2012-03-12_REPORT - C1982056 (2)

Home Browse Search

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 34). From 1994 through 1997, that trend has reversed and is generally decreasing from 1994 through 2000, and appears to have subsequently stabilized. 2011 was a record snow year, as exhibited by its spring melt elevated water level. 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. Several water years are presented to show relative seasonal fluctuations (Figure 36). POR conductivity data has exhibited a general increase since the late 1980's, but appears to have stabilized since 2007 (Figure 37). Downstream of 006 -AZ -3 are relatively new alluvial wells, AVF -13, AVF -14, and AVF -15. Data for sites AVF - 13, AVF -14, and AVF -15 are provided in Tables 29, 30, and 31, respectively. Figures 38 through 43 provide graphical representations of water levels and selected water quality parameters recorded at each new site. Note that localized mining subsidence along Fish Creek occurred in the area of well AVF -15 during the summer of 2004. The general location area of AVF -15 has subsequently been permanent ponded. Note that per our subsidence plan, alluvial 008 -AU3 replaced AVF -15 as the downstream monitoring well for subsidence evaluation in 2006. May of 2011 saw Fish Creek overflowing its banks in many areas. Significant flooding occurred in the area of these three wells, preventing access to the wells for water quality sampling and field measurements. It is anticipated that TC will request abandonment of these wells in a Revision in 2012 as they are no longer necessary for subsidence observations. Well 008 -AU -3 and surface water site 305 monitor water levels upstream from the Fish Creek Tipple area with data presented on Figure 44. The furthest downgradient Fish Creek alluvial monitoring well is 008 -AW -3 (Figure 46) located near the Fish Creek Tipple. No unusual water level fluctuations were noted at any of these sites during 2011. Similarly, conductivity values for these two sites were within historical ranges. Trout Creek Alluvial Groundwater: There are two Trout Creek alluvial monitoring wells, 008 -AT -1, and a privately owned well (Jones well). Figures 48 through 51 provide graphical representations of water level and field conductivity information to date. Tables 27 and 28 provide data for these wells. Well 008 -AT -1 is monitored in conjunction with surface water site 1005. Figure 48 depicts several water years for 008 -AT -1 for comparison. Monitoring was initiated on Trout Creek Alluvial wells back in 1994. Figure 49 shows TDS values for 008 -AT -1. Concentrations have been rising slowly since 2006. Note that the Jones well has historically been monitored to access potential mine impacts to the Jone's potable water well. In 2007, Mr. Jones constructed a weather /rodent cover and sealed off the well, restricting access for taking water level measurements. In the fall of 2008, TC provided the Jones family with underground water storage tanks, a new plumbing system, and imported water, so that they could discontinue use of the well. At that time, the old plumbing system to the Jones well was decommissioned eliminating alluvial water sampling access. It is TC's intend to submit a revision in 2012, to remove the Jones well from the permit. 9