2021-09-07_REVISION - M1973021 (4)

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Aggregate Industries, Morrison Quarry Amendment No.7 to Permit M-1973-021 FYZ Morrison,CO Item 8.0 Mined Areas Earthwork Once the site controls are installed, the grading plan for mined areas will be implemented. All areas will be appropriately marked to protect vegetation and structures to remain. The reclamation work areas will then be cleared and grubbed prior to excavation and backfilling. Available topsoil sources within the earthwork area will be stripped and appropriately stockpiled. Fill slopes in the upper highwall areas (southwestern corner) of the North Quarry will be placed and compacted to achieve a 2-foot cover sloped between 2H:1V and 20H:1V. Compaction will be performed with tracked equipment (D9 bulldozer) performing a minimum number of passes to achieve specified densities. The North Quarry additional fill area is estimated to require a minimum aggregate fill volume of 3,227 cubic yards if no additional byproduct material is used for fill. Fill slopes in the upper highwall areas of the South and West Quarries (above El. 7,000) will be placed and compacted to achieve 40-foot-high, 60-foot-wide benches, sloped 1H:1V, with 5- to 10-foot-wide benches and rockfall catchment berms every fourth bench. Compaction will be performed with tracked equipment (D9 bulldozer) performing a minimum number of passes to achieve specified densities. The South and West Quarries (above El. 7,000) are estimated to require aggregate fill volume of 286,815 cubic yards. Fill slopes in the lower highwall areas (below El. 7,000) will be placed and compacted to achieve 10-foot-high, 40-foot wide benches, sloped 1 OH:1V, with 5- to 10-foot-wide benches and rockfall catchment berms every fourth bench. Compaction will be performed with tracked equipment (D9 bulldozer) performing a minimum number of passes to achieve specified densities. The South Quarry (below El. 7,000) is estimated to require aggregate fill volume of 492,067 cubic yards. The average haul distance for the South and West Quarry Fill areas from the Central Quarry stockpile area is 1.15 miles (El. 7,000 bench). Final grading of all fill slopes, benches, crest areas, and toe areas will ensure that water is not allowed to pond on or adjacent to the fill slopes. Grading will be performed to the proposed slope gradients shown in the Grading Plan (Exhibit D— Mining Plan). Final subgrades will be developed using survey equipment from Item 4.0 and a CAT D9 bulldozer or CAT 349 excavator. Final grades, with organic material included, will be developed using an excavator to lightly spread out the material and prevent compaction. Item 9.0 Un-mined Areas Earthwork Areas disturbed within the Morrison Quarry but outside of mining boundaries will be reclaimed to blend with surrounding topography. This earthwork includes rough grading of approximately 32.5 acres. Areas to be reclaimed include haul roads, processing areas, and structure foundations. For areas where steeper slopes will remain, up to 0.33 acre of geosynthetic slope stabilization will be installed. Item 10.0 Soil Conditioning All reclamation areas within the Morrison Quarry will be reclaimed in a manner that allows for proposed post-mining land use. Reclamation areas will be backfilled as described in Items 8.0 September 2021 1 36