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CESPK-CO-R Page 2 Public Notice Number 200175036 I•.`. ;• Mining would commence at the 51.51-acre Mining Area B, proceed to areas C, D, and then E, which includes the east end of the facilities site. Mining Area A, also known as the Renewable Resource Area, would be mined for additional material during the mining of the other areas. There aze not any current plans to mine Areas 1? and G. However, the applicant has a first Right of Refusal on these azeas. The 6.37-acre Snyder Ranch house and farm buildings site would not be mined. The 8- to 10-acre surface facilities azea would be located east of Dry Creek and extend eastward onto a portion of Mining Area E. At the end of the mining operation, the surface facilities would be located westward to allow for the mining of the east end of Mining Area E. Surface facilities would include concrete batch plant, asphalt plant, concrete products manufacturing facilities, sand and gravel stockpiles, office trailer and portable shop. Access to the mining areas and surface facilities site would be from three existing ranch access roads off the Frontage Road along Interstate 70. Topsoil would be stockpiled in some locations along the south side of the mining azeas up to a height of 10 feet to create a visual barrier. The barrier would not involve a discharge of dredged or fill material in waters of the U.S. Mining Area A, the Renewable Resource Area, is located in a high water channel of the Colorado River. Mining would occur here only during periods of low water. The banks of the area will be left as a 3:1 slope. Approximal:ely 150 feet of landscape on the east end of the channel would be left as a barrier to prevent: the channel from filling up with water from the river. The downstream end would have adike/weir designed to let high flows through and keep low flows out so that mining can occur. In addition, the bank of the river, along the northwest side of the surface facilities, and the northeast side of Mining Area D would be stabilized with coarse rocks to prevent further erosion. After the initial mining of Area A, the frequency of mining in this area would be determined by the capacity of the Colorado River to deposit sand and gravel during periods of high flow. The applicant projects that mining will likely occur in Area A only once every 4 to 5 years and mining will not occur in this azea during the mid-February to mid-August period. The bottom of the pit in Area A will range in elevation from 5334 feet msl on the east end to 1329 feet msl on the west end. The Colorado River will continue to flow into this azea during periods of high flow. Water is expected to stabilize at the 5332-foot elevation during low water periods, creating a pond approximately 11 acres in size, which over time would likely fill in with sediment and small gravel. Mining Areas B, C, D and E aze expected to fill. with water following completion of mining, creating ponds with a water surface azea of approximately 101 acres. These ponds will have a slope of 3:1 to the water. All mine pits will be excavated to depths below the level of ground water and will, therefore, require dewatering for the lower elevations of the pits. Water will be pumped from the mine pits and disposed in on of the following ways: t) used to flood irrigate agricultural azeas not being mined, 2) pumped to detention ponds, or 3) pumped to mine pits at which mining has been completed. All dewatering will be conducted in accordance with an NPDES discharge permit from the State of Colorado.