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<br /> <br />SCOPE <br />This report presents the results of our Stability Evaluation for the reclaimed <br />portal areas P3 and R1 located at the Lorencito Canyon Mine in Las Animas County, <br />Colorado. The evaluation was performed in accordance with our Proposal No. 97- <br />318, dated April 30, 1997. <br />This report includes results of laboratory testing of samples of the anticipated <br />spoil/backfill to obtain information regarding gradation and strength properties, and <br />analyses of stability of the proposed post mining topography. Recommendations <br />regarding compaction and subsurface drainage are also discussed. <br />The conclusions presented in this report are based on topographic <br />information provided by Greystone. Analysis related to temporary slopes or surface <br />• water control was not within in the scope of our investigation. A summary of our <br />conclusions is presented below. <br />SUMMARY OF CONCLUSIONS <br />1. The P3 Portal area is located at a moderately sloping hillside located <br />between two drainages in Cow Creek Canyon. A seep is located on the <br />east side of the portal area. Existing slopes in the area are on the <br />order of 2:1 (horizontal:vertical) to 3:1 slopes. Soil conditions <br />observed in the test pit consisted of a shallow layer of topsoil and <br />residual soils derived from the underlying sandstone, siltstone, and <br />shale bedrock. The thickness of the overburden soils is on the order <br />of 1 to 2 feet. The underlying bedrock is weathered, however within a <br />relatively shallow depth (on the order of 2 to 3 feet) the material is <br />judged to be hard and relatively intact. <br />2. The R1 portal will be located west of the Cow Canyon drainage. <br />Existing slopes in the area range from about 2.3:1 (horizontal:vertical) <br />to about 4:1. No signs of existing seeps were observed. Subsurface <br />conditions observed in the test trench at the R1 portal location <br />consisted of a thin layer of topsoil underlain by approximately 10 feet <br />of overburden soils. The overburden soil appeared to consist of a <br />slope-wash type material consisting primarily of a sandy clay matrix <br />LORENCITO COAL COMPANY, LLC <br />CTLR Y5,867 1 <br />