2002-12-12_REVISION - M2001085 (7)

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Exhibit G - Water Information Exhibit G describes water resources of the project area, potential impacts to water resources attributable to the project, and the proposed project's water requirements, in accordance with Section 6.4.7 of Construction Materials Rule 6. Groundwater. The geology of western Adams County is characterized by a surface layer of unconsolidated sediments underlain by bedrock. The oldest bedrock formation is the Fox Hills sandstone, which is approximately 250 feet in thickness and underlies all of western Adams County. Overlying the Fox Hills sandstone is the Laramie formation, having a lower part predominantly of sandstone and an upper part composed largely of shale. Thickness of the Laramie formation decreases to the north along the South Platte River Basin but can be very thick, up to 600 feet, in the southwestern part of Adams County. The Arapahoe and Denver bedrock formations, which also vary dramatically in thickness, overlie the Laramie formation in southwestern Adams County. Well records from the State Engineer's Office of the Colorado Division of Water Resources show that deep wells in the vicinity of the proposed mining site (wells finished within bedrock that underlies the unconsolidated alluvial materials) are generally finished within the Arapahoe formation at depths from 220 to 500 feet. Unconsolidated alluvial sediments, consisting primarily of valley fill material and some terrace remnants, mantle the bedrock of the South Platte River Basin. This valley fill material fills contours on the surface of bedrock created by ancestral channels and is the important source of shallow groundwater in the region. It varies in thickness from 0 feet at the edge of the river valley to 125 feet in its thickest part. In the area of the proposed mining site, thickness of this unconsolidated fill material is between 35 and 65 feet, based on soil borings performed in July, 2002, with the water table at five to twenty feet below the ground surface. Well records from the State Engineer's Office of the Colorado Division of Water Resources show that most shallow wells in the vicinity of the proposed mining site are finished to depths from 20 to 50 feet; however records also indicate that a few wells are finished near 90 feet below the ground surface. The ultimate source of all groundwater in the South Platte River Basin is precipitation. Water in the saturated zone of the unconsolidated valley fill material percolates laterally, generally in a northwesterly direction, ultimately discharging to the South Platte River or at the surface through wells, seeps, and springs, or by evapotranspiration. Shallow groundwater is recharged principally by subsurface inflow through unconsolidated rock materials, by seepage from streams, unlined reservoirs and ditches, and irrigated tracts, and by infiltration of precipitation. Based on a depth to the water table of 20 feet and depth to bedrock being 35 to 65 feet, the saturated thickness of shallow groundwater in the area of the proposed mining site is 15 to 45 feet. Well Information. The proposed mining site occupies most of the SW quarter of the SW quarter of Section 35, T 1 S, R 67 W. Records of registered wells on this quarter/quarter section and on surrounding land have been researched at the State Engineer's Office to identify wells within 600 feet of the proposed mining site. The State Application to Amend -14- 124`h Estates Partners DMG 112 Reclamation Permit No. M-2001-085 124`h Estates Sand and Gravel Mine Prepared by Scott Keen, December 2002 Henderson, Colorado