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• The potentiometric surface in the Twentymile Sandstone, as reflected by these six wells generally slopes from southwest to northeast. Water levels at wells 006-BRDH-7 (Figure 17), and 91M005 (Figure 19), remained consistent with that ofprevious years, with no mine impacts apparent. FBR-11-B (Figure 21) exhibited a decline in water level in 2002, although it should be noted that there had been a marked rise in water level beginning at the end of the 2001 water yeaz. Thus, despite a decline, water levels were generally higher than in previous yeazs. FBR-2 (Figure 23) has generally been declining since the late 1990s. It continues its declining trend in water level during 2002. 97013TH (Figure 27) exhibited a dse in water level as compared to previous years. The lower water levels typical in well 91M005 relative to historical values for well 006-82~8A continued (Figure 19). We1191M005 was established in 1993 to replace we11006-82118A, which was mined through during 1993. Field measurements are presented in Tables 8 and 9 for wells 006-BRDH-7 and 91M005. Field parameter measurements on these Twentymile Sandstone wells monitored during 2002 exhibited values within anticipated ranges, with no mine related impacts evident. Field measurements and water quality parameters for wells FBR- 11-B, FBR-2, 97012TH, and 97013TH aze provided on Tables 10 through 13. At well FBR-11-B (Table 10), new maximum values were recorded for £eld and lab conductivity, for bicarbonate and total dissolved solids, and for dissolved sodium, dissolved manganese, and sulfate during the second semiannual water quality analyses neaz the end of 2002. New minimum values for field and lab pH were also recorded during the second semiannual analyses. The TCC consultant, Miller Water Monitoring Service, indicated that he could "hear water rushing in" from the open casing after he had purged the well. These anomalous values may be associated with damage to the well casing, resulting in infiltration from another water zone. This well location will be evaluated further for • possible well damage and commingling of water from a source other than the Twentymile Sandstone, prior to the next episode of monitoring in 2003. A[ well FBR-2 (Table 11), a new minimum value was recorded for bicarbonate. Wells 97012TH (Table 12) and 97013TH (Table 13) established some new maximum and minimum values in 2002, but appeazed consistent with values observed in 2001. Note that these two wells were recently installed, and the existing data base is limited. None of these values fell outside the typical historical range of other wells in this aquifer. Trout Creek Sandstone: During 2002, six Trout Creek Sandstone wells, 001-83-106, 001-83-107, 95M001, FBR-2-E, 97012TC and 97013TC, required monitoring for water levels and field parameters on asemi-annual basis, and one well, 008-75-EFC, required an annual water level measurement. Wells 001-83-106, 95M001, FBR-2-E, 97012TC and 97013TC, also required water quality sampling on asemi-annual basis. All monitoring requirements were completed at these sites during 2002. Note that well FCM#2 was replaced in the fall of 1995 by monitoring we1195M001, with semi-annual monitoring during 2002 occurring at well 95M001 in lieu of FCM #2. Tables 14 through 20 provide summaries of the 2002 Water Yeaz data collected at each site. Table 14a provides the period of record statistical summary of collected data at well 001-83-106 with Tables 17a through 20a providing the period of record statistical summaries of collected data at wells 95M001, FBR-2-E, 97012TC and 97013TC. Figures 29 through 39 provide graphical representations of water levels and selected water quality parameters recorded at each site. • The pumping of well 001-83-106 (Figure 29) complicates the potentiometric surface in the Trout Creek Sandstone. The poten[iometric surface trends prevalent in the Twentymile Sandstone and Wadge Overburden aquifers are not evident in the monitored Trout Creek wells. The previously monitored well 006-83-48C 5