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i~~ <br />SCOPE <br />This report presents the results of our Stability Evaluation for the existing coal <br />processing waste pile located on the eastern portion of the Golden Eagle Mine in Las <br />Animas County, Colorado (Fig. 1). Our proposal No. 95-970 was for a geotechnical <br />investigation and design for the proposed Upper Ciruela Canyon Coal Processing <br />Waste RDA to be located on the west side of Ciruela Canyon, southwest of the <br />existing coal waste area. Due to the imminent closing of the mine, Basin Resources, <br />Inc. revised our scope of services to instead provide this stability evaluation for the <br />existing coal processing waste pile. <br />This report includes results of laboratory testing of samples of the existing <br />waste to obtain information regarding the gradation and strength properties of the <br />waste, and analyses of the stability of the existing coal processing waste <br />configuration including a parametric analysis of varying waste material properties, <br />slope face configurations and water level conditions. Previous investigations of the <br />stability and/or density of the Refuse Disposal Area (RDA) located west of the <br />Golden Eagle Mine have been performed. We reviewed the strength testing <br />performed on samples of the coal refuse taken from the RDA for this investigation. <br />The conclusions presented in this report are based on our understanding of <br />the current configuration of the coal processing waste pile. Analysis related to <br />temporary or permanent surface water control was not included in the scope. We <br />should be contacted to review our conclusions if the actual configuration differs from <br />the configuration used in this report. A summary of our conclusions is presented <br />below. <br />SUMMARY OF CONCLUSIONS <br />1. The topographic map based on a flight performed on March 23, 1995 <br />indicates the lower 20 feet of the pile is sloped at about a 2.5:1 <br />(horizontal:vertical) and the upper 30 feet of the pile is sloped between <br />2.5:1 and 4:1. Basin Resources, Inc. indicated that additional coal <br />waste was placed along the face of the pile and that the current <br />9491N gE90flq CES, ING. <br />GTLT 2],797 <br />