Laserfiche WebLink
• sulfur. Pyritic sulfur values were utilized to calculate AP and ABP whenever sulfur fractionation <br />analyses were available. <br />Mean chemical values for seven additional parameters are listed in Table 2.04.6-9. No marginally <br />suitable or unsuitable values were determined for copper, lead, arsenic, zinc, nickel, cadmium, or <br />mercury. In a few instances, copper and zinc concentrations dropped below the plant deficiency <br />level. However, ample concentrations are present in the topsoil and subsoil. Since the <br />aforementioned parameters (Cu, Pb, As, Zn, Ni, Cd, and Hg) were all at nontoxic levels for Site <br />870E, they were not determined on samples collected from the remaining Phase I or Phase I I sites. <br />Mean physicochemical values for each parameter are summarized in Table 2.04.6-10 for the entire <br />New Horizon 2 study area. All mean values fall within the suitable and marginally suitable ranges <br />as outlined by the assessment criteria listed in Table 2.04.6-3. Overall, about 83 percent of all <br />overburden and interburden strata has suitable physical and chemical characteristics. <br />Sulfur fractionation analyses indicate pyrite comprises only 10 percent of the total sulfur in the <br />overburden but 45 to 85 percent in Units 2, 3, 4, and 6. Contrastingly, sulfate comprises 70 percent <br />• of the total sulfur in the overburden but only 5 to 25 percent in Units 2, 3, 4, and 6. Organic sulfur <br />typically comprises between 15 and 30 percent of the total sulfur for all lithologic units. <br />Texture and saturation percentage occasionally exceeded suitability levels in the overburden and <br />underburdenmaterial(PeabodyAppendix6-5). Theunderburdenpredominantlyconsistsofavery <br />hard, indurated sandstone which typically has a sand texture and low (less than 25 percent) <br />saturation percentage. These strata will not be disturbed by mining. Two lenses of white silty shale <br />and soft brownish gray shale occur in the overburden. This strata occurs in the western half of the <br />study area (Sites 870E, 872E, 881 E, and 882E) and outcrops slightly east of Site 870E. The soft <br />weathered shale strata typically has a clay texture and high (greater than 85 percent) saturation <br />percentage. Since these strata occur in thin lenses and comprise only about five percent of the <br />overburden volume, normal overburden handling by dozers and scrapers will effectively blend or <br />dilute the unsuitable clay levels to acceptable levels. <br />Mitigative Measures for Marginally Suitable to Unsuitable Material <br />• Revised 27 Aug 2002 34 <br />