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did not exceed 25,000 cubic yards, only Rule 4.10.4(3) would apply. This rule requires the placement of <br />coal waste in 24 inch thick lifts and compaction of each lift to meet or exceed 90 percent of the <br />maximum dry density. A spontaneous combustion event within the waste pile was detected in 1985. <br />The hot material was removed, cooled and moved to the West Ridge disposal site. The final reclamation <br />for the old coal waste pile occurred in 1988. Quarterly waste bank inspections were terminated in 2005 <br />(TR -46) when the operator demonstrated the geotechnical and erosional stability of the waste pile. <br />The West Ridge coal mine waste bank was constructed in 1983 in accordance with Rules 4.01.1, 4.09.2, <br />4.10 and 4.11. In 1989, it was discovered that certain slopes had been constructed steeper than 2H:1 V <br />and insufficient compaction had been achieved at several locations. The repairs were approved in TR -71 <br />and accomplished in 1991. Rock drainages were installed in the drainages east and west of the northern <br />end of the bank in TR -25 in 1994. Final reclamation including seeding and mulching of the West Ridge <br />coal mine waste bank took place in 2008. The termination of quarterly inspections were proposed and <br />approved in TR -52 in 2010. <br />No ponds were requested for release in this application. <br />III. OBSERVATIONS AND FINDINGS <br />A) Backfill and Grading <br />The sealing and backfilling of the East Mine portals was approved in SL -2, April 9, 2004. The East <br />Mine benches were backfilled, graded and revegetated in 2008 and 2009. All highwalls of the bench <br />areas were removed. A series of four sandstone outcrops above the portal bench remain and are part of <br />the variance from AOC that was approved for the East Mine. These sandstone outcrops are delineated <br />map 6A -50. <br />The fills on each of the benches were reclaimed to an overall slope angle of 21-1: IV or 26.6 °, which is <br />designed to achieve a factor of safety in excess of 1.3 (Phase II Geotechnical Studies, February 1982, <br />Volume 6). The bench slopes at the East Mine were measured during the bond release inspection using <br />an inclinometer. The following chart lists the inclinometer measurements taken by reclamation zone <br />(see map 6A -5C) starting at the top of the mine. <br />Zone <br />Slope (H: V) <br />Slope (Degrees) <br />3C <br />3.31-1: IV <br />170 <br />313 <br />3.1H:1V <br />180 <br />1 C <br />2.5H:1 V <br />220 <br />4C and 213 <br />2.4H:1 V <br />230 <br />2A <br />4.0H:1 V <br />140 <br />IA <br />2.61-1: IV <br />210 <br />Average <br />2.9H:1 V <br />190 <br />The reclaimed slopes overall appeared to be stable and well vegetated. Little or no erosion was observed <br />on the hillslopes in any of the reclamation zones. In reclamation zone IA, erosion was observed in the <br />5 <br />