2014-11-25_REVISION - M1979191 (21)

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Shaping of the reservoir bottom should not encroach within 25 feet of the toe of the slope liner and reservoir floor excavation slopes, if necessary, should not exceed a slope of 6:1. The reservoirs should be graded to the bedrock low point, as noted in the construction plans. The area between Phase 3 and Phase 2 and 5 requires backfilling as a result of historical site stripping to allow for increased storage in the Pond 3, and create a more uniform roadway. The existing material was stripped to an approximate elevation of 4804 feet, resulting in a limited storage capacity of approximately 9 acre -feet, with a normal high water surface elevation (NHWL) of 4802 feet. Backfilling the area will increase water storage in Pond 3 to approximately 94 acre -feet, with a NHWL of 4808 feet. The roadway backfill area has been designed at an elevation of 4810 feet, transitioning into Pond 3 slope liner and into Phase 2. Figure F -1 shows the configuration of the slope liners for the Ditullio property. Figure F -2 (provided by others) shows the slope liners to be constructed in the mined -out phase in the Veldman Property. Much of the Three Bells property lies within the Cache la Poudre River flood plain. Each reservoir will have inlet- outlet structures installed during construction of the slope liners to protect from flood damage. Construction of reservoirs will comply with applicable Larimer County floodplain development regulations. Phase 5 and portions of Phase 4 are to be backfilled and re- vegetated. Phase 5 and portions of Phase 4 will not be reclaimed as below -grade reservoirs with slope liners, but may later become a residential development in accordance with applicable Larimer County zoning laws. Approximately 9.2 acres within the mine limits of these phases has been allocated to developing reclaimed areas into potential residential housing via backfilling the areas with overburden, topsoil, and spoils developed during pit reclamation. The detailed revegetation plan is presented in Section 5.4. Phase 2 will be utilized for wash fines during the Ditullio mining operations, and will be reclaimed to an unlined open water pond. Areas adjacent to and in close proximity (1 mile) to the Three Bells Mine are zoned as incorporated city in Windsor, Colorado. This current land use is similar in nature to the proposed post - mining land use for Phase 5 and the Veldman Property, including residential neighborhoods and farming use. The Veldman pond slope liners are designed to meet SEO seepage requirements. The slope liners extend to the top of the pit highwall, which results in the construction of slope liner above the high waterline. This is done to minimize groundwater seepage into the pit. A minimum freeboard of 2 feet has been assumed.