2009-03-03_REPORT - C1982056 (2)

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alluvial aquifer upgradient from the mine portals. Water levels in 009-5-10 for 2006 (Figure 29) are consistent . with observed historical seasonal fluctuations. Conductivity values at well 009-S-10 (Figure 30) remain consistent with historical values. Well 001-5-5 is located just downgradient from the mine portals and surface facilities location, and is monitored in conjunction with surface water monitoring site 8. Water levels and conductivity values in 001-S-5 for 2008 (Figure 31 and 32) are consistent with observed historical seasonal fluctuations. Figure 33 is indicative of the general relationship between the alluvial groundwater elevations and surface water elevations at these two sites. Data for wells 008-AV-1 and 008-AV-2 are provided in Tables 21 and 22, respectively. 2008 data was consistent with historical values. Water levels in these wells and the stream show the typical seasonal interrelationship of relatively rapid increases and declines associated with spring runoff . The longer-term trends in water levels at these sites generally parallel the fluctuations observed in annual stream flows. Field conductivity measurements in general at well 001-5-5 were noted to be slightly lower the upgradient site 009-5-10. Downgradient, field conductivities at well 008-AV-2 ranged between 1420 and 1840 for 2008. Conductivity values at well 009-S-10 fluctuated within previously established ranges during 2006. There appears to be a general increasing field conductivity trend for well 001-5-5. Field conductivity measurements at wells 008-AV-1 and 008-AV-2 are comparable and occurred within previously established ranges for these sites. Fish Creek Alluvial Groundwater: Monitored water quality parameters exhibited values at the Fish Creek alluvial wells which were typically within previously established ranges. There are four older Fish Creek alluvial wells (006-AY-1, 006-AZ-3, 008-AU-3 and 008-AW-3). Tables 23 through 26 provide summaries of the.: 2008 Water Year data collected at each site. Tables 23a through 26a provide POR statistical summaries of collected data at each site. Figures 34 through 37 provide graphical representations of water levels and selected water quality parameters recorded at each site. In addition to the four wells discussed above, three additional alluvial wells, AVF-13 and AVF-14 (installed in August 2001), and AVF-15 (installed June 2002) were added per PR99-05, 4e-7. Monitoring frequencies for these wells are different than that for the four older wells above (see Table 18). Water levels at well 006-AY-1, located on Fish Creek upstream of the Southwest Mining District and Mine 2, had exhibited a relatively steady increase in water level from approximately 1990 through 1994 (see Figure 38). From 1994 through 1997, that trend has reversed and is generally decreasing from 1994 through 2008 The maximum fluctuation in water level at this site over the period of record is 8.5' to date. POR conductivity data has been relatively consistent the last several years (Figure 35). Well 006-AZ-3 is situated downstream of 006- AY-1 and below the Fish Creek Borehole. Well 006-AZ-3 is monitored in conjunction with surface water site 307 and the water level relationship is presented as Figure 36. Again in 2008, the interrelationship between alluvial groundwater and surface water is evident on this plot. POR conductivity data has exhibited a general increase since the late 1980's (Figure 37). 8