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tabulation of the mine water discharges and chemical analysis of <br />• those discharges is included as Table 1. Additionally, a <br />tabulation of monthly water balance at each mine is included as <br />Table 2. <br />Source of Water Inflow <br />As detailed in previous reports, the water flowing into the mine <br />seems to be a mix of water infiltrating the graben along the <br />faults and that water which is stored in the aquifer. Previous <br />years reports have detailed the process of determining the zone of <br />saturation in the local aquifers as well as the existance of a <br />perched aquifer in the mine area. Salt Creek belives that most of <br />these assumptions and conclusions are still valid. <br />In the past, the water flowing into the mine was probably a mix of <br />water from the perched aquifer and surface water infiltration <br />along the faults east and west of the mine. A system purely <br />dewatering the local perched aquifer would show no relationship <br />between water inflow and variations in seasonal precipitation. If <br />surface water infiltration were the only source of water, the <br />amount of water discharged from the mine would vary with amount of <br />precipitation received during different seasons of the year. As <br />Figure 2 shows, the amount of water being discharged from the mine <br />has decreased each year with some response to seasonal <br />precipitation. The inflow of water seems to have stabilized for <br />the last two years at about 50,000 gallons per month. <br />• Stabilization of inflows indicates that the drawdown cone in the <br />perched aquifer has reached equlibrium and that most of the inflow <br />to the mine results from surface water infiltration. <br />Further evidence of the cyclical nature of mine water inflows is <br />presented in Figure 3. This graph shows the average monthly <br />precipitation from 1977 thru 1986 and the average monthly inflow <br />of water (divided by 50,000) since 1982. The graph shows a high <br />degree of correlation between the two. Fluctuations in the early <br />part of the year may be attributable to the frequency of pumping <br />by mine personnel and the fact that precipitation during this time <br />of the year is in the form of snow. <br />Probable Hvdrologic Consequences <br />The McClane Canyon Mine seems to be dewatering a local perched <br />aquifer whose extent is not known and discharging water from <br />surface water infiltration. The bedrock aquifer has little if any <br />. direct communication with the alluvial sediments near McClane <br />Canyon and would not contribute significantly to the amount of <br />water in these sediments since the formation dips away from them. <br />Any contribution could only occur if the perched aquifer were <br />filled to capacity. McClane mine has created a new void for the <br />water to fill in the graben and is probably intercepting surface <br />water infiltration to the aquifer in the mine area. The <br />• intercepted water is then pumped to surface and discharged. <br />Therefore, Salt Creek is only modifying the means by which the <br />water is discharged and no significant harm is being done to the <br />