2008-11-20_PERMIT FILE - M2008078 (2)

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I - INTRODUCTION GP Ranches, LLC (GP) proposes to mine the property located east of the Town of Lamar, Colorado. More specifically the property is located in the South 'h of the Southeast % of Section 28, the Northeast % of Section 33, and the Northeast % of the Northwest % of Section 33, Township 22 South, Range 46 West, Sixth P.M. in Prowers County, Colorado. The property is bounded by private property on the east and west, Prowers County Road HH.5 on the south, and private property and the Town of Lamar sewer lagoons on the north. United States Highway 50 is approximately one eighth mile south of the subject property. The proposed mining operation will extract gravel reserves from locations adjacent to man-made structures. The rules and regulations of the Division of Reclamation, Mining and Safety (DRMS) require that any mining within a setback of 200 feet of a man-made structure show thorough engineering analysis that the proposed mining will not cause damage. The accepted method of demonstrating this is through a slope stability analysis. This report contains an overview of the prior geotechnical gravel investigation by J.A. Cesare & Associates (JAC) and methodology used in the analysis of the mining slopes and their estimated affects on all man-made structures. Recommendations regarding acceptable setbacks from man-made structures have also been included. II - OVERVIEW GP proposes that the property will be mined in two cells. The future use for this property is expected to be a lined water storage reservoir. The mined slopes will be reclaimed with a 3h:1v embankment constructed from clay shale and overburden. Concurrent reclamation is planned such that the reclaimed embankment will be constructed as the mining progresses. The two reservoir cells will cover an estimated 183 surface acres when full. Actual surface area will depend on the final configuration of the reservoir after reclamation is complete. 111- GEOTECHNICAL DATA A geotechnical gravel investigation for the property has been performed by JAC. J&T Consulting, Inc. (JT) estimated soil strength parameters based on the information from the JAC report which was provided to JT by GP, and other stability analyses that have been performed on gravel mining operations located in similar soils. Table 1 represents a summary of the soil strength parameters that were used in this stability analysis. Table 1 - Soil Properties Description Max dry density c Saturated Density c Cohesion s Internal Friction Angle Overburden 110 131 150 22 Sand and Gravel 110 131 0 35 Weathered Bedrock 125 141 100 18 Stable Bedrock 125 141 2000 20 West Farm Gravel Pit Slope Stability Analysis Page 1