Laserfiche WebLink
prevent erosion. Prior to the mining of new cells, a dewatering trench will be constructed <br />around portions of the perimeters. A sump hole will be created at the lowest point of the <br />dewatering trenches. The sump holes and dewatering trenches will allow sediment to settle <br />before the water is pumped to the South Platte River and Big Dry Creek using a <br />groundwater discharge pump in accordance with Colorado/NPDES discharge permit <br />regulations. If agreements are obtained, water may also be discharged in the Lupton <br />Bottom Ditch and Brighton Ditch. Pipes transporting the water from the mine will <br />discharge the dewatering water directly into the South Platte River or identified waterway. <br />Pipes will be slotted along areas with a high density of cottonwood trees to minimize <br />impacts of dewatering and preserve mature vegetation. Water may also be pumped into <br />adjoining cells. <br />When the alluvium is sufficiently dry, front-end loaders will excavate the material and <br />deposit it on conveyors. The mining face will be nearly vertical to ''/Z:l slope. The <br />conveyors will transport the material to be processed at the Plant Site azea, located in Phase <br />The Plant Site area contains the crushing, screening and washing equipment used for the <br />processing of the raw materials. The processed materials will be stockpiled for use on-site <br />at the concrete and asphalt plants and delivered off-site for commercial and government <br />projects. The processing area will also include a concrete casting facility where concrete <br />forms will be made for construction projects and a recycling plant. In addition, materials <br />used in the asphalt and concrete batching process will be imported to the site. The import <br />materials may include but is not limited to: coazse aggregate, petroleum and cement. The <br />Plant Site area will be approximately 40 acres and will be the last phase mined. Lafarge is <br />in the process of finalizing a site plan for the plant site and will provide a detailed <br />enlargement sheet as an addition to these drawings. The entrance to the plant site will have <br />asphalt from the scale house to Weld County Road 6 and screening of the boneyard. <br />Technical advice was provided by: Office of the State Engineer, U.S. Soil Conservation <br />Service, Colorado Division of Wildlife, ERO Resources Corporation, Tetra Tech - RMC, <br />Inc., Colorado Division of Minerals and Geology, U.S. Army Corps of Engineers, U.S. <br />Fish and Wildlife Service, and the U.S. Environmental Protection Agency. <br />Mine Schedule (addresses USR Questionnaire, Items #l.e, f, g; #8.c,i,m) <br />The Riverbend Operation will process approximately 2 million tons of aggregate per year <br />and mine approximately 25 - 30 acres per year. At this rate, Lafarge anticipates mining and <br />reclaiming the Site in 34 years; however, the rate of mining and overall life of mine is <br />dependent upon demand and market conditions. <br />The mine phases and associated mine cells are depicted on the Mine Plan. Mining in <br />phases will limit the area of disturbance at any one time. The phases depicted on the Mine <br />Plan are used to indicate the direction of mining. These phases are neither representative of <br />the maximum area of disturbance nor do they limit disturbance to a particular phase. <br />Generally, Lafarge believes the mine will progress according to the following time table: <br />Lafarge Wesl, lnc.. -Riverbend <br />{Veld County USR Permil <br />Page !3 of 4t <br />