2012-09-06_REVISION - M2008070 (25)

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Design and Operations Plan October 24, 2011 Western Gravel E & P Waste Disposal Facility Page 46 of 51 5.0 LANDFILL CLOSURE AND RECLAMATION The facility will be closed in accordance with the Regulations and i ndividual waste cells closed when filled to capacity. As the final lift is completed, final cover will be placed as discussed in Section 3.4.9. Cell closure activities must be observed by a qualified engineer and documented. For documentation purposes, the cover system must be surveyed following installation of certain components. Following cell closure completion, a CQA report shall be prepared by a Colorado register Professional Engineer, certified, stamped, and submitted to CDPHE. Reclamation activities presented below will be conducted similar to the approved WRC Gravel Pit SUP. 5.1 CLOSURE SCHEDULE When each cell capacity is reached, closure of the particular cell will begin. Initiation of each cell closure will begin within 30 days of reaching final waste placement grades and be complet ed within 180 days of cell closure activities commencement. A 60 -day prior notice will be provided to CDPHE, Rio Blanco County, and the public regarding fmal closure of the entire landfill facility. The public will be notified in the form of signage p laced at the landfill entrance. The property deed shall be amended to note use of the property as a solid waste landfill. Following closure, the property shall remain rangeland zoned agricultural. 5.2 GRADING AND SEEDBED PREPARATION All final grades and slopes of cells will range from 4:1 to 6:1 and remaining retention pond slopes will be 3:1. In order to minimize erosion, run -on diversion channels will remain until Phase 2 mining and reclamation activities are completed. Run -off diversion channels associated with the retention ponds will remain. Remaining retention ponds are anticipated to potentially benefit livestock and wildlife. Flat areas and/or depressions in cells where water could pond will not remain following final grading. The topsoil layer shall be placed immediately prior to seeding and be able to sustain vegetation specified below. Compacted soil shall be roughened prior to topsoil placement in order to provide adequate binding with underlying soil. Topsoil shall be spread to a 6 -inch depth, tilled, and firmed in order to provide an adequate seedbed. 5.3 SEEDING Seeding will be conducted during the fall after approximately October 15 and prior to freezing soils. Seed will be drilled using a grass drill equipped with double disk openers and packer wheels. Drilling will follow grading contours. Drilling perpendicular to contours will be avoided in order to minimize erosion potential. A %2 -inch planting depth will be used. In the event that seed is broadcast, the seeding rate will be doubled. In addition, the seeded area will require harrowing or dragging in order to properly integrate the seed into soil. The previously BOCC approved seed mix will be used as summarized below. • Western Wheatgrass (species), Arriba (Variety), 3.2 (Pounds of Pure Live Seed [PLS] Per Acre). • Thickspike Wheatgrass, Critana, 2.2 PLS /Acre. • Streambank Wheatgrass, Siberian, 2.2 PLS /Acre. • Russian Wildrye, Vinal, 2.0 PLS /Acre. • Crested Wheatgrass, Ephriam, 2.0 PLS /Acre. Total pounds PLS /Acre = 11.6 NWCC, Inc.