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The Response continues as iterated below per the Memorandum of 17 June 2011 from <br />Tim Cazier, P.E. NOTE WELL — ONLY those items needing a reply are iterated: <br />Additional Comments: Item 6 — The DRMS engineering staff uses the Galena Slope <br />Stability Analysis software (Version 5.02) to analyze slope stability. The staff used the <br />parameters recommended in the attached Table 1 and the Spencer - Wright method to <br />analyze the two cases presented: 1) `Pit Side Flood,' an d 2) the dewatered condition. <br />The staff found all analyzed failure surfaces for the Pit Side Flood to have a Factor of <br />Safety (FoS) very near or greater than 1.1. However, when the staff analyzed the <br />dewatered condition, several failure surfaces were found to have a FoS below 1.0 and <br />some surfaces originating as far as 26 feet from the slope crest with a FoS less than <br />1.1. Given the uncertainty in the soil properties and the water table, the proposed 25- <br />foot setback must have a FoS of at least 1.1 in critical areas such as the gas wells. <br />Please revise the mine plan and provide slope stability analyses to demonstrate the <br />revised mine plan will result in a FoS of at least 1.1 in critical areas. <br />Subsequent to discussion between C.G.R.S. and Tim Cazier (OMLR), and clarification <br />of the same; Varra Companies, Inc., will maintain a fifty (50) foot setback of its <br />extraction limits from existing oil and gas facilities (i.e., wells, tanks and batteries) and <br />thirty (30) feet from related existing lines, until such a time that subsequent data and <br />analysis supports a closer separation, as determined under a Technical Revision to the <br />permit. <br />Varra Companies, Inc. correspondence of 6 July 2011 to the Colorado Office of Mined Land Reclamation <br />(OMLR) in suplemental reply to OMLR correspondence of 21 June 2011 — Western Sugar Reclamation Land <br />Development Project — M- 2010 -049. <br />2 <br />