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There is insufficient data to indicate that the wells are properly located such that an upgradient and downgradient station is situated near each monitored facility. Well completion details of these wells have not been submitted such that their effectiveness can be evaluated. Finally, background water quality data for wells in the processing area were not submitted. The operator needs to provide more information about the monitoring system. The operator should demonstrate that there is an upgradient and aowngradient well situated near all major features which could potentially adversely impact water quality. These features include the heap facility, tailings pile, waste rock pile which contains altered gneiss interburden, and the pit areas. I would recortunend fewer stations near the pit areas and more located around the processing areas and waste rock and tailings piles. Downgradient wells should be located as close as possible to the facilities they will monitor. Submitted data should include locations, well completion specifications with water levels, well construction and geologic logs for each well, and water quality data for all proposed monitoring wells. Reclamation of West Pit The hydrogeology of the west pit area appears to be complex. The orebody is a fractured mass of gneiss which appears to be surrounded and/or cut by numerous faults and fractures. The orebody is described to be an aquifer of limited extent and high porosity. The surrounding faults are described to be aquitards. A thrust fault mapped in the southwest portion of this pit creates a confining layer beneath which artesian conditions are present southwest of the pit area. Flow data in this confined aquifer were documented. The west pit will be reclaimed as an internally draining basin. Arly water which flows into the pit will drain towards the southwestern p~ on of the pit. The application states that pit dewatering will permane~ deplete the aquifer in this area, and therefore the pit will not fill wi-. =er after mining and reclamation are complete. It is expected that the ar,;cunt of water which enters the pit either through precipitation or seepage will he evaporated. There is insufficient data in the fiile to substantiate the prediction that the pit will not contain permanent standing water after reclamation. For example, there is insufficient information which shows how the pit design will intersect the faults and fractures, such that their influence on the hydrologic balance can be ascertained. The hydraulic characteristics of the unconfined portions of the orebody, surrounding country rock, and fracture zones are not well documented. It 9s likely that the horizontal and vertical extent of fracturing probably goes beyond the economically mineralized zone, based on geologic inference of other similar mineralized systems. Therefore, the extent of this fracture-controlled aquifer may also extend beyond the pit area. It is also unknown whether dewatering will cause a hydraulic gradient reversal in the alluvial aquifer in the vicinity of Rito Seco and thus provide an unanticipated source of ground-water flow from the south. Some of this information may be available in the exploration drill logs which were probably done during orebody delineation. However, it is likely that the amount of data needed to be certain of the dewatering hypothesis has not been obtained.