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Figure 17 is a monthly tabulation of meter readings far 2001. While mining is in temporary cessation, the <br />• mine is being flooded and pumps were mn only periodically to maintain appropriate mine water levels. <br />Following approval of the June 2001 Temporary Cessation Monitoring Plan, meter readings were no longer <br />recorded for the No. 5 Mine and 7 North Angle sites. <br />Summaries of the available water quality data for [he mine dischazge sites are presented in Tables 17 through <br />20. The Eagle No. 5 Mine sump dischazge is CDPS dischazge point, 003. The 7 North Angle Dischazge is <br />CDPS discharge point 024. The plot of dissolved solids presented in Figure 18 shows that the average <br />dissolved solids in the Eagle No. 5 Mine discharge water have increased slightly from about 800 mg/1 in 1982 <br />and 1983 to 925 mg/1 in 2001. Similazly, the average dissolved solids concentration for the 7 North Angle <br />were 970 mg/1 in 2001, which is a return to values common in 1994 and 1995. <br />3.1.3 ALLUVIAL WELLS <br />Water quality in the Williams Fork River Alluvium is monitored. Three alluvial wells (AVF-3, AVF-5, and <br />AVF-6) aze located in the loadout facility and underground discharge sediment ponds areas (See Figure 2). <br />Groundwater levels in the alluvium have remained fairly regular, with normal seasonal fluctuations, <br />apparently related to changes in river levels. Groundwater levels in the alluvium are plotted in Figure 19. A <br />piezometric map for the Williams Fork Alluvium is presented as Figure 20. The data indicates no impact on <br />alluvial water levels related to mining. <br />Summaries of the water quality data for the alluvial wells aze presented in Tables 21 through 26. A plot of <br />field electric conductivity versus time is presented in Figure 21. There is no conclusive evidence of seasonal <br />variation of water quality in the alluvium. The field conductivity measurements of Well AVF-5 were above <br />normal in late 1983 and early 1984, however, laboratory measurements did not show the same high levels <br />during that period. AVF-5 was within historic levels in 2001. <br />Well AVF-3 has shown a long term variability in field conductivity, from below 2000 umhos/cm in 1993 and <br />1994, increasing above 2000 umhos/cm in 1996 and 1997, and maintaining below 2000 umhos/cm since the <br />beginning of 1998. There is also a correlative increase in calcium, magnesium, sulfate and chlorides. The <br />source of this change is not known. However, it is unlikely to be the result of mine dischazge, because of the <br />dischazge's down gradient location and the dissimilaz chemical composition of mine dischazge water. The <br />mine dischazge water is strongly sodium-bicarbonate water with a conductivity of approximately 1500 <br />umhos/cm, while AVF-3 water is typically a mixed sodium-magnesium-calcium-bicarbonate-sulfate-chloride <br />water with conductivity averaging approximately 1700 umhos/cm in recent years. <br />AVF-6, which exhibited relatively higher conductivity values in 2000 appeazs to have returned to more <br />historic values in 2001. Higher values in 2000 did not appear to be related to commingling with the <br />wastewater lagoon, as the conductivities in the well water have historically exceeded [he levels measured in <br />• the wastewater (approximately 1500 umhos/cm), and water discharged to the lagoon is primarily Trout Creek <br />5 <br />I:\Env\Empire\AHR\2001 \Text\Empire2001 AHR.doc <br />