (Seneca Coal IIW Mine, Table 6-3, revised January 2002), and "Criteria to Establish Suitability of Topsoil, or Topsoil Substitutes, and Overburden" (Wyoming Department of Environmental Quality, Tables I-2 and I-4, revised November1996). Unsuitable values include pH (<5 or >9), saturation percent (<25 or >85), electrical conductivity (EC>12), sodicity (SAR >18 or >22 depending on percent clay content), and nitrate-nitrogen (>60ppm). Clay, sandy clay, or silty clay texture with greater than 50 percent clay content is also considered unsuitable except with amelioration (Seneca Coal IIW Mine, 2002). 3.0 RESULTS • Reapplied Topsoil/Overburden Spoil (Backhoe Pits) Laboratory Results• l 2