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RAG, Empire Corporation ?000 AHR • continue to display increased stability and a slow recovery. Monitoring results through year ] 995 (Fig. ] 0) showed no apparent change in the water levels in the Twenit~mile Sandstone that could he attributable to mining activities. During 2000, 9 Mine well displayed some unusual fluctuations. while wells 259 and 84-01 remained stable. These responses are not believed to be mine-related as no unusual activities or additional mining occurred in the vicinity of these wells during 2000. RAGEC will continue to monitor these sites. The groundwater gradient in the Middle Sandstone in the vicinity of the mining operation generally decreases from the southeast to the northwest as reflected on Figure 11. The piezometric contour map of the Twentymile Sandstone is presented as Figure 12. This gradient remains generally consistent with previous years, according to 2000 measurements. WATER QUALITY The 2000 field parameter data forNo. 5 Mine well do not suggest any significant mining related water quality impacts to the Trout Creek Sandstone. The water quality data for this Trout Creek Sandstone well is summarized on Tables 5 and 6. A plot of field conductivity measurements is presented in Figure 13. The field parameter data for the three Middle Sandstone wells (TR-4, TR-7a, 81-01), again, • suggest no adverse impact or trend. Water quality data are sunmtarized in Tables 7 through 12. Plots of field conductivity for these Middle Sandstone Wells are presented in Figure 14. The conductivity measurements recorded at well 81-01 continue to stabilize at values near those typically observed for the other Middle Sandstone wells (TR-4 AND TR-7A). Wells TR-7A and TR-4 indicate slight reduction in concentrations of major ions over time. Historically, all three wells show reduction in concentrations of iron which shows considerable variation in concentrations. The general reduction in iron concentrations may be the result of better pwging of well bore volumes prior to sampling plus a switch to dissolved concentration analysis. The 2000 field parameter data for the two Twentymile Sandstone wells (No. 9 Mine Well and Well 259), do not suggest significant impact or trend. Water quality data for these Twentymile Sandstone wells are surtunazized in Tables 13 through 16. Plots of field conductivity over time are presented in Figure 15. Measurements during 2000 appeared normal. In summary, the water quality of all three sandstone aquifers does not indicate any significant trends or adverse impacts related to mining at Mines 5 and 6. COAL FLOWS • Plots of the measured discharges for the two #5 Mine discharge points aze presented in Figure I~\EnvironmenlallEMPIREWiR\2000\Text\Empire2000Ati R.doc Page 3