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Aggregate Industries, Morrison Quarry <br /> Amendment No.7 to Permit M-1973-021 FYZ <br /> Morrison,CO <br /> Grading <br /> Grading of fill material will be performed on all benches meeting the requirement approved in <br /> Section 5.03 of AM05. In general, fill material will be graded to slopes appropriate to the soil <br /> type and terrain of the area. Slopes will be graded to minimize erosion and to facilitate <br /> revegetation. Depending on the stability of the rock face encountered, some portions of the high <br /> walls may remain exposed, providing nesting habitat for bird species. The graded slopes will <br /> vary between 20H:1V and 1H:1V along the reclaimed benches. Final grading will create a <br /> surface that is variable and somewhat irregular to give a more natural appearance, while <br /> effectively conveying drainage. <br /> As recommended in Appendix 1, Rule 6.5 Geotechnical Stability Exhibit, in South and West <br /> Quarry benches above El. 7,000 where topsoil backfilling and revegetation is permit-required, <br /> several rockfall benches should be left open for rockfill catchment. The Geotechnical Stability <br /> Exhibit recommends this consisting of a 5- to 10-foot zone free of fill material every three to four <br /> benches. This material-free zone would reduce the potential for isolated rockfall from traveling <br /> down slope and propagating down to the active mine areas, reducing the risk to mine personnel <br /> and infrastructure. These rockfall berms would remain in place following reclamation for the <br /> protection of wildlife and maintenance personnel accessing the former highwall areas. The <br /> berms serve a dual purpose as rockfall catchment and a berm against the outboard (downhill) <br /> side of access routes crossing the quarry slopes. Quarterly scaling of final slopes below El. <br /> 7,000 will reduce the potential for overhead hazards. Machine scaling will identify instability in <br /> rocks within the highwall and will remove the hazard utilizing various techniques under a <br /> controlled environment. Prior to final grading and during the vegetation establishment period, <br /> catchment berm areas would be cleared of accumulated rockfall to allow for vehicle access. <br /> A D-7- or D-9-sized bulldozer will be used for grading. After the processing plant has been <br /> removed, the exposed ground will be ripped, graded, and scarified prior to topsoil placement <br /> and revegetation. <br /> Structure Removal <br /> Permanent structures to remain onsite following reclamation will include stormwater drainage <br /> infrastructure, perimeter barbed wire fencing, maintenance access roads, a holding tank east of <br /> Reservoir Site II, and a utility shed south of Reservoir Site II. These features are shown on <br /> Exhibit FA. The holding tank and utility shed are considered necessary for post-mining use and <br /> continued maintenance of Reservoir Site II by the Town of Morrison. <br /> All other structures not shown in Exhibit FA through Exhibit F.3 will be dismantled and removed <br /> from the site prior to final grading and reclamation. These include, but are not limited to, the <br /> following structures: <br /> • Processing Area Equipment (conveyors, crushers, etc.) <br /> • Mine Administration Offices <br /> • Riprap Plant <br /> September 2021 1 30 <br />