2005-07-13_REVISION - M2000016 (28)

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This Pape was updated in coniunction with the USR Application. June 23. 2005 The goundwater level lies 3 to 6 feet below natural ground level. The deposit is therefore classified as a wet alluvial deposit. However, mining operations will be carried out following dewatering. The sand and gravel is catalogued in the report Sand, Gravel, and Quarry Resources, Colorado Front Range Counties (Colorado Geologic Survey, 1974). The Site is comprised of 18 parcels owned or leased by Lafazge and will be conducted in 9 Phases, each with one to five associated mine cells. The mine phases, associated property names, status and property acres is summarized as follows, with appropriate deeds and leases located in Exhibit N: Table 1. Phase Number and Property Owner. Phase Property Name OwnedlLeased Property Acres Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 Phase 8 Phase9 Phase 9 Plant Site Area Rittenhouse Leased By Lafarge Mineral Reserves, Inc.Owned By Lafarge Lafarge West, Inc Owned By Lafarge McWilliams Leased By Lafazge Chikuma Leased By Lafarge City of Thornton Leased By Lafarge Mineral Reserves Inc. Owned By Lafarge Mineral Reserves Inc. Owned By Lafarge D&S Mining Leased By Lafazge Dreiling Living Trust Leased By Lafarge Rittenhouse Leased By Lafarge 160.0 79.4 86.1 76.7 402.5 166.6 70.0 t t 0.0 39.6 30.4 See Phase 1 Mining in phases will limit the area of disturbance at any one time. The phases depicted in Exhibit C are used to indicate the direction of mining. These phases are neither representative of the maximum area of disturbance nor do they limit disturbance to a particular phase. Methods of Mining Overview The typical mining procedure for all phases will be as follows. Any areas slated for protection will be identified in the field to assure that mining operations will beset back as appropriate. Initially, the topsoil and overburden will be stripped with scrapers and stockpiled in the designated stockpile areas identified in Exhibit C. Overburden will also be used to construct berms and as fill in the 3:1 reclamation slopes. Following stripping of the overburden, the deposit will be dry mined through the use of dewatering trenches and pumps. Overburded and topsoil stockpiles will be seeded as appropriate to prevent erosion. Prior to the mining of new cells, a dewatering trench will be constructed around portions of the perimeters. A sump hole will be created at the lowest point of the dewatering trenches. The sump holes and dewatering trenches will allow sediment to settle Ft. Lupton Pit DMG t J2 Permit Page !2 oj86