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INTRODUCTION Aggregate Industries - WCR, Inc. proposes to mine the property located in the south half of section 9, Range 67 West, Township 2 South, in Adams County. The property is bounded by 104~h Avenue on the south, the South Platte River on the west, the Fulton Ditch on the east, and the Lafazge Howe/Haller Pit to the north. The proposed mining operation will extract gravel reserves from locations adjacent to man-made structures- The rules and regulations of the Division of Minerals and Geology require that any mining within a 200 foot setback of a man-made stmcture show through 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 geotechnical results and methodology used in the analysis of the mining and reclaimed slopes and their affects on all man-made structures. Recommendations regazding acceptable setbacks from man-made structures have also been included. OVERVIEW The Division of Minerals and Geology mining plan proposes that the property will be mined in one large cell. A slurry wall will be placed around the entire mining area prior to any mining taking place. The reclamation plan, Exhibits E and F, propose the future use for this property to be a water storage reservoir. The mined slopes will be reclaimed with a 3H:1V embankment constructed from overburden materials. Concurrent reclamation is planned such that the reclamation embankment will be constructed as the mining progresses. The reservoir will cover an estimated 143 surface acres when full. Actual surface area will depend on the final configuration of the reservoir after reclamation is complete. GEOTECHNICAL DATA In order to evaluate the slope stability of the proposed mining embankment, conservative soil strength values have been estimated for each soil type. These estimated values are _ based on soil strength values determined for similar slope stability analyses performed for existing gavel operations along the South Platte River in this region. A detailed geotechnical investigation needs to be performed to determine the actual soil strength values for this site. A final slope stability analysis incorporating the actual soil strength values should then be preformed- This analysis would likely show that the proposed setbacks could be reduced. Table 1 represents a summary of the soil strength values that were used in this stability analysis.