2020-12-08_REVISION - M2008078 (23)

Home Browse Search

EXHIBIT D Mining Plan Mining Limits Prowers Aggregate operators, LLC currently operates a gravel mine in the northeast % and the northeast %4 of the northwest % of Section 33, and the south '/2 of the southeast %a of Section 28, Township 22 South, Range 46 West of the Sixth Prime Meridian, in Prowers County, Colorado. This amendment adds areas to the permit area to the west and east of the current permit area for product staging and additional mined area, and modifies the limits of the current permit boundary. The site lies approximately '/2 mile east of the City of Lamar, and approximately %4 mile north of State Highway 50. Access to the site is located off of Prowers County Road HH.5. The dominant land use surrounding the property is agricultural. Aggregate processing plants are located within the mining area as shown on the Mining Plan Map. The area will contain stockpiles and portable equipment as necessary to support the plant operations. The permit boundary will encompass approximately 1,310.64 acres with approximately 1,082.5 acres being mined. The remaining area will consist of setbacks, road and utility right-of-ways, equipment storage, product processing areas, product storage and loadout areas, and plant site access. Various setbacks from adjacent roads and man-made structures will be maintained as mining occurs. See Exhibit C, Mining Plan Map, and the Slope Stability Report for the mining limit configuration and information on setbacks and their locations. Products Sand and gravel will be the primary product produced from the West Farm Pit site. The principal intended use for the sand and gravel is for road base and construction aggregates. Subsurface drilling and testing has verified that the West Farm Pit property contains a significant commercial deposit of sand and gravel. The depth of the overburden ranges from 2 to 27 feet. The thickness of the aggregate material ranges from 7 to 60 feet. The overall depth to bedrock ranges from 22 to 67 feet. See Exhibit I, Soils Information, for detailed data on the nature, depth, and thickness of the soil strata present in the property area. Mining Methods The deposit will be dry mined. A slurry wall liner will be installed prior to mining commencing. Dewatering trenches will be excavated around inside of the perimeter of the slurry wall for each mining phase after the slurry wall is installed in order to dewater to a depth where mining can commence. The depth of the ditches will vary as the mining progresses deeper into the alluvium in order to maintain the groundwater level below the active mining bottom surface, and therefore minimize the exposed groundwater surface area. The dewatering ditches and process water will flow through a series of sediment settling ponds, from which the water will be discharged into a farm ditch, and then discharged into the Arkansas River. 1-' JmT Consulting,Inc. Prowers Aggregate Operators, LLC. West Farm Pit—M-2008-078 DRMS 112 Permit Amendment Application