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Bruce Park Landslide <br />Bowie Mine #2 <br />0 PURPOSE AND SCOPE <br />Project No. 25-196 <br />This report presents the results of our geotechnical investigation and evaluation of the <br />Bruce Park Landslide adjacent to Terror Creek Reservoir near Bowie, Colorado (Figure 1). The <br />subsurface investigation and evaluation was conducted to provide our analysis and opinions <br />regarding the possible effects of nearby coal mining activities on the stability of the existing <br />landslide. The findings of our investigation and our opinions relating to potential mining impacts <br />on the existing landslide are presented in this report. <br />The site investigation consisted of geologic reconnaissance and exploratory drilling to <br />investigate subsurface conditions. Inclinometer measurements and piezometer readings were <br />also conducted. The drilling was observed by a representative of Yeh and Associates. <br />Inclinometer and piezometer readings were performed by Bowie Resource personnel. Samples <br />obtained during the field exploration were examined by the project personnel and representative <br />samples were subjected to laboratory testing to determine the engineering characteristics and <br />strengths of materials encountered. We were also provided with the following reports and <br />letters: <br />• Addendum to Geotechnical Report, Bowie Resources, Limited, GEI Consultants, <br />Inc., July 2002. <br />• Norfleet, James, Letter to Joseph Dubash, Division of Water Resources, Water <br />Division Four, June 11, 2003. <br />• Seismic Data by email from Peter Swanson, Research Geophysicist, National <br />Institute for Occupational Safety and Health (NIOSH/CDC), Spokane Research <br />Laboratory, 315 E. Montgomery Ave., Spokane, WA 99207 <br />PROJECT BACKGROUND <br />This report addresses the effects of longwall mining to the stability of an existing <br />landslide adjacent to the the Bruce Park (a.k.a. Terror Creek) Reservoir Dam. The landslide <br />area was described in a previous geotechnical investigation by GEI Consultants, Inc. in April of <br />2001. We understand the landslide initially moved during the early to mid 1980s. Based on our <br />observations, it appears that the movement of the landslide since that time is in excess of tens <br />of feet. The State of Colorado Division of Water Resources expressed concerns that as the <br />coal mining activity advances towards the landslide and the resulting seismic events from roof <br />collapse of the mine may further reduce the stability of the landslide. The Department's <br />1