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Rifie Grave Fl � #1 January 2()_>3 <br /> continues to remove material. The pond water will be in direct contact with the water <br /> table of the Colorado River via lateral migration through the underlying permeable <br /> gravels. Excavated material will be piled on the edge of the pond for approximately <br /> 24 hours, to allow drainage of free water from the material back into the pond. <br /> • Sideload dump trucks will travel to the pond edge and will be loaded with the dried <br /> material on a daily basis. The dump trucks will transport the dried material from the <br /> active excavation area to the processing facility (a distance of 800 -1,500 feet <br /> depending upon the mining location), where the material will be stockpiled for <br /> washing, processing, and subsequent sale. <br /> • Any agricultural return flows in the tailwater ditch, which are estimated at <2 cubic <br /> feet per second (cfs) during peak irrigation season, will be discharged into the pond, <br /> mixed with the alluvial aquifer, and migrate laterally through the permeable gravels <br /> into the larger Colorado River water table. Given the minimal flows in the ditch, the <br /> large size of the pond (estimated at approximately 6 acres within one year), and the <br /> highly permeable nature of the gravel, the agricultural return flows will have a <br /> negligible effect on water levels in the pond. As excavation proceeds, the tailwater <br /> ditch will be subsumed into the expanding pond boundaries, until under final <br /> conditions (Figure 11, Exhibit C6) the discharge point of the ditch to the pond will be <br /> located where the ditch enters the eastern boundary of the property. <br /> • Reclamation activity will proceed in concert with the excavation (see Figure 9, <br /> Exhibit C4 through Figure 11, Exhibit C6). A six-foot wide fringe of 5:1 slope will <br /> be left at the inner edge of the perimeter berm and planted with wetland reclamation <br /> species. The intention is for the six-foot wide fringe to be nearly inundated during <br /> high-water periods as the water table rises, and then to be progressively exposed as <br /> the water table drops during the growing season. The remainder of the pit slope to <br /> the bottom of the pond will be approximately 3:1, not to exceed 2:1. Note that this <br /> reclamation effort follows local Garfield County guidelines and standards (LUC <br /> Section 7-1002.H). Formal wetland mitigation per USACE standards is not required, <br /> as no impacts to wetlands are proposed. <br /> 5.2.3.2 Water Diversions and Impoundments <br /> As previously described, the Last Chance Ditch tailwater channel, which currently terminates <br /> on the property west of the Affected Lands and Permitted Area, will be incorporated into the <br /> excavated pond where aggregate is being removed. The irrigation return flows in the ditch <br /> will be mixed with the alluvial groundwater that fills the pond, and the water will continue to <br /> migrate laterally through the underlying permeable gravels to reach the Colorado River. The <br /> exact point where the tailwater channel enters the pond will migrate as the excavated <br /> boundaries of the pond expand; under final conditions the Last Chance Ditch tailwater <br /> channel will discharge directly into the pond at the point where the ditch enters the property <br /> on the eastern boundary. <br /> 5.2.3.3 Water Handling and Dewatering <br /> Scott will comply with the State Engineer Office's (SEO) rules and regulations regarding any <br /> water depletions that may occur during mining operations from water lost with mined <br /> aggregate and water used for dust suppression. <br /> 31 <br />