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INTRODUCTION <br /> Darwin Derr proposes to mine the property located in the Northeast 1/4 of Section 4, <br /> Township 5 North, Range 65 West, Sixth P.M. in Weld County. The property is bounded <br /> by Balsam Avenue on the west, adjacent to an Aggregate Industries mining operation, <br /> and private property on the north, south, and east. State Highway 263 (8th Street) is less <br /> than a quarter of a mile south of the subject property. The proposed mining operation <br /> will extract gravel reserves from locations adjacent to man-made structures. The rules <br /> and regulations of the Division of Reclamation, Mining, and Safety (DRMS)require that <br /> any mining within a 200 foot setback of a man-made structure show thorough <br /> engineering analysis that the proposed mining will not cause damage. The accepted <br /> method of demonstrating this is through a slope stability analysis. This report contains <br /> an overview of the prior geotechnical investigation results by Terracon and Two Rivers <br /> Testing, and the methodology used in the analysis of the mining slopes and their <br /> estimated affects on all man-made structures. Recommendations regarding acceptable <br /> setbacks from man-made structures have also been included. <br /> OVERVIEW <br /> The DRMS mining plan proposes that the property will be mined in 7 phases. The <br /> reclamation plan, Exhibits E and F, propose the future use for this property to be a <br /> slurry wall lined water storage reservoir. The mining will occur at 3H:1V slopes. <br /> Concurrent reclamation is planned such that the reclamation embankment will be <br /> constructed as the mining progresses. The reservoir will cover an estimated 30 surface <br /> acres when full. Actual surface area will depend on the final configuration of the <br /> reservoir after reclamation is complete. <br /> GEOTECHNICAL DATA <br /> Preliminary geotechnical investigations have been performed by Terracon and Two <br /> Rivers Testing. J&T Consulting, Inc. (JT) estimated soil strength parameters based on <br /> the information from the geotechnical investigation, which was provided to JT by Darwin <br /> Derr, and other stability analyses that have been performed on gravel mining operations <br /> along the front range. Table 1, on the following page, represents a summary of the soil <br /> strength parameters that were used in this stability analysis. <br /> 11111 Broken Arrow Investments,LLC-Derr Pit Project <br /> J&T Consulting, Inc. Slope Stability Analysis <br /> Page 1 <br />