2020-08-09_PERMIT FILE - M2020041

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Peak Ranch Resource August 5, 2020 1.2 Mining Phases The mining operation will be conducted in two phases. Phase 1 is divided into two sections, Phase 1 North (12.6 acres) and Phase 1 South (33.2 acres), as shown on Exhibit C, Sheet C-2A. This is due to a Town of Breckenridge drainage easement that bisects the site. The plan is to mine Phase 1 North prior to mining Phase 1 South. All of Phase 1 will be dry mined therefore Phase 1 mining will stop about two feet above the typical seasonal high-water table. The mine design assumes that the exposed water table in Phase 1 North will be approximately seven feet below existing grade and that it will be deeper in Phase 1 South. Exhibit G discusses groundwater in detail. If groundwater is encountered at a depth that is shallower than expected, the area will be backfilled to two feet above the discovered water table. The plan is to concurrently mine and reclaim Phase 1 North before mining Phase 1 South; however, activity is likely to occur in Phase 1 South prior to completion of Phase 1 North. An approved Substitute Water Supply Plan (SWSP)will be in place prior to beginning Phase 1,to replace out-of-priority depletions associated with on-site water use needed for dust suppression. During Phase 1 operations, this is the only anticipated water demand. An augmentation pond will be constructed in Phase 1 North to meet the needs of the site during mining operations. Phase 2 of the project will entail excavating an area within the center of Phase 1 South to a final depth of roughly 55 feet, as shown on Exhibit C, Sheet C-213. This phase will be wet mined utilizing a dragline or similar pieces of equipment. No pumping of groundwater will take place during any phase of mining.As the material is removed, it will be placed in a temporary stockpile above the water table to allow it to drain before it is loaded onto trucks for shipping offsite. Extraction of the material is expected to begin on the south side of the Phase 2 area and move north. Once the material has been removed from Phase 2, the result will be a 26- acre open water pond. Prior to exposing ground water to evaporation in connection with Phase 2 mining and the 26-acre open water pond, a Water Court approved augmentation plan will be in place to cover all out-of-priority depletions (including post-mining), or the applicant will otherwise demonstrate to the DRMS that all out-of-priority depletions will be replaced to the stream system to prevent injury to other water rights through an acceptable approach.Approval of an augmentation plan is a multi-year process. Therefore, Peak Materials hereby commits to incorporating the augmentation plan into the 112 Reclamation Permit via a future Technical Revision submittal and approval prior to exposing any groundwater in Phase 2 of the mining plan. See Exhibit G for a more detailed discussion of water related matters. In the unlikely event that it becomes infeasible for Peak Materials to obtain approval of an acceptable augmentation plan to support Phase 2 mining and a 26-acre open water pond, Peak Materials would simply reclaim the Phase 2 surface. Topsoil to reclaim this area would come from the screening berms that will be constructed on the north and west edges of the site. The area would be revegetated in the same manner as the side slopes of Phase 1 South. Exhibit C, Sheet C-2C is provided to more clearly show and explain planned setbacks from the edge of mining,the stormwater control plan for the site, and groundwater details for clarity and ease of review. All activities will take place within an overall disturbance area of 54 acres. This is comprised of Phase 1 North, Phase 1 South,the access road from Highway 9 into the site, and the areas being disturbed to construct the screening berms. The overall disturbance area reflects the extent of activity on site, not the peak of simultaneous disturbance. Since contemporaneous reclamation techniques will be followed,the overall disturbance area will never exist simultaneously. The peak simultaneous, or active, disturbance will be about 26 acres and would occur right before Peak Materials is ready to begin Phase 2 mining. 1.3 Equipment Table D-1 shows the type of equipment that will be used for the operations of this site. Once operations are complete, all equipment will be removed from the site. (;n,IL.—,ki and,lsurcWo,I'LL( D-2 O TETRA TECH