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The volume of natural fines from Phase 2 to be replaced in the pit is 30% x 331,000 cy =99,300 cy. <br />No overburden is available for backfilling since the clean overburden was placed in the staging azea <br />and the contaminated overburden was placed on the FMM property off the permit azea. <br />To backfill the perimeter of the excavation (2950 ft) from a 1H:1 V slope to a 3H:1 V slope requires <br />52,700 cy, therefore, 99,300 - 52,700 = 46,600 cy is left over and must be filled in the pit. The extra <br />fill will be used to create slopes of between 3H:1 V and 6H:1 V, as shown in the reclamation plan. <br />The bottom of excavation is expected to be 4438' for a gravel zone of approximately 18-21 feet <br />thickness, the backfilling will raise the average level possibly 1.0 feet to 4439'. Since the ground <br />water level is expected to be 4448-4449', this would leave a lake of approximately 9.0-10.0 feet <br />depth. Once Phase 2 is mined out, the remaining backfilling of overburden will occur during the <br />initial overburden removal of Phase 3 and then Pit Lake #2 will be allowed to fill up to its natural <br />ground water level. This will take place well before the Phase 3 mining is fmished. <br />Once Phase 2 is mined out and all fill materials have been placed and graded, the lake will be al- <br />lowed to fill with water. Subsequently, the berm between Phase 1 and 2 will be dozed to 1' higher <br />than the expected water level to create shelf type wetlands. There will be no need to dewater the <br />lakes to do this. The dozer operator will be able to stay on fum ground while the work is done. <br />Phase 3 Minine <br />Prior to mining Phase 3, the CDPHE must issue an approval to mine in Subazea 2, which has some <br />existing petroleum contamination from the past refinery operation that must be removed. Elam will <br />provide this approval to the Division prior to entering the Phase 3 mining azea, which is approxi- <br />mately 15.1 acres. As with Phase 2, the sediment pond for Phase 3 mining will be the Phase 1 lake. <br />The azea below Trench #2 in Subazea 1 is the only portion of the property that contains salvageable <br />topsoil that is not contaminated. This area is 3.2 acres and the expected salvageable thickness is 14 <br />inches. Therefore, the volume available is 6023 cy. This material will be spread on the upper slopes <br />Gilsonite Pit 9/03 13 <br />