2004-11-09_REVISION - M2000016 (6)

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I' ~DDO' 0~~ l'"/'LJ~/ /i-y- D~/ EXHIBIT G Water Information General Mining at the Riverbend Pit will intercept shallow groundwater, which lies from three to six feet below the current ground level. Deeper bedrock aquifers that underlie the site will be unaffected by the mining operation because of the shallow depth of excavations. A Groundwater Monitoring Program is enclosed as a guideline for monitoring and mitigation measures. Upon completion of mining, 12 ponds will remain unsealed for recreational purposes, three ponds will be sealed for water storage, and five ponds will be filled with tailings. The open water ponds will cover an area of approximately 500 acres. The sealed ponds will cover an area of approximately 110 acres. Local surface water ponds, ditches, water courses, and tributazies are shown on the pre- mining map. The neazest water course is the South Platte River. No impact to the South Platte River is expected as a result of mining. Potential Water Resource Impacts The Riverbend Pit sand and gravel operation will have minimal impacts on the water resources in the azea. There aze 13 wells located within 600 feet of the proposed Riverbend Pit, however only two can potentially be impacted. The remaining 11 are either controlled by Lafarge or located on the other side of the South Platte River. Copies of the original Riverbend Gravel Well Permit Application and Substitute Water Supply Plan are enclosed; amendments to both documents to include additional acreage aze currently under draft. Discharge Permits The proposed mine will be dewatered and operated as a dry mine. Alluvial groundwater from pit dewatering will be dischazged into the South Platte River, in accordance with CDPS permit conditions. The estimated discharge rate during dewatering will range between 800 gallons/minute (gpm) and 5500 gpm, varying according to season and production rates. The applicant has an active certification authorization to discharge under the CDPS Industrial General Permit, number COG-500416, for the original 237 acres. The CDPS permit will be renewed and amended to include the entire 1,368 acres upon its expiration on September 30, 2007. Please see enclosed CDPS permit. Surface Water Management Please see the enclosed Stormwater Management Plan. Consumptive Water Use The total annual operational losses, due to the mining operation at the Riverbend Pit, aze projected over the life of mining according to [he enclosed Water Balance spreadsheet prepared by AMEC. OMG !12 Permil Page 24 oj87