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conductivity values. This well has historically exhibited relatively higher conductivities and TD5 • concentrations than other Wadge wells: This may be attributable to the influence of spoil water at this site as the well is located downgradient of reclaimed surface mined areas. Seven measured parameters at well 91M006 returned values outside of previously established ranges during 1994, again however, none are believed to evidence mine impacts as the relatively short period of record available for this site contributes to this result. Specifically at well 91M006, new minimum field wnductivity, alkalinity, and TDS values along with new maximum field temperature and dissolved iron values were recorded in May. New minimum pH, alkalinity, TDS, and sulfate values with new maximum dissolved lead and iron values were recorded in October. -~ Twentymile Sandstone: During 1994, two Twentymile Sandstone wells (006-BRDH-7 and 91M005) required ~` 1 monitoring for water levels and field parameters on asemi-annual basis. Monitoring requirements were r''~yS completed with the exception of a water level measurement omission occurring in May 1994 at well 006- BRDH-7. Field parameters obtained from the site but the water level was inadvertently not recorded. Well 006-BRDH-7 has historically exhibited extremely low pressure heads and it is unlikely significant variation from the norm occurred in May. Tables 5 and 6 provide summaries of the 1994 Water Year data collected at each site. Figures 11 through 14 provide graphical representations of water levels and selected water quality parameters recorded at each site. • The potentiomettic surface in the Twentymile Sandstone is also generally observed to slope from south to north in monitored wells. During 1994, water levels were observed to remain stable with no mine impacts apparent. However, a markedly lower water level is noted in well 91M005 relative to well 006-82-48A. Well 91M005 was established in 1993 to replace well 006-82-48A which was mined through during 1993. Although not required, full suite analyses on water quality samples drawn from we1191M005 were conducted during 1994. Results are presented in Table 6. Field parameter measurements on both Twentymile Sandstone wells monitored during 1994 returned values within anticipated ranges with no mine related impacts evident. Trout Creek Sandstone: During 1994, three Trout Creek Sandstone wells (001-83-106, 001-83-107, and / ~ FCM A'2) required monitoring for water levels and field parameters on asemi-annual basis. An additional `\.t~ l well (008-75-EFC) required an annual water level measurement. Wells 001-83-106 and FCM N2 also ~~h required water quality sampling on a semi-annual basis. Three water level monitoring omissions occurred during 1994. Field parameters were obtained in May from wells 001-83-106 and 001-83-107, however, water levels were inadvertently not recorded. In addition, the required annual water level measurement at well 008-75-EFC was not obtained. Changes in personnel during the latter part of 1993 and early 1994 contributed to the inadvertent failure to monitor this location. TCC has identified this omission and taken steps to ensure that required data will be obtained from this site in the future. Completion work on well FCM Jl2 occurred during the summer of 1994. A subsequent water level measurement was obtained September. Tables 7 through 10 provide summaries of the 1994 Water Year data collected at each site. -3-