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EXHIBIT D <br /> Mining Plan <br /> The proposed Lamb Lakes permit boundary includes approximately 128.8 acres. Mining at the <br /> site is mostly complete, but additional marketable materials are still expected to be excavated at <br /> the site. The site currently consists of the previously mined areas and additional areas disturbed <br /> and undisturbed by mining. The existing excavated area is approximately 100 acres in size and, <br /> on average, about 15 to 25 feet deep. The mined area includes areas of backfilling and three <br /> groundwater lakes with surface areas of approximately 21 acres, 41 acres, and 17 acres. <br /> Permit Boundary Definition <br /> The proposed permit boundary generally follows the site parcel lines (see Exhibit C-1). The <br /> Cache la Poudre River delineates the northeastern boundary and the Fort Collins Irrigation Ditch <br /> follows most of the proposed western and southern permit boundaries. The permit boundary <br /> deviates from the parcel line in the southwest corner of the property to exclude an area not <br /> currently in the Home Office Mine permit. Additionally, the parcel area east of the Poudre River <br /> trail is not included in the proposed permit boundary. Markers will be placed along the north, <br /> east, and southern permit boundary to delineate the Lamb Lakes site from the existing Home <br /> Office Mine and other properties. <br /> Affected Land Boundary Definition <br /> The affected land boundary essentially follows the permit boundary. However, the Poudre River <br /> Trail, which bisects the proposed permit area from west to east and is owned by the City of Fort <br /> Collins, will be excluded from the affected area. The affected area is 128.6 acres. Between the <br /> edge of the historic mining areas and the affected area boundary, much of the land will likely be <br /> disturbed by access roads, slurry wall installation, or other reclamation related activities. <br /> Nature of Deposit to be Mined <br /> Un-mined portions of the Lamb Lakes site are composed of Pleistocene and recent age valley-fill <br /> materials that make up the alluvial floodplain of the Cache la Poudre River. The alluvial <br /> material may have previously occurred naturally at the surface, but past mining and reclamation <br /> activities appear to have placed soil cover over most of the site. The alluvial deposit extends to a <br /> variable depth of 15 to 25 feet below the ground surface. Upper layers of the Pierre Shale <br /> Formation underlie the alluvial material in and surrounding the proposed permit area. The <br /> relatively impermeable characteristics of the shale create a bottom seal for reservoir construction <br /> and water storage development. <br /> Sand and gravel for use as construction materials have been the primary products produced from <br /> the proposed Lamb Lakes site. It appears that mining setbacks from the proposed permit <br /> boundary have ranged from 25 to 50 feet. At this point, backfill and grading has created <br /> approximate 3H:1 V slopes from top of bank to the lake water surface and it is believed that these <br /> slopes continue to the lake bottom. Distances from the proposed permit boundary to the water <br /> surface of the lakes ranges from 50 to 200 feet. The slurry wall for final reclamation will be <br /> constructed within this setback area. <br /> Lamb Lakes <br /> DBMS 112 Permit Application Page 4 <br />