Laserfiche WebLink
• 1.0 INTRODUCTION <br />The Bowie Mine No. 2 is a subsurface coal mine owned and operated by Bowie Resources, LLC <br />(Bowie). The Bowie Mine No. 2 is located north of Colorado State Highway 133, approximately <br />3.5 miles northeast of Paonia, Colorado, Location of the site is indicated on the attached <br />Drawing 1. The mine produces approximately 5 million tons of coal per year. Coal waste from <br />the wash plant as well as some high ash coal is currently disposed at coal waste disposal areas <br />located immediately north of Colorado State Highway 133. <br />Buckhorn Geotech, Inc. (BGI) was retained by Bowie to evaluate stability of a proposed new <br />coal wastepile ("gob pile") site under consideration for use once the current wastepile has <br />reached its capacity. This wastepile is designated "Gob Pile No. 3". The Gob Pile No. 3 site is <br />located between the Fire Mountain Canal and Highway 133 and is roughly 1/3 mile southwest of <br />the existing Gob Pile No. 2. <br />A geotechnical site investigation was conducted in December 2006 to characterize the subsurface <br />conditions at the proposed footprint. Laboratory testing was subsequently conducted on soil <br />samples from the foundation as well as placed gob material from Gob Pile No. 2. The <br />geotechnical investigation and laboratory testing support limiting equilibrium stability <br />evaluations for proposed gob configurations. We are pleased to present this report summarizing <br />our stability evaluation of the proposed Gob Pile No. 3. <br />. 1.1 Scope of Services <br />Stability evaluations conducted for the proposed Gob Pile No. 3 are based on a geotechnical site <br />investigation, short-term groundwater monitoring, and previous and on-going laboratory testing. <br />A geotechnical investigation was conducted by BGI in December 2006. Seven boreholes were <br />drilled to depths up to 90 feet at the gob pile footprint. Open standpipe piezometers were <br />installed to monitor groundwater conditions. Groundwater conditions were monitored in <br />December 2006 and January 2007. Additional drilling was conducted at the existing Gob Pile <br />No. 2 to sample and test placed gob. Shear strength parameters for gob and foundation soils <br />were estimated based on triaxial compression tests conducted on thin-walled samples collected <br />during the geotechnical investigation. Stability of the proposed gob pile was evaluated using <br />conventional two-dimensional limit equilibrium analyses. <br />2.0 SITE DESCRIPTION <br />The proposed Gob Pile No. 3 is located north of State Highway 133 and south of the Fire <br />Mountain Canal, as indicated on Drawing 1. The proposed new site is located approximately 1/3 <br />mile southwest of the existing Gob Pile No. 2. The anticipated wastepile footprint is <br />approximately 1,350 feet long and 600 feet wide. The area of the footprint is approximately <br />15 acres. The ultimate capacity of the wastepile will depend on the selected gob configuration <br />• and actual wastepile footprint. <br />Bowie Gob Pile No. 3 stability report <br />Project #06-481-002 <br />Pnge 4 of 17 <br />