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• Outfall 003, a.k.a. site SD. Under TC, monitoring of these sites remains the same as in the active mining monitoring plan. Summaries of the available water quality data for the mine discharge sites are presented in Tables 7 through 10. The plot of dissolved solids presented in Figure 5 shows that [he average dissolved solids in the Eagle No. 5 Mine discharge water have increased slightly from about 800 mg/1 in 1982 and 1983 to between 1022 mg/1 and 2600 mg/1 (a new maximum) in December 2005. The new maximum may be the result of chopping ice for sample collection with may have disturbed sediment. A subsequent water quality analysis in January 2006 indicated a much lower TDS concentration of 910 mg/1. The average dissolved solids concentration for the 9P3 was 1100 mg/1 in 2003 (Note: 9P3 did not flow in 2004 or 2005), which is a return to values common in 1994 and 1995. Water levels for the 7 North Angle well are monitored on a quarterly basis. This data is presented in Table 9A. 3.1.3 ALLUVIAL WELLS Water quality in the Williams Fork River Alluvium is monitored via alluvia] well AVF-5, which is located adjacent to the underground discharge sediment ponds area (See Figure 2). Under TC, AVF-5 is measured for water level and field parameters on an annual basis (between July 20th and August 30th) concurrent with the Williams Fork surface water sampling (site WF-1). No water quality analyses are required for AVF-5 under TC. Historically, groundwater levels in the alluvium have remained fairly regular, with normal seasonal fluctuations, apparently related to changes in river levels. POR groundwater levels in AVF-5 are plotted in Figure 6. The data indicates no impact on alluvial water levels related to mining. Field parameter data for AVF-5 for 2005 is presented in Table 11. POR water quality data is provided in Table 12. A plot of field electric conductivity versus time is presented in Figure 7. There has been no conclusive evidence of seasonal variation of water quality in the alluvium. AVF-5 was within historic levels in 2005. 3.2 Surface Water Monitoring 3.2.1 Rivers There are two rivers in the vicinity of the mine site. The Yampa River, flows in a southeasterly direction across the mine site. The Yampa River drains most of the northeast corner of Colorado and part of south- central Wyoming. The second river is the Williams Fork, which is a major tributary of the Yampa River. The Williams Fork River joins the Yampa River on the mine property. Monitoring data is collected for the Williams Fork River. The United States Geologic Survey (USGS) had one gaging station and one staff gage for collection of 4 I:\Env\EmpireW HR\2005\TeM\Empire2005AHR.doc