2024-11-04_PERMIT FILE - M2024056 (6)

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The sand and gravel deposit, averaging 36 feet in thickness, will be mined progressively from north to south in each mining area. Mining will take place across three areas as shown on Map C-2. Groundwater is anticipated to be found 6-feet below the natural topography. Mining and reclamation will occur concurrently to minimize overall disturbance. There is ample on-site topsoil and overburden for successful reclamation, transforming the site into water storage ponds surrounded by rangeland. The reclamation process will involve backfilling, regrading, topsoiling, and revegetation. Some or all of the water storage ponds may be filled based on market demands for inert fill disposal. Mining will extend to the bottom of the gravel deposit, maintaining final mining slopes at 1.5H:1 V along the perimeter. The active highwall will have a near-vertical slope, progressing halfway down the final mining slope to enable the dozer to knock down the remaining highwall, creating the completed mining slope. Slopes will then be backfilled with sand or overburden to achieve the reclaimed 3H:1 V slopes, with specific slope details available on Map C-3 cross sections. Mining setbacks are shown on Map C-2. No mining will take place within 100-ft of the South Platte River. See Exhibit G for details on surface water protection. No blasting will occur at the Evans Mining Resource. If refuse, acid, or toxic materials are unexpectedly encountered, these materials will be removed from the site and disposed of appropriately. 2. Mining Timetable Mining operations at the Evans Mining Resource are expected to take approximately 21 years to complete, based on an annual average production of 300,000 tons. Actual production rates will fluctuate based on market conditions. An approximate mining timetable based on this production and the phased mining plan is shown in Table D-2. Table D-2 Mining Timetable Description Time Required Construction of slurry wall A. 2 months Initial stripping of Phase 2. 1 month Mine and reclaim Phase 2 according to 4.5 years approved plans.Reclamation occurs as mining has reached its maximum extents in an area. Construction of slurry wall B. 2 months Initial stripping of Phase 3/4. 1 month Mine and reclaim Phase 3&4 according to 8 years approved plans.Reclamation occurs as mining has reached its maximum extents in an area. Stripping of Phase 4 occurs towards the end of mining in Phase 3. Initial stripping of Phase 5/6. 2 months Evans Mining Resource October 2024 D-2 Lewicki&Associates