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is included in appendix A. A v-shaped spillway will be installed from the pond back to the pit as a <br />safety measure in case the automatic sensor fails. The bottom of the v-ditch will be at the level of <br />3.Ofeet, or 1.0 feet below the top of the sediment pond <br />Once the sediment pond and trench system aze functioning properly, the mining of Phase 1 can be- <br />gin. As described eazlier, all overburden will have been already stripped and permanently placed in <br />the staging azea. Operations within the pit azea will be limited to the hours of 6:00 A.M. to 7:00 <br />P.M. Monday through Saturday and will occur intermittently throughout any given yeaz. Once the <br />overburden is placed on the staging azea, a portable truck scale, scale house, portable crushing and <br />screen plant and portable asphalt plant will be brought to the site and set up in the staging area. <br />Mining will be done by dozers, front end loaders or excavators within the pit and a ramp will be <br />maintained to the staging azea for the equipment. Mining will occur from the south to the northeast. <br />The mined pit slope will be 1.OH:1.OV although this slope will be later backfilled with overburden <br />and naturals to between 3.OH:1.OV and 6H:1 V. It is expected that 30% of the raw sand and gravel <br />will be designated as naturals or fines which will not be sold. This material will also be brought <br />back into the Phase 1 pit azea for backfilling. <br />As Phase 1 is mined out, the contaminated overburden from Phase 2 will removed and placed in the <br />designated off site FMM farming azea as approved by the CDPHE. Based on the expected top of <br />the gravel deposit (4457) and the existing contours of this phase, an overburden average thickness <br />of 3.0' over the azea of 9.0 acres yields 23,958 cy. This amount combined with the 5733 cy removed <br />from Trench # 1 yields a total of 29,691 cy of contaminated overburden removed from the site. <br />Phase 1 Minine <br />The expected raw gravel obtained from the mining of Phase 1 is an average thickness of approxi- <br />mately 18' x 13.7 acres = 398,000 cy. Subtracting 30% for naturals leaves 278,600 cy sand and <br />gravel to be sold. This is 417,900 tons. Using an average annual sale figure of 200,000 total tons <br />Gilsonite Pit 9/03 11 <br />