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(USGS). Prior to the 1989 Water Year, the USGS also collected and analyzed water quality samples from <br />• the site. Since the 1989 Water Year, Cyprus collects water quality samples for subsequent analysis by ACZ <br />laboratories. Unless otherwise indicated, all references to "1994" in this report to refer to the 1994 Water <br />Year. <br />BEDROCK GROUNDWATER MONTfORING <br />The Wadge Overburden formation (including the Wadge coal seam) overlies the Trout Creek Sandstone and <br />underlies the Twentymile Sandstone. All three geologic units are monitored within the Foidel Creek Mine <br />permit area. <br />Wadge Overburden: During 1994, four Wadge Overburden wells (009-79-4, FBR-11-A, 006-82-74C, and <br />( \"~ 91M006) required monitoring for water levels, field parameters, and water quality parameters on a semi- <br />~n~ annual basis. Monitoring requirements were completed with the exception of a water level measurement <br />,MCJ, omission occurring in-May 1994 at well 006-82-74C. Field parameters and a water quality sample were <br />~~` obtained from the site but the water level was inadvertently not recorded. Tables 1 through 4 provide <br />summaries of the 1994 Water Year data collected at each site. Tables la through 4a provide period of <br />• record statistical summaries of collected data at each site. Figures 3 through 10 provide graphical <br />representations of water levels and selected water quality parameters recorded at each site. <br />The potentiometric surface in the Wadge Overburden is generally observed to slope from south to north in <br />monitored wells. During 1994, water levels were observed to remain fairly static with a slight declining <br />trend evident in well 91M006. This well was established in the fall of 1991 as a replacement for well 006- <br />87-1 which was destroyed by mining. The apparent continuing declining trend in well 91M006 may be <br />related to localized dewatering of the formation as a result of mining activities in the vicinity. Water levels <br />at wells 00'9-79-4, FBR-11-A, and 006-74-C remained essentially stable during 1994 with no mining impacts <br />apparent. <br />No anomalous water quality impacts attributable to mitring were evident in data collected from Wadge <br />Overburden wells during 1994. Water quality parameters were observed to remain within established ranges <br />at well 009-79~ with the exception of a slightly elevated selenium value returned from the October <br />sampling. Five measured parameters at well FBR-11-A returned values outside of previously established <br />ranges during 1994, however, none are believed to evidence mine related impacts. The relatively short <br />period of record available for this site contributes to this result as normal ranges are still being established. <br />Specifically at well FBR-11-A, new minimum field pH, alkalinity, bicarbonate, and carbonate values were <br />recorded in October along with a new maximum dissolved lead value. In May, a slightly increased new <br />• maximum bicarbonate value was recorded. At well 006-82-74C, water quality parameters were observed <br />to remain within established ranges with the exception of slightly elevated new maximttm field and lab <br />-2- <br />