Laserfiche WebLink
Foidel Creek Alluvial Groundwater: During 1995, three Foidel Creek alluvial wells (009-S-10, 001-5-5, <br />and 008-AV-2) required monitoring for water levels and field parameters on a monthly basis, and water <br />quality sampling on a quarterly basis. An additional well (008-AV-1) required only montlily monitoring for <br />water levels and field parameters. All monitoring requirements were met at these sites. Tables 11 through <br />14 provide summaries of the 1995 Water Year data collected at each site. Tables l la through 13a provide <br />period of record statistical summaries of collected data at each site. Figures 20 through 28 provide graphical <br />representations of water levels and selected water quality parameters recorded at each site. <br />Water levels during 1995 remained consistent with established ranges and patterns and showed the typical <br />seasonal variability of elevated water levels in the spring. Well 009-S-10 provides data for the alluvial <br />aquifer upgradient from the mine portals. Well 001-S-5 is located just downgradient form the mine portals <br />and surface facilities location and is monitored in conjunction with surface water monitoring site 8. Figure <br />24 is indicative of the general relationship between the alluvial groundwater elevations and surface water <br />elevations at these two sites. Wells 008-AV-1 and 008-AV-2 are monitored in conjunction with surface <br />water site 304 at a point on Foidel Creek approximately 1000 feet upstream of the confluence of Foidel and <br />Middle Creeks. Water levels in these wells and the stream show the typical seasonal interrelationship of <br />relatively rapid increases and declines associated with spring runoff (Figure 25). The longer term trends <br />in water levels at these sites generally parallel the fluctuations observed in annual streamflows. <br />• Field conductivity measurements in general at well 001-5-5 are higher than the upgradient site 009- <br />5-10. Conductivity values at well 009-S-10 fluctuated within previously established ranges during 1995 with <br />the exception of an unusually hieh value recorded in March. The increasing field conducfivity trend noted <br />in 1994 for well 001-5-5 appears evident again in the 1995 data although overall increases are small. Field <br />conductivity measurements at wells 008-AV-1 and 008-AV-2 are comparable to measurements at well 001-5- <br />5 and occurred within previously established ranges for these sites. As indicated on Figure 28, TDS <br />concentrations at well 008-AV-2 continue to appear to be increasing although measured levels returned in <br />1995 were much less consistent than in previous years. TCC will continue to monitor the direction of this <br />trend. <br />At well 009-5-10, the January field conductivity was unusually high. The SAR value returned in May was <br />somewhat elevated as well, however, both measured parameters subsequently returned to normal ranges. <br />All other measured parameters at well 009-5-10 returned values within the previously established ranges <br />throughout the monitoring year. At well 001-5-5, an elevated conductivity measurement was noted in <br />January as well. The previously established maximum total alkalinity value at well 001-S-5 was exceeded <br />in December, March, and August with a new maximum bicarbonate value detected in August; elevated TDS <br />values were returned in December and March. We11008-AV-2 exhibited new maximum total alkalinity and <br />ammonia levels in December. Elevated dissolved solids and nutrient values were detected in March (see <br />Table 13). Values returned to their normal ranges in August except for a slightly elevated TDS <br />• concentration. Elevated dissolved manganese concentrations noted during the 1994 Water Year were <br />observed to return to typically lower levels in 1995. Field parameter measurements at well 008-AV-1 <br />-5- <br />