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1 <br />' GROUND WATER MONITORING <br />' Bedrock <br />Two wells in the Wadge Overburden (which includes the Wadge Coal) <br />' are monitored. Water Levels - Levels in the wells have been <br />measured since 1979 (Figures 4 and 5). Water levels in Well <br />008-79-6 rise abruptly in 1980 with a slight increase during the <br />' period 1983 through 1986, followed by a slight decrease during the <br />period 1987 through 1991. The abrupt rise in 1980 is probably due <br />to water level recovery in the Wadge Coal and overburden following <br />cessation of mining in the vicinity of this well in 1979 or 1980. <br />The trends from 1983 on appear to follow the overall climatic trend <br />as illustrated in the flow data in Figures 12 and 14. <br />The data reported in Figures 4 and 5 indicate that the water levels <br />in the Wadge overburden varies seasonally: The water levels in the <br />spring are usually higher than in the fall. Seasonal fluctuations <br />in both overburden wells varies as much as l0 feet although the <br />' seasonal fluctuation in Well 008-79-6 appears to have diminished in <br />the time period following 1986.. Water level fluctuations in the <br />nearby alluvial well 008-AV-2 show a similar pattern suggesting <br />that the seasonal fluctuation and general trend since 1986 are the <br />result of related to trends and fluctuations in Foidel Creek and <br />its alluvium. <br />' The water level fluctuations and trends in Well 008-77-58 are more <br />difficult to explain. The water levels have dropped abruptly <br />between 1979 and 1980. The reason for the decline is not apparent <br />' but may have been related to dewatering during the aborted <br />underground mining at Mine No. 3 during May 79 to June 1980. Water <br />level recoveries, however, are not abrupt and seem to following the <br />longer term climatic trend with slight increases for the wetter <br />period 1982 through 1986 followed by a slight decrease for the <br />dryer period 1987 through 1991 as reflected in the flow data in <br />Figures 12 and 14. The seasonal fluctuation in Well 008-77-58 do <br />not appear to have diminished in the time period following 1986 <br />like Well 008-77-06, perhaps because it location is more isolated <br />from the streams and associate alluvium. <br />Water Quality - The water quality data for the Wadge Overburden <br />' wells are summarized on Tables 4 through 7. Plots of dissolved <br />solids for both wells are presented in Figure 6. There is too much <br />fluctuation in the concentration data prior to 1986 in Well <br />008-77-58 to determine a background concentration or a trend in <br />' concentrations. Ion composition data indicates a decline in sodium <br />concentrations since 1983. TDS concentrations in both wells appear <br />to have stabilized at around 1000 mg/1 in 1991. TDS concentrations <br />' in Well 008-79-6 appear to have increased slightly over the period <br />1986 through 1989 perhaps reflecting the increase in specific <br />conductance in Foidel Creek over the same time period (see Figure <br />' - 2 - <br /> <br />