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There are no jurisdictional wetlands, riparian areas or waters of the United States within the permit <br />area. The pond to the south and a long narrow slew immediately west of the permit are surface water <br />areas near the permit, however, these will also not be affected by the operation. <br />The existing site is heavily grazed, since horses are permanently kept in relatively small areas and <br />some erosion from runoff occurs as a result although the flat nature of the site serves to minimize <br />erosion.. The 100 year 24 hour rainfall event for this area is only 1.8 inches. <br />There are two USGS gaging stations in the area, one on the Colorado River near Fruita (1.5 miles <br />downstream of the permit azea) and one on Adobe Creek. Data for the Colorado River station is <br />given in Appendix C. Although the River data is primarily a two year period, 1994 and 1995, there <br />is general consistency and no reason to believe that the quality has changes significantly since 1995. <br />The pH of the River is fairly constant at 8.0. Total dissolved solids range from 429-898 mg/liter de- <br />pending upon the flow quantities. Overall, the water could be characterized as average in dissolved <br />solids and the pH is slightly above neutral, which is typical of most western U.S. waters. The water <br />has typical high calcium, magnesium and sulfate dissolved ions. During low flow periods, the river <br />height is from 2.0 feet to 3.5 feet. During high flow periods, the height of flow is from 3.5 to 7.0 <br />feet. <br />The River data does not report suspended solids although it is well known that the area sees levels <br />ranging from approximately 100 mglliter to 3300 mglliter, demonstrating the wide variability of the <br />sediment load in the River depending upon the time of year, spring thaw and summer thundershow- <br />ers. <br />4. Groundwater Hydrology <br />The Mancos Shale soils and overburden in the general area are poor for permeability of groundwa- <br />ter. The soiUoverburden thickness within the permit area is approximately 5 feet, below which exists <br />the 15-16 feet of gravel that will be mined. Underlying this gravel zone is the very thick and imper- <br />meable Mancos Shale. Alluvial groundwater levels are approximately 5-10 feet from the surface in <br />the permit area, depending upon the time of year, and more importantly, depending upon the river <br />19 Road Pit 10!02 5 <br />