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Aggregate Industries, Morrison Quarry Amendment No. 7 to Permit M-1973-021 Morrison, CO October 2021 | 30 in Exhibit D.1. A temporary spur from this haul road will be installed and removed as needed for haul trucks to access the exposed benches of the South Quarry western highwall. Un-mined areas of the haul road outside of the mining boundary will be reclaimed consistent with adjacent reclamation. As benches become available for reclamation, overburden is placed on the bench surface and shaped and graded in preparation for placing topsoil and hydroseeding. The compacted overburden will slope upward from the access roads at a maximum of 2H:1V and a minimum of 20H:1V. The steeper (up to maximum 2H:1V) slopes will typically be located on the upper benches of the western quarry highwall, where a significant placement of overburden will be used to improve the visual appearance. Depending upon the amount of overburden that is available during reclamation, the slopes could be backfilled at a significantly shallower slope. As shown in Table E-1, a minimum amount of approximately 425,791 cubic yards of fill material would be needed at the end of Phase III to meet these final slope configurations. As noted in Exhibit F.3, reclamation above bench El. 7,000 will need to follow mining due to access constraints. Unsalable waste material to be used for fill is expected to be encountered in sillimanitic gneiss formations near the base of Phase III. Benches constructed at 60H:40V above El. 7,000 in Phase III of the South and West Quarries will require volumes of material shown in Table E-1. The highest un-reclaimed bench in the South Quarry is assumed to be at El. 7,400. The highest bench in the West Quarry is proposed to be at El. 7,320. As shown in Exhibit D – Mining Plan, the Phase III base of the South Quarry is proposed to be at approximately El. 6,500. Table E-1. South and West Quarry Phase III Fill Volumes Quarry Bench Elevation Range Acres Bench Length (feet per acre) Bench:Wall Configuration (H:V) Final Bench Slope (H:V) Total Fill (cubic yard) West 7,320–7,000 10.15 726 60:40 2:1 109,169 South 7,400–7,000 16.19 726 60:40 2:1 174,132 South 7,000–6,600 23.82 1,089 40:60 10:1 76,859 South 6,600 – 6,500 20.34 1,089 40:40 10:1 65,630 Total Phase III 425,791 Once the surface is prepared, topsoil and natural sediment control measures will be established. Where practical, a bulldozer will track at right angles to the slope to create microtopography in the surface of the topsoil. This has proven effective at Morrison Quarry in slowing erosion, retaining moisture, and catching grass seed. Additional sitework will create swales at right angles to the slope to create a more natural appearance. In some locations, unavoidable, localized, minor rock failures may occur on mined benches, which will serve to further break up the symmetry of mining and create more natural-looking slopes. Equipment used for backfilling will include a D-9-sized dozer, a 988 B-sized loader, and a 50-ton haul truck, or equivalent machinery.