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// PAGE 7 <br />EXHIBIT L <br /> <br /> <br />Raptor Materials, LLC Cogburn Sand, Gravel, and Reservoir Project February 2025 <br />A Regular Impact (112) Construction Permit Application – Colorado Division of Reclamation Mining and Safety, Office of Mined Land Reclamation <br /> <br />Figure 2. Typical Fully Reclaimed Liner and Backfill Construction for Wall Depths Greater than 30 ft <br /> <br />Haul distances from stockpiled backfill materials are expected to be very short, with temporary stockpiles <br />strategically placed near areas that will require regrading as excavation advances. Unit costs were taken <br />from the recent DRMS-provided P124 Two Rivers (M2022-013) cost estimate. Calculations for the individual <br />lining component costs are provided in Table 5 below. <br />Table 7. Reclamation Liner Installation Cost Estimate <br />Activity Initial Vol [cu.yd] Swell/Compaction Factor Loose/Compacted Vol [cu.yd] Unit Cost [$/cu.yd] Total Job Cost <br />Grade 5,818 1.215 7,069 $0.505 $3,570 <br />Haul 17,754 N/A 17,754 $1.073 $19,050 <br />Mix 8,877 1.215 10,785 $0.248 $2,675 <br />Compact 17,754 0.91 16,156 $0.145 $2,343 <br />Total Liner Cost: $27,637 <br />Backfill <br /> <br />At the 5-year mark, liner will have been keyed into the base of the Pit P125B side walls at depths greater than <br />30 feet and installed up to 25 feet bgs. Pit P125_S1 will be completely backfilled and Pit P125A will be <br />regraded, lined, and backfilled. Within Pit P125B, only walls with depths greater than 30 ft bgs will have been <br />backfilled at 3H:1V from pit bottom up to 25 ft bgs, as detailed in Exhibit E – Reclamation Plan. Backfill was <br />separated into two stages for the purposes of cost estimation: hauling subsoil from source(s) to Pit P125B to <br />grade over the liner, and grading the subsoil. <br /> <br />Surfaces were created for the 5-year and reclaimed conditions in a 3D CAD program for Pit P125B; backfill <br />volume required for reclamation was determined to be the difference between these two surface volumes. <br /> <br />Backfill will be achieved using a combination of imported material from nearby sites P115 Kurtz (M1999-006) <br />and P122 Bearson (M2015-003), which will be strategically staged for backfill use as reclamation progresses,