Laserfiche WebLink
State Reg. <br />• Compactibility, Erodibility, and Coal Quality <br />Determining the compaction potential of disturbed overburden is <br />important to access postmine spoil conditions including: hydraulic <br />conductivity, revegetation success, landscape stability, and equipment <br />trafficability. Generally, stability and/or compaction problems are <br />related to soils high in shrink/swell clays, soils with large proportions of <br />sand and clay (sandy clay texture), and soils with approximately equal <br />proportions of the sand, silt, and clay size particle fractions (Arnold, <br />1977). These three conditions are not highly desirable since a high <br />shrink/swell clay content in postmine landscapes causes poor stability <br />and low conductivity conditions; a sandy clay textured soil developer <br />surface crusting problems, and an equal particle size distribution causes <br />excessive compaction which results in restricted water movement and <br />root growth. <br />• The first two considerations listed above were among those used for <br />establishing the grading system for texture. Spoils grading poor in <br />texture are discussed within the Overburden Mixing and Mitigation of <br />Inhibitory Material Section and in Table 6-7. The four overburden <br />increments that were identified as having clay contents greater than <br />40 percent (poor suitability rating, see Table 6-3) will be blended and <br />diluted to acceptable levels during normal spoiling operations. The third <br />condition listed above does not exist at Seneca since the mean particle <br />size analysis shows a percentage breakdown of 39 percent sand, 44 <br />percent silt, and 17 percent clay (see Table 6-6). <br />Spoil erodibility is anticipated to be negligible over the life of mine since <br />graded spoil piles will be topsoiled. Thus, the emphasis on erodibility <br />potential is found in the Soils Section (Exhibit 9) rather than in the <br />Overburden Section. <br />Table 6-8, Coal Seam Analysis, summarizes the quality of the Wadge, <br />• Wolf Creek, and Lennox coal seams for Seneca Mine. Specific analysis <br />for the mineral marcasite was not performed on any of the samples listed <br />in Table 6-13. However, marcasite content will be included as part of the <br />total sulfur (pyritic) content and is therefore unnecessary. <br />6-31 <br />