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r Well 83-02. However, as no beneficial use is derived from this aquifer, the impact of the water level declines should be minimal. Twenty Mile Sandstone - Other than a slight increase in water levels, there is no apparent change in this aquifer. This observation is consistent with the PHC predictions.. Williams Fork Alluvium - The water level fluctuations observed in the Williams Fork Alluvium appear to be seasonal. This is consistent with the predictions of the PHC which stated that the discharge from the alluvium to the mines is roughly balanced by the discharge of mine water to the rivers. GrounBwater Quality Trout Creek Sandstone - I agree with the conclusion of the AHR that no adverse impacts from mining are evident in tlhe Trout Creek Sandstone. Middle Sandstone - I agree with the conclusion of the AHR that no adverse impacts from mining are evident in the Middle Sandstone. Twenty Mile Sandstone - The AHR states that no adverse impacts from mining are evident in the Twenty Mile Sandstone. However, the dissolve manganese concentration of 210 ug/L in W<ell 259 exceeds the Federal Secondary MCL of 50 ug/L by 320$. The elevated manganese concentration may be the continuance of a trend, as the 1990 mean concentration was also high (290 ug/L or 480 higher than the Secondary MCL). Although Secondary MCLs are primarily aesthetic guidelines, the Twenty Mile Sandstone is a drinking water aquifer, and this apparent trend should be watched. Williams Fork Alluvium - The AHR describes an upward trend of dissolved solids in Well AVF-3. However, Total Dissolved Solids (TDS) in both wells AVF-3 and AVF-6 have decreased since 1988 when the elevated TDS levels were first noted. In spite of the declining trend, TDS levels in the Williams Fork .Alluvium remain high and should be watched. MINE DISCNARGES Quantity Flow data for the No. 5 Mine discharge points have not been provided. The text summary of the AHR states tYiat the average discharge for the No. 5 Mine Sump and 7 Angle Nori;.h is less than that predicted by the PHC. Low discharge from 7 Angle North during the first quarter and end of 1991 were due to a pump malfunction. Quality Elevated levels of dissolved solids in mine discharge waters appear to be levelling off. Increased elevations of dissolved solids in 7 Angle North are reported to result from accumulation during the