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Overburden will be stripped prior to the commencement of mining in a particular mining area. <br />There will be an abundance of overburden. Overburden will be used as backfill for the lake <br />slopes. The excess overburden will be stockpiled in the oxbow area to account for the lack of <br />overburden in this area. Also an island will be formed in Mining Area 3 with excess <br />overburden. Details of topsoil and overburden stripping are shown in the Mine Area table. <br />Mine Plan <br />Prior to mining, each pit will need to be dewatered. This will be accomplished by installing a <br />perimeter dewatering trench. The trenches will lead to a sump as shown in the maps. Water <br />will be allowed to pass through a gravel berm prior to entering the sump. This will act to filter <br />out a portion of the sediment. Two types of pumps will be used for the dewatering operation. <br />The primary dewatering pumps will move approximately 90% of the water. Secondary <br />irrigation pumps will provide water to the surrounding wetlands. This is necessary due to the <br />water table draw-down associated with pit dewatering. All discharge will pass through a <br />sediment control pond or previously mined pit, in order to allow sediment to settle. The <br />smaller sediment control ponds will be monitored for buildup. If a substantial amount of <br />sediment has accumulated, the pond will be cleaned. The sediment cleaned from the pond will <br />be placed as fill in the area currently being mined. <br />Two types of sediment ponds will be used. For primary discharge, a 200' x 20' x 4' pond with <br />2.SH:1 V side slopes will be used. A smaller pond will be used for the wetland imgation <br />discharge. A 100' x 10' x 4' pond with 2.SH:1 V side slopes will provide ample settling time for <br />flow rates of approximately 100 gallons per minute. <br />As mining progresses through the mining azeas, the pumping arrangement will continually <br />change. The locations of the pumps and ditches are approximate as shown on the mine plan <br />maps. The overall design is to dewater one pit at a time. However some overlap of two mining <br />azeas being dewatered at the same time is possible at the end of a mining area's life. Wetlands <br />surrounding the dewatered area will be supplied with water from the pits. It is expected that <br />dewatering of a pit will require approximately 1000 gallons per minute pumping capacity. <br />During initial dewatering, the pumping demand maybe up to three times the stable pumping <br />rate or 3000 gallons per minute. <br />Once the pit has been dewatered, mining will begin. Primarily, front-end loaders will be used <br />to mine the raw gravel. The slopes of the pit will be mined to 2H:1 V slopes. While mining in <br />the center of the pits a much steeper highwall will be maintained. This highwall will be laid <br />back as it approaches the mining limits. Some dozer pushing or ripping may also be used. The <br />loader will directly load to a primary crusher or into trucks which will deliver the material to <br />the primary crusher. It is anticipated that oflhighway trucks will be used to transport the raw <br />gravel to the primary crusher located in Mining Area 3. The trucks will utilize the existing <br />roads where appropriate and additional roads will be added as shown in the mine plan maps. <br />The road alignment shown on Map C-2 and C-3 are the approxiamte final location. Current <br />roads as seen in Map C-1 will be utilized until realignment is necessary. The primary crushing <br />7/22/04 Page D-4 <br />