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~LAFARG E <br />NORTH AMERICA <br />Construction Materials <br />7. On page 15, the permit text was inconsistent with Exhibit Fl. The applicant needs to <br />clarify, or correct these items so that they are consistent. <br />Lafazge has corrected the discrepancy, Exhibit F1 shows the correct phasing and configuration <br />and the permit text has been amended to reflect Exhibit F. Phase I Cell 1 will be the first silt <br />storage pond, totaling 6.3 acres. Phase I Ce112 will be 39.6 acres of water storage. <br />8. Much of the site is located in the 100 year flood plain of the South Platte River. <br />Wherever mining will occur within 400 feet of the river channel, cells will need to include <br />inflow and outflow channels, or other appropriate measures. The applicant must submit <br />engineering designs and updated maps to address this situation, where applicable. <br />Lafazge will not mine within 400 feet of the river channel without a bank stabilization analysis, <br />as necessitated by Stipulation No 1. Whether the cells will require inflow and outflow channels <br />will be addressed in that analysis. <br />9. The Reclamation Plan identifies five cells and existing pond that will be used for silt <br />storage and reclaimed as wetlands. Since these silt storage cells have the potential to act <br />as barriers to ground flow, the applicant must assess the potential impact and commit to <br />specifc mitigation measures. <br />Please see attached response prepazed by Donald Frick of Applegate Group, Inc. <br />10. The applicant needs to provide the basis for the statement on page 24 of 81, paragraph 3, <br />"No impact to the South Platte River is expected as a result of mining. " <br />No net impact to the South Platte River is expected as a result of mining. Please see attached <br />"Groundwater and Surface Water Evaluation Before During and After Riverbend Mining <br />Operations" prepazed by AMEC, which shows temporary impacts and mitigations to the South <br />Platte River as calculated with MODFLOW. <br />11. Rule 6.4.7(1) requires the operator to directly state if surface water or groundwater will <br />be affected by the mining operation. In accordance with Rule 6.4.7(2)b, the Division <br />requests that the applicant identify and characterize the aquifer to be mined in or <br />through. The Division also requests that the applicant define or predict the cone of <br />depression or shadow and mounding effect expected for nay areas to be dewatered and <br />dry mined or as a result of installation of clay liners. The cone of depression and <br />assessment of other effects should define, at a minimum, the horizontal and vertical <br />extent of expected impacts. <br />Please see enclosed "Groundwater and Surface Water Evaluation Before, During, and After Fort <br />Lupton / Riverbend Mining Operations" which defines the horizontal and vertical extent of <br />LAFARGE NORTH AMERICA INC. -Lafarge Aggregates, Concrete & Asphalt <br />10170 Church Ranch Way, Suite 200 Westminster, Colorado 80021 <br />Telephone: (303) 657-4000 Facsimile: (303) 657-4037 <br />