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lateral varlebility across identical strete in the study area. There is vertical . <br />variebtllty among strete where certain distinct physlochemicel differences ere apparent <br />between the Lennox, Yadge, end VoLf Creek areas, especially for the parameters pH, <br />seturatfon percent, conductivity, sand content, clay content, boron, and acid-base <br />potential. As discussed in the Xining end Mitigation of Unsuitable Overburden section and <br />Teb 27, Minesoil Reconstruction, few of these parameters will impact overall spoil <br />suitability. In many instances, avoidance end typlcel overburden handling will <br />effectively blend, dilute, bury, and mitigate potentially inimical zones es documented in <br />Appendix 6-3. <br />The major or significant concern within the Yadge coal recovery portion of the Yoast study <br />area is the excessive clay levels found in the 60 feet of shale strata which overlies the <br />Lennox coal seem. Two less significant or minor concerns ere the potential acidity end <br />boron values associated with the Lennox coal seam and encapsulating strata. These strata <br />will be encountered primarily between the Lennox coal outcrop end final highwall in the <br />northwestern, central neck, end western portions of the mine where the overburden is <br />thicker than 60 feet (Exhibit 6-3). The major concern within the Yolf Creek coal recovery <br />portion of the Yoest study area is the potential acidity associated with the strata • <br />located 20 to 35 feet above the coal. This strata will be encountered in the southeastern <br />pert of the mine es shown on Exhibit 6-4. Typical overburden handling will bury much of <br />the clay, boron, and potentially acidic strata. Sampling plans will be used in the Yadge <br />.` <br />area where the overburden is thicker then 60 fee[ (as shown on Exhibit 6-4) end in the <br />entire Yolf Creek area to identify final graded areas having an unsuitable clay, boron, <br />pH, and/or acid base potential level. The unsuitable shale and clay strata encountered in <br />the reduced highwall or upper three feet of final graded spoil will be :scarified prior <br />to being covered with topsoil. Final graded areas having an unsuitable active or <br />potential acidity will be neutralized with amendments or covered with a minimum of four <br />feet of suitable root grouch medium including soil. The sampling plan and mitigative <br />measures are discussed in further detail in Teb 21. Minesoil Reconstruction.. <br />Literature Cited <br />American Society for Testing Materiels (ASTX ). 7980. Gaseous Fuels - Coal and Coke - <br />Atmospheric Analysis. Annual Book of ASTM Standards, Pert 26. <br />Donahue, R.L., R.Y. Miller, and J.C. Shickluna. 1977. Soils - An Introduction to Soils <br />end Plant Growth. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. 626 p. <br />34 Revised 03/07/95 <br />