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All structures west of the gold portion of the permit area such as Highway 9, power poles, wastewater <br />treatment plant and the 16" culvert under Highway 9 will be protected from damage due to the <br />following measwes: <br />1 -the maximum mining slope for the cuts made will be 2H:1 V This slope is almost entirely in virgin <br />gravel which has held up in neazly vertical cuts for decades without problems. <br />2 - An engineering analyses is done for this condition is given in the subsequent Geotechnical <br />Stability Exhibit. This shows a very high factor of safety for loose material piled up at this angle with <br />no cohesion, which is true of these gravels, and is very conservative. Water pumping from the pit <br />does not in any way affect the slope stability of these type deposits, since the strength of these <br />materials comes from internal angle of friction and not cohesion. <br />3 - A topsoilloverbwden berm of approximately 8 feet high and 2H:1 V sideslopes will be installed <br />between the western edge of the cuts and the permit boundary, thus further protecting the facilities <br />fi~rther to the west. <br />All structures surrounding the north gravel portion of the permit cannot be affected since this mining <br />activity will not mine steep cuts, but will simply mine old piles from the past that have been built up <br />on the landscape. No problems with slope stability could occur in these areas. <br />The Columbia Ditch and the Colorado Springs pipeline to the east of the mining area cannot be <br />affected since they are so far from the mining area (min. 740 feet) and the mining area will not <br />employ any steep highwalls in the ongoing operation. Past highwalls in the northeast portion of the <br />property and east of the old 110 operation aze also very far from the 2 structures (see Map C-1) and <br />the highwalls have been in place for decades without any sign of potential failwe, erosion, cracking, <br />slipping or other type of failwe. <br />The compacted dirt access road (24' width), immediately south of permit azea, leading to the <br />residential development north and west of permit known as Breckenridge Mountain Estates will not <br />be affected since the closest edge is at least 340 feet from the closest top edge of cut. This road is <br />Alma Placer 7/03 89 <br />