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and naturals to between 3.OH:1.OV and 6H:1 V. It is expected that 30% of the raw sand and grave] <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 area for backfilling. <br />As Phase 1 is mined out, [he contaminated overburden from Phase 2 will removed and placed in the <br />designated off site FMM farming area 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 area 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 Mining(if trench is installed <br />The expected raw gravel obtained from the mining of Phase 1 is an average thickness of <br />approximately 18' x 13.7 acres = 398,000 cy. Subtracting 30% for naturals leaves 278,600 cy sand <br />and gravel to be sold. This is 417,900 tons. Using an average annual sale figure of 200,000 total <br />tons (gravel and asphalt), the life of the Phase 1 reserve will be approximately 2.1 years. The actual <br />life may fluctuate somewhat in response to supply and demand, fluctuations in mining depth, etc. <br />The volume of natural fines from Phase 1 to be replaced in the pit is 30% x 398,000 cy =119,400 <br />cy. No overburden is available for backfilling since the clean overburden was placed in the staging <br />area and the contaminated overburden was placed on the FMM property off the permit area. The <br />backfilling of fines to a minimum final slope of 3H:1 V will occur on an ongoing basis. <br />To backfill the perimeter of the excavation (3020 ft) from a 1H:1V slope to a 3H:1V slope requires <br />54,000 cy, therefore, 119,400 - 54,000 = 65,400 cy is left over and must be filled in the pi[. The <br />extra fill will be used to create slopes of between 3H:1V and 6H:1V, as shown in the reclamation <br />plan. The bottom of excavation is expected to be 4438' for a gravel zone of approximately 18-21 <br />feet thickness and the backfilling may also raise the average level possibly 1.0 feet [0 4439'. Since <br />the ground water level is expected to be 4448-4449', [his would leave a lake of approximately 9.0- <br />10.0 feet depth. <br />Gilsoni[e Pi[ 1/04 13 <br />