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<br />Page 65 .. It is unclear what the design "sustained flow rate" for a dewatering system would be <br />after removal of the initial heads. Page 65 bullet 6 indicates a long ternt dewatering rate of 100 <br />GPM, the next page suggests a long term rate of 110 GPM, and both rates are apparently based <br />upon an initial steady state assumption of 80 GPM under current conditions. It does no[ appear <br />that either of these assumptions consider inflow from the alluvium on the southeast side of the <br />pi[, and [he increase in this flow with the increase in gradient which will result from lowering of <br />the water level in the pit. <br />Page 66, paragraph 6.1.2 .. If an enhanced evaporation system is adopted, the augmentation plan <br />covering the mine will need to be continued, or amended as appropriate to protect downstream <br />senior rights. <br />Comments on West Pit Hydrogeologic Characterization. Aaoendix A <br />The "Characterization" report presents information collected during the hydrogeologic <br />field studies, and provides an interpretation of this data. <br />Water Levels .. <br />There aze a number of changes in water levels reported in Table A-2 that bring the issue <br />of steady state conditions into question. Well SF-1, apre-existing well, sees water level <br />variances of about 10 feet over the short period of record. Well SF-2 sees a water level decline <br />of 83 feet and a rise of 102 feet a few days later. We anticipate [here was something going on in <br />the well during this period, but some explanation is needed. Other wells, M-18, M-19, M-22, <br />M-23, M-25, M-26, and M-27 also show significant water level changes over the short period of <br />record. It is unclear if these are due to dewatering, well testing, or are a natural condition in the <br />aquifer. The data for well SF-4 cannot be effectively used as there is no datum associated with <br />[he water levels. Well SF-5, [he well directed [o be constructed by MLRB has no water level <br />data presented [hough the drilling discussion suggests the well did have water in it. <br />Aquifer Tests .. <br />A number of questions arise with regard to the aquifer tests as follows: <br />Comments on Table A-3 <br />Table comment for well M-29 indicates "Pumps used for testing were either too <br />small or too large to effect an appropriate drawdown response." It's uncleaz what <br />this means. <br />Well SF-5 is identified as a dry well on Table A-3, yet in [he text (page A-5, <br />pazagraph 4) it indicates the well was developed by surging, bailing, and <br />pumping. This doesn't sound like a dry well. <br />