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RULE 2 PERMITS <br />This recharge rate includes groundwater recharged to the alluvial aquifer of Goodspring Creek and <br />groundwater recharged to deeper sandstones below the elevations of Goodspring Creek. Because no <br />appreciable quantities of water were observed to be discharging from the upper sandstones on the mine <br />property and because no appreciable quantities of groundwater were observed during the drilling <br />operations, the calculated recharge rate for the Goodspring Basin is probably closer to an estimate of <br />recharge to the alluvium materials in the valley of Goodspring Creek. Recharge rates of the sandstones <br />that contribute to Goodspring Creek are probably considerably less. <br />Groundwater discharge on the property is by small seeps and springs from sandstones that overlie the <br />impermeable shales. During the initial exploration phase and subsequent hydrologic investigations, such <br />as the 1979 LRCWE study, no significant quantities of groundwater were observed to be flowing from the <br />sandstones. Seeps and small springs that were observed were consumed entirely. As stated earlier, there is <br />no significant groundwater discharge from the sandstones to the mine pit. Recharge to the spoils is <br />minimal as evidenced by the lack of water encountered while reinstating the 6900 level water monitoring <br />well. A discussion of this well is included in the 1986 Annual Report. <br />Some groundwater discharge from the Trout Creek Sandstone and sandstones beneath the Trout Creek <br />may occur to Goodspring and Taylor Creeks. Discharge from these sandstones to the creeks is a result of <br />recharge to these sandstones near the headwaters of both creeks. Beneath Goodspring Creek, the <br />sandstones are under artesian pressure which probably allows for minimal groundwater discharge by <br />vertical percolation. <br />Groundwater Ouali <br />General Area <br />Water samples collected in the vicinity of the Colowyo Mine permit area by federal agencies and <br />consultants for the Colowyo Coal Company indicate that the water quality is generally poor and variable. <br />Data collected by the USES are presented in open-file Report 78-23, "Selected Hydrologic Data, Yampa <br />River Basin and Parts of the White River Basin, Northwestern Colorado and South Central Wyoming", <br />Giles and Brogden (1978). Examination of the data presented in this report indicates that concentrations <br />of trace metals rarely exceed the health limits. Intermittently throughout the Yampa River Basin, <br />concentrations of trace metals were observed to exceed the limits. However, no apparent pattern or <br />conclusions describing their occurrence could be determined. Table 2.04.7-2 is a summary of water <br />quality data collected from USGS observation wells completed in the vicinity of the Colowyo Mine <br />permit area. These data are presented in the USGS Open-file Report 78-23, Giles and Brogden (1978), <br />and have been extracted from that report. <br />Giles and Brogden (1978) reported the results of water quality analyses of samples collected in streams, <br />springs, and wells of the Yampa River Basin in 1974 and 1975. Approximately 27 samples were collected <br />and analyzed for bacteria, trace elements, common ions, temperature and pH. Temperature and specific <br />conductivity results in the vicinity of Taylor Creek are listed in Table 2.04.7-3. Fifteen wells were <br />sampled in the vicinity of the Colowyo Mine. The average specific conductivity measured in the wells <br />was 1390 mmhos and the range was almost as large as that for the surface water samples, 720 to 2700 <br />mmhos. <br />After three years of data collection, the main conclusion reached by Giles and Brogden was a <br />confirmation of the general alkalinity of the water and the recognition of the variability of quality in both <br />surface and groundwater. <br />Rule 2 Permits 2.04.7-5 Revision Date: 6/23/08 <br />Revision No.: MR-91