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<br /> <br /> <br /> 44 C1981-041 RN7 findings <br />in Tab 14. The reclamation plan for the top of the RSRDA was modified by approval of <br />PR-3, as the flat top of the waste pile is included within the designated alternative land use <br />area (see Exhibits 6C and 6C-A). The top of the pile has been gravel surfaced, and under <br />the “Industrial or Commercial” land use reclamation plan approved by PR-3, the area will <br />be left “as is” for use as a storage site for equipment and supplies associated with the <br />commercial fruit operation. The area will not be topsoiled or revegetated. The 1st Quarter <br />2007 refuse pile certification report documents that the required 18 inch minimum <br />thickness of non-toxic cover material was placed over the coal waste material on the flat <br />top of the pile. A short segment of existing Access Road 1 will be left in place for the <br />postmining use. It will connect to the upper end of proposed Access R oad 1A, to provide <br />access to the storage area on top of the RSRDA. <br /> <br />The lower three benches of CRDA-1 and CRDA-2 were covered with the approved <br />thickness of non-toxic cover, seeded, and mulched in the late summer/fall of 1994. Final <br />reclamation of the upper benches was conducted in the spring of 2002. <br /> <br />Geotechnical analyses for CRDA-1, and CRDA-2, are provided in Appendices 13-4 and <br />13-5 of the application. CRDA-1 has been constructed with three rock underdrains, and <br />construction specifications include 2:1 slopes with 10' wide benches on 30' vertical <br />intervals. The benches are sloped to the inside and graded to drain to perimeter ditches <br />along the sides of the pile. CRDA-2 specifications are similar, with the exception that pile <br />design does not incorporate underdrains, and slope between benches is not to exceed 2.5:1. <br /> <br />Stability concerns associated with higher than anticipated water levels in Piezometer <br />CRDA-01 resulted in suspension of waste disposal at the site in 1988, pending drainage <br />modifications and stability re-evaluation. Between 1988 and 1993, the lower three benches <br />were regraded to provide for better slope stability and drainage. Surface drainage was <br />improved by the construction of diversion ditches that allow surface runoff to exit around <br />the pile instead of contacting the face. <br /> <br />A stability evaluation was performed in the spring of 1994 by Western Engineers, Inc. As <br />a part of the study, pump testing was conducted in existing piezometers and 30 additional <br />piezometers were installed to evaluate phreatic surfaces and pore pressures. The results of <br />the study showed the pile to be stable as designed. Critical water levels were defined for <br />each of the 30 new piezometers. Based on the study results, the operator was permitted to <br />resume waste disposal at CRDA-1 in 1994. The operator has committed within the permit <br />to monitor the 30 piezometers quarterly, and if water level in any of the piezometers reaches <br />critical target depth as listed on Table 18-4, stability of the pile will be reevaluated and <br />corrective action taken if necessary. <br /> <br />CRDA-1, and 2 was monitored throughout construction. Monitoring included: <br /> <br />1. Piezometric monitoring of the coal processing waste embankment; <br />2. Monitoring of side slopes to maintain a maximum slope angle of 2:1 between <br />benches on CRDA-1, and 2.5:1 on CRDA-2; <br />3. Monitoring compaction of constructed lifts; and