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Lyons Quarry ��� <br /> 112d Reclamation Permit Operations <br /> Technical Revision <br /> As a first step toward final reclamation, prior to mobilization, an updated topographical survey of the <br /> site will be conducted to establish the 100 and 500-year floodplains as well as site perimeters and <br /> slope staking. An inventory will be taken of existing structures, utilities, and remaining equipment to <br /> be demobilized and/or disposed of. A project safety plan will be developed to be consistent with <br /> applicable OSHA and MSHA requirements prior to initiation of field activities. Due to the September <br /> 2013 flooding, site conditions have changed since the mining activities ceased in the mid-2000s and <br /> utility locates will be conducted prior to any earthwork. <br /> Erosion control Best Management Practices (BMPs) and dust control measures will be established <br /> prior to any site grading to restrict sediment transport from the site and control dust generation <br /> during construction activities. BMPs will be established in accordance with Boulder County Storm <br /> Drainage Criteria Manual that requires the design of BMPs be consistent with the guidance in the <br /> Colorado Department of Transportation (CDOT) Erosion Control and Stormwater Quality Guide <br /> (CDOT, 2006) or Urban Drainage and Flood Control District (UDFCD), Urban Storm Drainage <br /> Criteria Manual Volume 3 (UDFCD, 2016). <br /> Appropriate measures will be taken to ensure areas outside of the affected land are protected and <br /> any refuse associated with the flooded infrastructure and equipment, or any identified hazardous <br /> materials, are disposed of properly. At this time there are no known hazardous materials on site and <br /> the construction documents will include specifications that require the contractor to stop work <br /> immediately and notify Aggregate Industries and the State if any hazardous materials are <br /> encountered. <br /> Once the site controls are installed, the grading plan will be implemented. As shown on Section A on <br /> the Site Grading Plan, Attachment B, all reclamation slopes in the overburden sedimentary rock will <br /> to be cut to an overall slope angle of 33 degrees, 1.5H:1 V slopes, using drill and blast methods. The <br /> pit highwall areas will be backfilled using 50-foot-high, benches, sloped 2H:1V, with 15 foot wide <br /> bench widths, in accordance with the stable cut and fill slopes described in the Rule 6.5 <br /> Geotechnical Stability Report, Attachment E. All backfill will be moistened, placed and compacted to <br /> achieve adequate density for stability. The revised Site Grading Plan is shown in Attachment B. The <br /> slopes shown on the Site Grading Plan are verified as meeting the geotechnical specifications of the <br /> Geotechnical Stability Report in a letter signed and sealed by a qualified Colorado registered <br /> Professional Engineer, Attachment F. <br /> Fill will be placed in horizontal lifts not exceeding 2 to 3 feet in thickness, depending of the fill <br /> materials. Compaction requirements will depend on the lift thickness and the equipment used, but <br /> adequate compaction should be achievable by tracking with a dozer or with the routing of <br /> construction equipment traffic, provided material characteristics, moisture content and lift thickness <br /> are appropriate. Final grading of all fill slopes, benches, crest areas, and toe areas should ensure <br /> that water is not allowed to pond on or adjacent to the fill slopes. Any remaining prospect pits, drill or <br /> auger holes or portal openings will be closed according to DRMS regulations. <br /> Reclamation areas have been developed based on a site slope analysis. Areas identified with <br /> slopes steeper than 1.5H:1 V will be too steep to effectively apply soil amendments and produce a <br /> vegetative cover. These slopes comprise about 4.8 acres of Area 1 and will be covered with a 2-foot <br /> thick layer of talus riprap (D50 = 12 to 14 inches) and compacted using an excavator bucket. Areas <br /> flatter than 1.5H:1 V will be reclaimed using types of reclamation appropriate for the final grades and <br /> soil conditions present. These areas will be backfilled and compacted as described above then <br /> covered with a layer of growth medium material comprised of a blend of available onsite topsoil, the <br /> soil materials developed from excavation and breakdown of the weathered fine-grained sedimentary <br /> November 2016 1 4 <br />