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0 <br />In the east portion of the permit area, high ESP values are present at various locations in the overburden <br />profile. The high ESP values are associated with high clay contents in overburden material. High ESP <br />values are not expected to be a problem in these spoils as mining will not generally occur in lower strata <br />having higher sodium values. However, where high sodium values are present in strippable overburden, <br />good conditions exist for mixing these overburden layers. For example, those layers having poor chemical <br />and physical properties are mixed during the normal regrade process with adjacent or nearby layers that <br />have good chemical and physical properties. Topsoil placement over these mixed spoil layers will ensure <br />adequate soil composition to promote plant growth and successful reclamation. Spoil sampling and <br />analysis of regraded spoils from 1985-1987 (Appendix I Section 4) showed no indication of high ESP <br />values in any reclaimed area. <br />In the west portion of the permit area, additional overburden analysis has not been conducted since the <br />initial Stearns -Roger study. High ESP values have been of little concern in this area and Trapper does not <br />expect problematic ESP values in the proposed mining area based on the results of routine regraded spoil <br />sampling and analysis conducted on the mine through 2000. <br />• In the Stearns -Roger analysis, samples of cuttings were composited from 30 feet of overburden directly <br />above the lowest mineable coal seam from multiple seam areas and from the parting interval between <br />seams. <br />The twelve core holes are depicted on two East-West cross-sections (Map M37). The even numbered <br />holes comprise the northern section and the odd numbered holes comprise the southern section of the <br />proposed permit area. For ease of interpretation, the strata depicted on the two cross sections are divided <br />into the following six groups. <br />1) topsoil layer <br />2) coal layer(s) <br />3) sandstone layer(s) <br />4) shale-siltstone layer(s) <br />5) sand layer(s) <br />6) clay layer(s). <br />2-361 <br />Revision; rF-Bi <br />Approved; / O <br />