2002-04-12_PERMIT FILE - M2002052 (26)

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EXHIBIT D -MINING PLAN Overview The applicant proposes to develop the site as a sand and gravel mining and processing operation. Approximately 25 acres of the total permit area acreage of approximately 49 acres will be mined (see Exhibit C, Pre-Mine and Mine Plan Map. The edges of the reservoirs will be reclaimed to an irregular shoreline with wetland vegetation gradually establishing itself. The post-mining land use of the property is for water storage and wildlife habitat. The Reclamation Plan assumes the cost for restoration of the mining area and wildlife habitat Mine Plan Prior to the commencement of mining the applicant will excavate a trench from the flow line of the Little Thompson river to the east mining limit as shown on Exhibit C mining plan. Water discharge permit is applied for as part of the water replacement plan in Exhibit G. 404 permit through the U.S. Army Corps of Engineers will be obtained if needed. This trench will be graded to the average low flow level of the river. This will allow draining of ground water to a lower level by advancing the trench along North and South mining limits just ahead of mining. Material will be mined wet. As mining progresses in a Westerly direction, a dewatering point will be established at the low point of the lake bottom point w. The pump location for discharge to the Little Thompson River is to be located in the southeastern area of the site. A CPDES discharge permit will be obtained for this function. This will allow for pumpdown at intervals to allow dry mining and for reclamation in stages as mining progresses. The de- watering activities and plant process-water consumption is addressed by a Gravel Well Permit Application and Temporary Substitute Supply Plan. Applegate Group Inc. is preparing the plan for submittal to the State Engineer's Office. A copy will be provided as part of Exhibit G when complete. Mining will be done by hydraulic excavator working 20 - 25 foot strips running North & south. Walls at mining limit will be excavated to approx 1:3 slope except in areas of high quality gravel. Overburden of an average six foot depth will be removed at a distance about 75 feet ahead of the mining of the gravel. Most of the overburden will be transported to adjacent property owned by Western Equipment for fill purposes. Since most material will be sold without processing it will remain stockpiled where the excavator leaves it until sold. Some material will be processed by wheel loader transport to the screen & crushing plant. The area inside the mining limit boundaries will be stripped of topsoil to a depth of approximately 1 ft, staying ahead of the trench and mining operation as it progresses from East to West.. Topsoil from the first phase will be stockpiled in a revegetated pile in the extreme North of the mining area. Topsoil will also be stripped from the plant area. Additional topsoil removed will be used for concurrent reclamation work as the mining progresses. Extra topsoil will be sold and the revegetated pile will be used for the final stage of reclamation. Mining will continue with this methodology through the mine limit area encompassing a probable ] 0 years duration, but could be extended or shortened based on market conditions. 2RR app CDMG 112