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1 Mining Evaluation lferracnn <br />Ingleside Quarry Highway 287, Larimer County, Colorado <br />Terracon Project No. 20035106 <br />Page 4 <br />rock scaling may be required to minimize the potential of rock fall from loose or dislodged <br />rock from blasting operations. Slope stability for the reclaimed rock slope was analyzed <br />using the Stabl computer program. Analyses were performed using a range of assumed <br />material strengths. Using very conservative strength values a factor of safety of greater <br />than 1.5 was determined. Slope stability calculations are included in Table 2 of this report. <br />A cross section showing the recommended final slopes is included as Figure 3 of this <br />letter. <br />It is anticipated most rock mined at the site will be moved and sold. Therefore stockpiling <br />of waste material is not anticipated. Side slopes at the north and south ends of the <br />finished quarry may be constnacted with rock rubble on minimum 2 to 1 slopes. These <br />slopes have calculated factors of safety greater than 1.5. <br />Blasting for final slopes should be carefully designed and controlled to minimize breakage <br />and loosing of rock to minimize potential future rock fall. All blasting charges should be <br />designed to minimize damage to adjacent areas and structures. Vibration monitoring of <br />blasting operations is recommended. <br />Geologic hazards at the site in general are limited to potential rock fall and slope failure. <br />Good drainage should be provided during mining operations and after quarying is <br />completed. Final grading should be done to reduce the potential for ponding of water and <br />to reduce erosion. Removal of rock during quarrying operations to recommended slopes <br />following proper procedures should minimize potential geologic hazards on the site and <br />adjacent properties as the geologic hazards relate to the mining operations. <br />Assuming a final quarry floor level with the lower access road or at approximate elevation <br />5600 and the setback and benching configuration recommended in this report <br />approximately 7.5 million cubic yards or 15 million tons of remaining rock is available for <br />quarrying. Additional quantity of rock may be obtained if the final quarry floor is deepened. <br />However the quality of the deeper material may be of lesser quality. <br />Sincerely, <br />l~errauon <br />~'/`>~? <br />Neil R. rrod, P.G. <br />Senior Engineering Geologi: <br />,`ter. 2575 . f9~ <br />AIPG <br />y ~~a <br />0 <br />i~~~ R SHEPPto <br />' m J. Attwooll, P <br />Senior Geotechnical <br />