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reclamation process. Overburden and topsoil stockpiles that will not be used within six months of <br />excavation will be seeded to establish a vegetative cover from stabilization and protection from <br />erosion. Typical stripping depths for topsoil and overburden in the mining area are one-half and <br />six feet respectively. <br /> <br />Aggregate materials will be excavated by using explosives to free the rock from the matrix. All <br />explosive work on the site will be performed by a licensed third party. The explosives needed for <br />each blast will be transported to the site immediately before blast holes are loaded and excess <br />explosives will be removed from the site after the blast holes are loaded. No explosives will be <br />stored on site. <br /> <br />Once the aggregate material is blasted free of the rock matrix, a loader or excavator will be used <br />to handle and load it into off-road dump trucks and/or onto the conveyor feed for transport to the <br />material processing area on the adjacent Martin Marietta-owned property. Blocks of rock that are <br />too large to process (oversize material) or that will not be used as riprap will be temporarily set <br />aside adjacent to the excavation site for mechanical size reduction or use in reclamation. An <br />excavator equipped with a mechanical breaker or other mechanical means will be used as-needed <br />to reduce oversized material to an appropriate size for transport and processing. <br /> <br />7. Water Supply <br /> <br />The current quarry operation uses about 1,500 gallons of water per minute (gpm), most of which <br />is recycled water that is used at the wash plant. Some water is applied to roads for dust control. <br />Water usage is not anticipated to increase as mining progresses onto BLM lands. Water for the <br />quarry is obtained from tributary groundwater that collects in the alluvial pit and is augmented as <br />needed by water from Tallahassee Creek or the Arkansas River under a state reviewed and <br />approved withdrawal permit. Water shares are leased from the Board of Water Works of Pueblo, <br />the Twin Lakes Reservoir and Canal Company, and the Cañon City Water Department to allow <br />the use of groundwater and surface water by the mine. <br /> <br />8. Need for Active Dewatering of the Granite Quarry <br /> <br />The need for active dewatering of the pits to facilitate mining in the granite area was evaluated <br />based on observations on groundwater inflow to the current quarry operation and scoping-level <br />calculations of inflow performed by ERM (2019) and Whetstone (2020) for the project <br />Environmental; Impact Statement (EIS). Copies of the Whetstone and ERM reports can be found <br />in the EIS, and are excerpted in Exhibit G of the 112(c) permit application package. The analysis <br />by ERM used two types of analytical calculations: one for southwest linear flow towards the quarry <br />highwall and one for radial flow to a semicircle representing the northeast portion of the quarry. <br />Both calculations assumed the following conditions: <br /> <br />• The hydraulic conductivity of the granitic rocks is equal to the average of the testing data <br />(i.e., 0.0039 ft./day). <br />• Specific yield of the granitic rocks is equal to 0.01. <br />• The quarry is instantaneously excavated to full depth at time zero.