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-55- <br />xVII. Backfilling and Gcading (2.05.3(b), 2.05.3(a), 2.05_.4 <br />6+IECC stated in its original permit application that numerous slope <br />failures and rock falls have been identified during the course of its <br />study of the Mt. Gunnison lease property. Landslides and rockfalls <br />identified during their study are delineated on map Exhibit 2.7.9.A. <br />However, WECC also observed that it believes such slope problems would <br />have "minimal effect on the operation...such areas, if they are <br />encountered, can be stabilized or removed when the facility is built". <br />(Page 2-242, permit application.) <br />In order to judge the credibility of 'iTFX.C's permit application <br />statements regarding slope stability, the Division requested the <br />submission of supporting information. WEC'C responded by submitting a <br />report prepared by Geo-hydro Consultants, Inc., entitled "Landslide <br />Study, Geo-Hydro Consultants, Mt. Gunnison No. 1 Mine", included within <br />the revised permit application as exhibit 2.7.9. This report, prepared <br />in conformance with the current state-of-the-art, includes design <br />recommendations for the surface facilities to be constructed within the <br />landslide deposit delineated in the surface facility area of the Mt. <br />Gunnison site. One of the design recommendations forwarded within the <br />report is the installation of a dewatering system consisting of <br />horizontally inclined dewatering wells installed throughout the <br />affected area, specifically within the portal bench and access road. <br />Specific engineering design plans for this system have been included <br />within the permit application. In addition, intricate bin-wall <br />retaining structures were subsequently included within the design <br />documents in the permit application. <br />Additional concern was also focused by the Division upon landslide <br />deposits above Beaver and Minnesota Reservoirs. The Division's concern <br />regards possible effects of subsidence upon these previously unstable <br />deposits. This concern was addressed by WECC. <br />wECC proposes to return all surface disturbed areas to approximate <br />original contour, with the exception of the waste disposal piles. <br />However, WECC has identified an area of the surface facilities which <br />has been the focus of historic and recent landslide activity. <br />Subsequently, the Division required WECC to demonstrate, through <br />appropriate geotechnical analyses, that the proposed backfilled <br />surfaces would satisfy the required static slope safety factor of 1.3. <br />Exhibit 3.2.2. within the permit application, "Report on Stability <br />Analyses and Recommendations for Reclaimed Surface Facilities at the <br />I4ECC Mt. Gunnison No. 1 Mine", prepared by bierrick and Company, <br />presents the results of the required stability analyses and <br />recommendations for reclamation of the affected area. Merrick and <br />Company's recommendations include maintenance of the permanent ground <br />water dewatering system and Backfilling many of the surface facilities <br />