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50 feet or three (3) times the pit depth, whichever is greatest, unless an agreement is obtained <br />from the property owner or an engineering slope stability analysis is performed. Setbacks from <br />near vertical mining excavations to the permit boundary will be 50 feet or twice the adjacent pit <br />depth, whichever is greatest. Setbacks will also be maintained for potential side slope <br />reclamation if "cut and fill" sloping is required, as discussed further in Exhibit E, Reclamation <br />Plan. The need for "cut and fill" reclamation will be determined during the mining operation <br />once overburden quantities and general pit depths are verified. <br />Topsoil and overburden material excavated from the pit will be stockpiled and used for <br />backfilling mine pit slopes and other reclamation activities. The non - marketable material <br />stockpiles will be created adjacent to the areas that will be backfilled, but not within the Lone <br />Tree Creek drainage area susceptible to flooding. When sufficient material is available in the <br />stockpile, the material will be backfilled into previously mined areas. <br />The side slopes of the mine pit will be backfilled, graded to a minimum 3H:1 V slope, and seeded <br />as mining progresses. Approximately 22,000 feet of pit side slopes will be created during <br />mining. Since reclamation is anticipated to be concurrent with mining operations, the actual <br />length of side slope requiring backfilling and grading at any point in time is expected to be far <br />less than 22,000 feet. Although the pit depth is estimated to be between 5 and 25 feet, the <br />majority of the pit depth is anticipated to be near 10 feet, therefore, the average side slope is <br />expected to be approximately 15 feet high. Once backfilling and final grading has been <br />completed in an area, the top of the slope and the side slopes will be seeded as soon as <br />practicable (based on first available seeding season). <br />Since reclamation will take place concurrently with mining, large and long -term topsoil and <br />overburden stockpiling is not anticipated. Topsoil and overburden stockpiles will be configured <br />to have side - slopes no steeper than 2H:1 V. If the stockpiles are inactive for more than one <br />growing season they will be seeded with the fast growing grass seed mixture in the table below. <br />However, since the stockpile materials will continually be used for reclamation, the stockpiles <br />will likely be disturbed on a frequent basis and seeding the stockpiles may not be practical during <br />the course of the operation. If stockpile seeding is not used, surface roughening will be <br />maintained to limit wind and water erosion. <br />Stockpile Grass Seed Mixture <br />Grass Species <br />Rate <br />(lbs PLS /acre) <br />Intermediate Wheatgrass <br />5.0 <br />Blue Grama <br />1.0 <br />White Sweetclover <br />1.25 <br />Rates are for broadcast seeding. <br />In order to gain an understanding of the extent of the mining operation, it is helpful to know the <br />acres disturbed by different aspects of the mining operation. Each aspect is listed in the <br />Connell Carr Pit <br />DRl1S 112 Permit Application Adequacy Review Response <br />