Laserfiche WebLink
includes those values during the period from 1981-1991. It is uncleaz how those <br />terms differentiate short and long term for the same time period. Please update <br />and clarify the prediction for TDS levels in Trout Creek for both the short term <br />(current five year permit term) and the long term (ten to twenty years beyond <br />mining, as was previously stated in the PHC). <br />d. Section I.B.l.a, long term average, provides annual averages and standazd <br />deviations from those averages for TDS levels at TR-B, TR-C, and TR-D. It is <br />uncleaz how these averages and deviations were derived from the data. When <br />the data from the tables is averaged monthly and annually, exclusive of 1992 <br />data, the outcome is not equal to that listed in Section 1.B.l.a. Averaging with <br />the omission of data from 1990 and 1991 also does not result in the reported <br />averages. What figures were used to obtain the averages and deviations? <br />e. Section I.B.l.b., short term average, provides explanations for TDS values which <br />aze outride the predicted average. 1984-1985 values aze attributed to rapid snow <br />melt in 1984 and 1985, and heavy rainfall in 1985. Please provide documentation <br />which corroborates those statements. <br />Elevated TDS levels in 1989 were attributed to an unusually slow snow melt. <br />Outside input is also mentioned as a possible contributor. Please provide <br />documentation for those events, as well. <br />It is not cleazly understood how both rapid snow melt and unusually slow snow <br />melt would have the same effect on TDS levels. Please provide additional <br />information. <br />f. Section I.B.2., monthly TDS levels, mentions elevated levels in July of most years. <br />The statement that "it is believed that the predicted monthly values for late <br />summer-early fall TDS levels may be influenced by input upstream" should be <br />substantiated. What upstream inputs would have influenced these TDS levels? <br />Over the next permit term, it might be advantageous to observe and make note <br />of upstream activities which might affect water quality at or below mining <br />activities. <br />g. Section II, the conclusion, compazes the 1981-1991 monitoring results for ground <br />water and the 1981-1992 results from surface water monitoring to the predicted <br />levels. Are the 1990 and 1991 results included in these comparisons? If data <br />from those yeazs has been discredited, it should not be used to indicate <br />conformity with predictions in the PHC. <br />h. Statement 1., explaining inconsistencies between measured and predicted TDS <br />levels, states that the original predictions were made for long term postmining <br />Susan Hoffineister 2 January 04, 1993 <br />