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Lyons Quarry �`` <br /> 112d Reclamation Permit Operations 77` <br /> Technical Revision <br /> Proposed <br /> Swale Berm <br /> Alternative Catchment <br /> Quarry 1 Rockfalll Berrn Alignment <br /> Catchment Basin 1(18 It high with 11 side slopes) <br /> Access Restriction <br /> Fencing <br /> Catchment Berm <br /> Alignment 1 Quarry 1 <br /> (12 feet high with 1:1 / \ <br /> side slopes) By / <br /> s <br /> B ��. <br /> f, <br /> NW Dacite A <br /> Wall NE Dacite <br /> � Wall <br /> Quarry 2 r' <br /> (to be bacWilled) + - ,,..-••"` <br /> Dacite'Sandstone <br /> \ J Contact <br /> (2:1 grading above this line) <br /> Figure 2 — Rockfall Catchment Basins and Berms, (Attachment E-2, Figure 1) <br /> The Fountain Formation sandstone was modeled as excavated to a 2H:1V slope as discussed <br /> above; however, for conservatism the 20-foot wide bench at the sandstone/dacite contact was not <br /> included in the evaluation. The northeast-facing dacite highwall was modeled as-is based on the <br /> updated topographic survey conducted in September 2020 by Aggregate Industries. Section A, <br /> shown on Figure 6, was selected as the most critical section for the highwall and used to generate <br /> the slope configuration. Using the current condition of the slope is conservative because the scaling <br /> work discussed above will reclaim some of the benches that exist in the dacite that were formed <br /> during the quarrying process, which will provide rockfall containment on the highwall until they fill <br /> with collected material. <br /> The results of the evaluation indicate that along the critical Section A, either a 170-foot long run-out <br /> area with no berm, or a 30-foot long run-out area with a 9-foot high catchment berm, is necessary to <br /> catch 100% of all rock sizes modeled. Spherical sandstone blocks up to 12 feet in diameter were <br /> March 2021 1 11 <br />