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than the downgradient wells. Upgradient water levels near the east side of the permit boundary appear to be related to the fluctuations observed in all three of the downgradient Middle Sandstone wells. The water level decline in this upgradient area prior to 1984 and the subsequent recovery up to 1988 closely parallels the trends observed in two of the downgradient wells. The decline during the first part of 1991 also parallels the trend in these two wells. However, the rapid decline during the last part of 1989 and the first part of 1990 appears to follow the trend observed on the southeast end of the permit area, although the magnitude of decline is considerably less. Water levels in the upgradient Middle Sandstone monitoring well, 83-03, located furthest (more than 1.5 miles north) from active underground operations for Mines 5 and 6 show a pattern that requix-es further excplanation,~given that ground water in that area is under flowing artesian conditions. The overall trend in this area from 1984 through 1992 suggests a decline in potentiometric levels of about 25 feet, based on the linear regression line included on Figure 17 in Section 2.04.7 of the permit application package. However, the occasional sharp decline in Well 83-03 followed by rapid recovery which appear in the time plc•t are likely the result of errors in obtaining an accurate measurement of equilibrium artesian pressures within the well. The long-term decline could be a pressure response due to the overall drop in piezometric levels in the Middle Sandstone in the vicinity of Mines 5 and 6. On the other hand, there was no apparent relationship between the fluctuations observed in Well 83-03 with the fluctuations observed in other Middle Sandstone wells due perhaps to possible pressure measurement fluctuations and the further distance to the well. The ground water gradient in the Middle Sandstone rangers from 60 to 120 feet per mile to the southwest. The drop in piezometric levels in the Middle Sandstone unit above the subsided longwall mine panels in the F and S coal seams has creaCed a potentiometric gradient to the south in the vicinity of the longwall panels. The data for the three Middle Sandstone wells which are monitored for water quality show no adverse impact or trend. Plots of field conductivity for these Middle Sandstone wells are presented in Figure 5811. Wells TR-7A and TR-4 indicate slight reduction in concentrations of major ions over time. All three wells show reduction in concentrations of iron, which shows considerable variation in concentrations. The general x•eduction.in.iron concentrations may be the result of better purging of well bore volumes prior to sampling, plus a switch to dissolved concentration analysis. In summary, the areas of the Middle Sandstone which are located closest to the mine workings have experienced the greatest impact with regard to water levels. Much of the impact is presumed to be due to mine dewatering, although some water level declines appear to be related to subsidence. The direction of the ground water gradient also appears to have been affected by subsidence. Ground water quality in the Middle Sandstone does not appear to have been adversely affected by mining. Twentymile Sandstone Water level monitoring results through year 1992, provide=_d in Figures 18 through 20 in Section 2.04.7 of the permit application package, show no change in the piezometric levels in the Twentymile Sande':one that could be attributable to mining activities. The only trend indicated in these plots is, perhaps, a slight increase in the levels in Well 84-01. The water quality data for the two Twentymile Sandstone wells, No. 9 Mine Well and Well 259 show no adverse impact or trend. Plots of field 23