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• be found in previous AHRs. Tables l0a through 14a provide the historical statistical summaries of collected data <br />at wells 001-83-106, 001-83-107, 95M001, FBR-2-E, and 97013TC, respectively. Figures 18 through 25 provide <br />graphical representations of water levels and selected water quality parameters recorded at active sites. <br />The pumping of TCC domestic water we11001-83-106 (Figure 18) complicates the potentiometric surface in the <br />Trout Creek Sandstone. Water levels in well 001-83-106 were showing a slight increase since 1998, which <br />appears to have stabilized back in 2003. The potentiometric surface trends prevalent in the Twentymile Sandstone <br />and Wadge Overburden aquifers are not evident in the monitored Trout Creek wells. The previously monitored <br />we11006-83-48C routinely exhibited water levels in the 7100 ft elevation range while replacement well FCM#2 <br />exhibited levels around the 6520 ft elevation during 1995. In the fall of 1995, well 95M001 was established in <br />part to address the apparent discrepancy in water levels between wells 006-83-48C and FCM#2. Water levels <br />from well 95M001 confirm that levels recorded from well FCM #2 were accurate (Figure 20). Mining in the <br />northern mining district began in 1995, which is down dip of this well. Water levels in we1195M001 declined <br />since 1994, but appear to have stabilized since 2002 (Figure 20). The original decline may have been influenced <br />by the mining operation. <br />Significant inflows from the Trout Creek Sandstone into the mine workings have not been encountered to date to <br />account for the apparent lowering of the potentiometric surface in the Trout Creek formation, as indicated by the <br />water level data previously recorded for well 006-83-48C. Some dewatering of the aquifer does occur from the <br />pumping of we11001-83-106 to supply the mine with domestic water. <br />• <br />The southernmost Trout Creek well, 001-83-107 (Figure 19), water levels continue to decline. Located down dip <br />of the TCC facility water well (001-83-106), steady declines in water level since the early 1990 may reflect <br />effects from longwall mining that began in the western mining district in 1990, in addition to water well use <br />(Figure 21). <br />Well FBR-2-E (Figure 22), located along the eastern permit boundary exhibited consistent water levels until early <br />1999, then dropped about 50 feet and immediately stabilized with consistent water levels at the lower depth to <br />date. The specific reason for this drop is not apparent, although many historical boreholes and some faulting <br />exists in this general vicinity. Water levels were at the 6667 ft elevation during 2007, which is similar to the <br />previous four water years. TDS values for FBR-2-E (Figure 23) dropped in 2001, rebounded back to historical <br />values, and began dropping again in 2005 through 2007. Although close to historic values, 2007 exhibited an <br />historic low TDS of 730 mg/1. The exact reason for this decline is unknown, and does not appear to correspond <br />with stable water levels. <br />We1197013TC (Figure 24) water levels remain consistent with that of the last two years. Water quality values for <br />we1197013TC (Figure 25) appear consistent with historical values. <br />Fish Creek Sandstone: Two Fish Creek Sandstone wells (91M001 and 91M004) require monitoring on a <br />semiannual basis for water level only. An additional well (Ashley) requires semi-annual monitoring for water <br />levels and field parameters, and annual water quality sampling. Tables 15 through 17 provide summaries of the <br />2006 Water Year data collected at each site. Tables 15a through 17a provide historical statistical summaries of <br />6 <br />