2014-11-14_REVISION - C1981035 - Laserfiche WebLink

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Tom Bird, GCC Energy, LLC C- 1981 -035 / TR -20 / AR #2 14- Nov -2014 Page 5 of 7 above. (Generally, compaction tests are conducted at least quarterly, if any material is placed in a given quarter, and the results are included with the quarterly report required by 4.10.2.) h) Section 2.05.4 of the permit refers to the Trautner report for determination of cover material. Subsection 6.7 of Trautner addresses placement of cover material, and refers the reader to the Appendix C (by CDS Environmental) of the report. Page 5 of the CDS report (Appendix C) recommends the following: apply 6 -8 inches of a high clay soil to the final surface of the waste bank, and roto -till 15 -18 inches deep. Then, apply a 24 inch top soil cap suitable for plant growth. For the Refuse Pile, the permit requires 3.5 feet of "cover ", topped with 6 inches of "plant growth medium ". i) Does GCC wish to utilize a different reclamation and cover strategy (i.e. the CDS plan) for the West Waste Bank than that which is currently permitted for the Refuse Pile, per Rule 4.10.4(5)? Based on GCC's 06- Oct -2014 response, the answer to this question appears to be, "Yes ". This item is resolved. ii) The permit text should be revised to include the cover requirements for the West Waste Bank just as it does for the Refuse Pile. Section 2.05.4 was revised as requested. This item is resolved. 7.0 Slope Stability Analysis a) With the 14- Aug -2012 report, Trautner evaluated waste bank heights of 10 and 20 feet, and outslopes of 2h:1v, 2.5h:1v, and 3h:1v. All of the analyses produced a factor of safety (FOS) which exceeded the minimum static FOS of 1.5 required by Rule 4.10.4(2). The report did recommend that slopes of 2h:1v should be avoided, due to construction limitations. b) With the February 2013 submittal, a new stability analysis from Trautner (dated 12 -Feb- 2013) was provided which utilized the specific dimensions now proposed for the West Waste Bank. This analysis considered a pile height of 30 feet with a face constructed at 2.5h:1v. The result is a predicted FOS of 1.69, which exceeds the required minimum of 1.5. c) (New) GCC's 06- Oct -2014 submittal included a Revised study by Trautner, dated 30 -Sep- 2014. The Slope Stability Analysis fails to incorporate the configuration evaluated by Trautner in Feb -2013, i.e. the pile height of 30 feet, with a 2.5:1 face. Now that the Trautner study has been updated, it does not make sense to omit the proposed design from the Stability Analysis. Please update the Revised study to include the proposed design configuration of the West Waste Bank. Permit Maps 1. Map King 1 -007 Operation Plan & Surface Features a) Please identify on this map the various features discussed in the permit text, specifically the Fan Bench, the Tipple Bench, and the Shop Bench. The location of the proposed West Waste Bank is identified as a "Coal Storage Area" on this map. Please clarify in the maps and text