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In order to judge the credibility of MCC's statements regarding slope stability, the <br />Division requested the submittal of supporting information. MCC responded by <br />submitting a report prepared by Geo-Hydro Consultants, Inc., entitled "Landslide Study, <br />Geo-Hydro Consultants, Mt. Gunnison No. 1 Mine," included within the permit <br />document in Exhibit 14. This report, prepared in conformance with the current <br />state-of--the-art, includes design recommendations for the surface facilities to be <br />constructed within the landslide deposit delineated in the surface facility area of the <br />West Elk Mine site. One of the design recommendations forwarded within the report is <br />the installation of a dewatering system consisting of horizontally inclined dewatering <br />wells installed throughout the affected area, specifically within the portal bench and <br />access road. Specific engineering design plans for this system have been included <br />within the permit document. In addition, intricate bin-wall retaining structures were <br />subsequently included within the design documents in the permit section. <br />The area of the surface facilities has been the focus of historic and recent landslide <br />activity. The Division required MCC to demonstrate, through appropriate geotechnical <br />analyses, that the proposed backfilled surfaces would satisfy the required static slope <br />safety factor of 1.3. Merrick and Company prepared a "Report of Stability Analyses and <br />Recommendations for Reclaimed Surface Facilities at the West Elk Coal Company, Mt. <br />Gunnison No. 1 Mine." The report presents the results of the required stability analyses <br />and recommendations for reclamation of the affected area. <br />MCC proposes to return all surface disturbed areas to approximate original contour, <br />with the exception of the waste disposal sites. <br />XI. Revegetation <br />Information regarding the vegetation in the West Elk Mine permit area is found in <br />Section 2.04.10, 2.05.4, Exhibit 31, 32, 33, Map 42, 43, and 44 of the permit document. <br />No threatened and/or endangered plant species were found anywhere within the permit <br />area. <br />Success of revegetation efforts was originally based on reference areas established in <br />July 1980 and enlarged in 1981. Reference areas were established for mixed shrub and <br />dry meadow communities and were shown on Map 44. <br />MCC proposed replacing the two reference areas with the use of a historic reference area <br />for evaluation of revegetation success. The vegetation in the historic reference area <br />resembles the expected post mining vegetation community. Data is collected in a former <br />agricultural and pasture area southwest of the facilities area as seen on Map 53. Use of <br />the historic reference area was approved in PR-7 and is presented in Section 2.05, page <br />2.05-69 of the permit application. -. <br />To establish the historic reference, three years of data are to be collected to represent a <br />dry, normal and wet year. A historic analysis was developed using precipitation data <br />from the National Climatic Data Center (NCDC) for the Paonia 1 SW station collected <br />from 1905-1965. Data from the "pre-growing" season, October through May, were <br />44 <br />