2012-02-16_REVISION - M2002020 (9)

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Species Rate (lbs PLS /acre) Intermediate Wheatgrass 5.0 Russian Wildrye 4.0 White Sweetclover 1.25 Rates are for broadcast seeding. be one of the last steps in the mining and reclamation, although concurrent mining and slurry wall installation is possible. Mining Methods The deposit will be dry mined using dewatering trenches and pumps. Following dewatering of the ponds, dewatering trenches will be cut along the perimeter of the pit bottom to keep the deposit dry during mining. Pumps will be used to remove the water that drains from the deposit and surrounding alluvium. If necessary, water from the trenches will be circulated through a settling basin prior to it being discharged to the adjacent 35` Avenue drainage ditch (see Exhibit C -5). Earth Moving When the alluvial material is sufficiently dewatered, the aggregate material will be recovered using equipment typical for sand and gravel mining operations. Earth moving equipment may include, but are not limited to dozers, loaders, scrapers, and excavators as mining progresses to a depth of 50 to 60 feet below the surface. Since the mining will take place in the center of the ponds and a previously mined area, very minimal topsoil and overburden is expected to be available. As mining progresses, however, any topsoil and overburden encountered will be removed, stockpiled, and used for reclamation activities. Stockpiles will be created parallel to potential Poudre River flood flows. Topsoil and overburden necessary for reclamation of the mine pit will be stockpiled near the pit or used as berm material along the perimeter of the pit. Topsoil and overburden stockpiles will be configured to have side - slopes no steeper than 2H:1 V. If the stockpiles are inactive for more than one growing season they will be seeded with the fast growing grass seed mixture below. Since reclamation will take place concurrently with mining, long -term stockpiling is not anticipated. Since the stockpile materials will continually be used for reclamation, the stockpiles will likely be disturbed on a frequent basis and seeding the stockpiles may not be practical during the course of the operation. If stockpile seeding is not used, surface roughening will be maintained to limit wind and water erosion. Non - marketable material excavated from the pit (i.e. clay and silts) will also be removed, stockpiled, and used for backfilling existing mine pits and other reclamation activities. The non - marketable material stockpiles will be created parallel to potential Poudre River flood flows Greeley 25` Avenue Site DRMS 112 Permit Amendment Application Page 7