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• Groundwater discharge on the property is by small seeps and springs from sandstones that <br />overlie the impermeable shales. During the initial exploration phase and subsequent <br />hydrologic investigations, such as the 1979 LRCWE study, no significant quantities of <br />groundwater were observed to be flowing from the sandstones. Seeps and small springs that <br />were observed were consumed entirely. As stated earlier, there is no significant groundwater <br />discharge from the sandstones to the mine pit. Recharge to the spoils is minimal as evidenced <br />by the lack of water encountered while reinstating the 6900 level water monitoring well. A <br />discussion of this well is included in the 1986 Annual Report. <br />Some groundwater discharge from the Trout Creek Sandstone and sandstones beneath the <br />Trout Creek may occur to Goodspring and Taylor Creeks. Discharge from these sandstones <br />to the creeks is a result of recharge to these sandstones near the headwaters of both creeks. <br />Beneath Goodspring Creek, the sandstones are under artesian pressure which probably allows <br />for minimal groundwater discharge by vertical percolation. <br />Groundwater Quality <br />General Area <br />Water samples collected in the vicinity of the Colowyo Mine permit area by federal agencies <br />and consultants for the Colowyo Coal Company indicate that the water quality is generally <br />poor and variable. Data collected by the USGS are presented in open-file Report 78-23, <br />"Selected Hydrologic Data, Yampa River Basin and Parts of the White River Basin, <br />• Northwestern Colorado and South Central Wyoming", Giles and Brogden (1978). <br />Examination of the data presented in this report indicates that concentrations of trace metals <br />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 <br />pattern or conclusions describing their occurrence could be determined. Table 1 is a summary <br />of water quality data collected from USGS observation wells completed in the vicinity of the <br />Colowyo Mine permit area. This data is presented in the USGS Open-file Report 78-23; Giles <br />and Brogden (1978), and have been extracted from that report. <br />2.04.7-12 Revision Date: 6/28/05 <br />Revision No.: MR-73 <br />