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mg/I since 1987. <br /> <br />PONDS <br />There was only one discharge from the sediment ponds in 1995. The date for <br />discharge point 004 is presented on Table 33. <br />HYDROLOGIC IMPACTS <br />No significant unpredicted adverse impacts were detected during 1995. The continued <br />drawdown in the Middle Sandstone unit is determined to be the most significant <br />impact related to mining operations associated with Mines 5 and 6. The Probable <br />Hydrologic Consequences section of the Permit predicted drawdown in the Middle <br />U Sandstone unit associated with mining the F and E coal seams at Mines 5 and 6, <br />although the extent and magnitude of the drawdown were not quantified. A worst case <br />evaluation was, however, prepared for the overlying Twentymile Sandstone. The <br />drawdown in Middle Sandstone Well TR-4 attributable to the longwall mining in the E <br />and F seams at a distance of approximately one mile is determined to be between 50 <br />and 60 feet. This is comparable to the 60 foot drawdowns projected in the PHC for <br />the overlying Twentymile Sandstone at a distance of one mile from the location of <br />mine subsidence. No measurable drawdown has been observed in the Twentymile <br />Sandstone. The impacts observed in the Middle Sandstone are comparable to the <br />worst case projections developed for the Twentymile Sandstone. A small increase in <br />the dissolved solids in Williams Fork Alluvium Well AVF-3 to above 2000 mg/L has <br />C-81-044 1995 AHR (Revised 1/97) Page 12 <br />