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root structures to a depth of greater than 10 feet depth. A single discontinuous layer of broken angular <br />rock about six to twelve inches thick is present within much of the observed cut face. This is the only <br />competent rock in the bench 1 cut face. The bench 1 material overlies competent overburden, which <br />overlies the coal seams that are mined (see Photo 1). Bench 1 material is mechanically removed as a <br />separate unit and is the last overburden unit to be placed over the reclaimed mine. As such there are <br />generally several or more feet of the bench 1 material underlying replaced topsoil in the reclaimed <br />areas. <br />Part of the area of the mine south of BB Road and west of 2700 Road (reclassified as prime farmland) <br />and part of the area north of BB Road (non-prime farmland) have been mined and have had <br />overburden placed, but have not had topsoil replaced (Figure 1). The suitability of the Bench 1 subsoil <br />for use as the lower layer of prime farmland soil is the focus of this study. <br />Preliminary lit vestigation <br />On January 31, 2008, WFC personnel obtained six soil samples from the upper two feet of overburden <br />(samples 101 through 106, Figure 1). The soil was analyzed for texture, conductivity, pH, nitrogen, <br />organic matter, some anions and cations, calcium carbonate, moisture, and sodium adsorption ratio. A <br />summary of results relevant to prime farmland soil is presented in Table 1 and the lab data sheet is <br />attached to this letter. These samples were all within suitability criteria established in the permit and <br />by the NRCS for prime farmland subsoil for target analytes with the exception of one sample which <br />exceeded the electrical conductivity (soluble salts) suitability standard of 4.0 with a reading of 4.1 <br />micromhos/cm. <br />Second Investigation <br />After a meeting with the DRMS, NRCS, WFC, and other persomiel, WFC agreed to further analyze the <br />condition of the subsoil by examining the soil in pits placed on a 2.5-acre grid (330 feet per side). <br />These grid points were sequentially numbered across the portion of the mine that had been mined and <br />partially reclaimed. Of the 34 grid points, twenty were within areas that had been brought to grade <br />with overburden and were accessible (e.g. not covered with topsoil piles). These locations had soil pits <br />excavated, with 13 south of BB Road (in prime farmland) and seven north of BB Road (in non-prime <br />• farmland) (sample points numbered 1 through 34, Figure 1). All pits were excavated in areas that had <br />been brought to grade with overburden, but had not been prepared for topsoil placement or had topsoil <br />placed. WFC dug pits using a backhoe to a depth of three to four feet. Walsh personnel visited the site <br />on March 5, 2008 and described soil color, texture, percent coarse fraction (gravel, cobbles, stones, and <br />boulders), and hardness. Information was recorded into a field notebook and transferred to Table 2. <br />No boulders (>25 inches) were observed in any soil pit. <br />Soil samples were obtained from the upper two feet of the exposed soil. Samples from the prime <br />farmland area and select samples from the non-prime farmland area were sent to Servi-Tech <br />Laboratories of Hastings, Nebraska for pH, texture, calcium carbonate, and exchangeable sodium <br />percentage (ESP) and other analyses. Laboratory results are summarized in Table 2. Selected lab <br />analyses were based on discussions with David Dearstyne of the NRCS Montrose office. Mr. <br />Dearstyne stated in an email dated February 20, 2008 that soil deeper than 24 inches in prime farmland <br />should be tested for these parameters and compared to standards (shown on Table 2). If the soil is <br />within these criteria it would provide suitable subsoil (copy of email correspondence is attached). <br />;Ash <br />Environmental Scientists and Engineers, LLC <br />0 (Revised Nov 2008) Attachment 2.05.4(2)(d)-1-3