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• Summaries of the available water quality data for the mine discharge sites are presented in Tables 7 through <br />10. The plot of dissolved solids presented in Figure 5 shows that the average dissolved solids in the Eagle <br />No. 5 Mine dischazge water have increased slightly from about 800 mgA in 1982 and 1983 to 940 mg/l in <br />2002. Similarly, the average dissolved solids concentration far the 7 North Angle was .910 mgA in 2002, <br />which is a return to values common in 1994 and 1995. Water levels for the 7 North Angle well are monitored <br />on a quarterly basis. This data is presented in Table 9A. <br />3.1.3 ALLiIVIAL WELLS <br />Water quality in the Williams Fork River Alluvium is monitored via alluvial well AVF-5, which is located <br />adjacent to the underground dischazge sediment ponds azea (See Figure 2). Under TC, AVF-5 is measured for <br />water level and field parameters on an annual basis (between July 20th and August 30th) concurrent with the <br />Williams Fork surface water sampling (site WF-1). No water quality analyses are required under TC. Note <br />that monitoring was conducted eazly for site AVF-5 on July 17, 2002. This was brought to the attention of <br />Mc Tom Kaldenbach (DMG) during a telephone conversation with Mr. Brian Watterson (TCC) on July 31, <br />2002, during which time Mr. ICaldenbach agreed that the eazly monitoring still fulfilled the intent of the <br />monitoring/sampling plan after peak flow for the 2002 season, and that no further monitoring was required. <br />This is also outlined in a follow-up letter from TCC to DMG dated August 1, 2002. <br />Historically, groundwater levels in the alluvium have remained fairly regulaz, with noanal seasonal <br />. fluctuations, apparently related to changes in river levels. POR groundwater levels in AVF-5 are plotted in <br />Figure 6. The data indicates no impact on alluvial water levels related to mining. <br />Water quality data for AVF-5 for 2002 is presented in Table 11. POR water quality data is provided in Table <br />12. A plot of field electric conductivity versus time is presented in Figure 7. There has been no conclusive <br />evidence of seasonal variation of water quality in the alluvium. The field conductivity measurements of AVF- <br />5 were above normal in late 1983 and eazly 1984, however, laboratory measurements did not show the same <br />high levels during that period. AVF-5 was within historic levels in 2002. <br />3.2 Surface Water Monitoring <br />3.2.1 Rivers <br />There are two rivers in the vicinity of the mine site. The Yampa River, flows in a southeasterly direction <br />across the mine site. The Yampa River drains most of the northeast comer of Colorado and part of south- <br />central Wyoming. The second river is the Williams Fork, which is a major tributary of the Yampa River. The <br />Williams Fork River joins the Yampa River on the mine property. Monitoring data is collected for the <br />Williams Fork River. Monitoring data is also collected from one spring, the No. 1 Ship Pit (CDPS Outfall <br />022 or 1SP). <br />The United States Geologic Survey (USGS) had one gaging station and one staff gage for collection of <br />4 <br />I:\Env\E mpire\AH R\2002\TextlEmpire2002AHR.doc <br />