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• J.E. Stover & Associates <br />Terracon Project No. 65995058 <br />June 3, 1999 <br />GEOTECHNICAL CONDITIONS <br />Maxim Technologies, Inc. (Maxim) and Lambert and Associates (Lambert) have performed <br />previous geotechnical studies at the site. Those reports provided for our review, which form <br />the basis of the geotechnical data for the stability evaluations, include: <br />Lambert and Associates, "Geotechnical Engineering Study, Coal Conveyor System, <br />Bowie Number 2 Mine, Paonia, Colorado", Project Number M96177GE, dated <br />October 7, 1998; <br />Maxim Technologies, Inc., "Preliminary Geotechnical Engineering Study, Bowie <br />Mine No. 2 Surface Facilities, Delia County, Colorado", Job No. 5002-60-2655,01, <br />dated July 10, 1996 <br />Maxim Technologies, Inc., "Addendum to Preliminary Geotechnical Engineering <br />Study, Bowie Mine No. 2 Surface Facilities, Delta County, Colorado", Job No. 5002- <br />60-2655.01, dated October 17, 1996; and, <br />• Maxim Technologies, Inc., "Additional Stability Analyses, Proposed Portal Road <br />Cuts and Topsoil Pile, Bowie Mine No. 2, Delta County, Colorado", Job No. 5002- <br />60-2655.05, dated January 7, 1997 <br />Review of the geotechnical data contained in the reports indicates the proposed mine surface <br />facilities will be located on a southeast facing slope which has been mapped as an ancient <br />landslide of unknown age. The landslide has occurred on steep terrain formed by horizontally <br />bedded sandstone and shale of the Mesaverde Formation. Apparently, no discernable head <br />scarp, toe bulge or tension cracks were observed that would indicate the landslide was active <br />at the time of Maxim's field exploration, or has been active in the recent past. The landslide <br />material has been characterized as having been drained and consolidated into a highly over- <br />consolidated clay matrix surrounding scattered to numerous boulders. <br />Maxim has characterized the existing topography to have natural slopes on the landslide and <br />at the location of the proposed surface facilities varying from 3H:1V (horizontal:vertical) to <br />5H:1V. However, several excavations have apparently been cut into the landslide materials to <br />construct an access road to the mine workings, with slope ratios varying from 1.5H:1V <br />• (horizontal:vertical) to 2H:1 V. In 1996, Maxim reported that these existing cut slopes generally <br />appeared to be stable. <br />3 <br />