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Second Submittal <br /> 2.0 BACKGROUND <br /> Sand and gravel mining has occurred along the Cache La Poudre River corridor for decades. <br /> As the alluvial deposits were excavated and processed into construction materials, the <br /> gravel pit sites were depleted of sand and gravel and reclaimed for residential, agricultural, <br /> wildlife habitat, or water storage uses. In the reclamation processes, groundwater <br /> conditions reverted to conditions similar to the pre-mining status. Figure 2 shows the <br /> locations of local sand and gravel mines that have accessed Poudre River alluvium; the <br /> Colorado Department of Natural Resources, Division of Reclamation Mining and Safety <br /> (DRMS) maintains a map of sand and gravel sites (CDRMS, 2017). Following cessation <br /> of mining, many pits have beon(Teclaimed as lakes, or reverted to open space used for <br /> grazing or wildlife habitat. <br /> 2.1 Geologic Setting <br /> The Project lies at the western margin of the Denver-Julesburg Basin with the Northern <br /> Rocky Mountain Front Range uplift to the west. The Project terrain is characterized by <br /> low relief fields and pasture. ' To;the west-northwest of the Project lies the Bellvue Dome <br /> anticline, which has been breftched by erosion exposing the Permian-Triassic age Lykins <br /> Formation at its core (Hagardorn, 2001). Resistant beds of Permian Lyons, Satanka, and <br /> Ingleside Formations cap the top of the ridge forming the east half of the dome. <br /> The Project overlies unconsolidated alluvial deposits of Quaternary age deposited during <br /> natural meandering of the ancestral Cache la Poudre River system. The alluvial sands and <br /> gravel were eroded from the Rocky Mountains to the west and deposited along broad areas <br /> of the river valley. Alluvial deposits underlying the Project can be characterized as poorly <br /> sorted (well graded) granite-sourced clays, silts, sands, gravel and cobbles. These alluvial <br /> deposits are exposed at the ground surface and extend approximately 1,500 feet to the north <br /> of the Project, and for some distance south across the current Cache la Poudre River <br /> floodplain. In the vicinity of the Project, the alluvium is deposited on an erosional contact <br /> with the Cretaceous Pierre Shale. The Pierre Shale is relatively impermeable and <br /> considered a bedrock aquiclude when evaluating alluvial-bedrock groundwater interactions. <br /> Loveland Ready-Mix Concrete 4 Telesto Solutions,Inc. <br /> zoiKoi iz nawmv,may_zni��ummnal d— January 2018 <br />