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Mine Phasing Summary <br /> Total Acreage Duration <br /> Mine Phase (acres) Mining Status (years) <br /> Phase 1 75 Complete - - - <br /> Phase 2 45 Complete - - - <br /> Phase 3 20 In Progress 3-5 <br /> TOTAL 140 3—5 <br /> Mining Methods <br /> Mining methods include activities typical of sand and gravel mining techniques statewide. Since <br /> groundwater is being encountered during the mining of Phase 3, the deposit is being dry mined <br /> using dewatering trenches and pumps. Prior to excavation, trenches have been advanced along <br /> the perimeter of the mining area to begin dewatering the sand and gravel reserve. The trenches <br /> extend through the overburden and alluvium to bedrock. Pumps are used to remove the <br /> groundwater that drains from the deposit and surrounding alluvium into a settling pond (sump) <br /> prior to it being discharged to adjacent groundwater recharge ponds (see Exhibit C-5, Pre- <br /> Mining/Mining Plan Map). As excavation progresses in the mining area, dewatering trenches on <br /> the pit floor will continue to collect groundwater, keeping the deposit material relatively dry. <br /> Earth Moving <br /> The Phase 3 area being mined is situated between previously mined and backfilled areas of <br /> Phase 2 and the active material storage and processing area in Phase 1. The area to be mined is <br /> prepared by first stripping topsoil and overburden and almost immediately using this material to <br /> backfill previously mined areas. If topsoil and overburden material stockpiles are used, they will <br /> be created adjacent to previously mined areas needing backfill. Once topsoil and overburden are <br /> removed, the exposed gravel is excavated in lifts for processing. Since the material is in <br /> unconsolidated deposits, no blasting is required. <br /> Each preparation area in Phase 3 may be as much as 150 feet wide and a hundred feet in length. <br /> Where it is found, topsoil material is being stripped and stockpiled separately from the <br /> underlying, deeper subsoil or overburden material. This topsoil layer contains most of the <br /> organic matter and is used strategically during reclamation. After topsoil stripping and <br /> stockpiling, the overburden is stripped and used for backfill. <br /> The active mining face extends no more than about 150 feet in width. During mining and prior <br /> to reclamation, the active mining face and side slope adjacent to Phase 2 will be a nearly vertical <br /> to ' H:l V slope (see Exhibit C-5, Pre-Mining/Mining Plan Map). The Phase 3 mining will <br /> remove the 10 to 15 feet of quality aggregate material remaining between the Phase 2 backfill <br /> and the Phase 1 mine pit. As the mining face progresses to the northwest, the area behind the <br /> mining activities is backfilled to stabilize the side slope adjacent to Phase 2. So that reclamation <br /> Timnath Connell Pit <br /> DRMS 112 Permit Amendment Application Page 6 <br />