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1 <br />' MINE INFLOW MONITORING <br />The inflow to the underground mine is monitored in two ways. The flow rate and <br />' water quality of the discharge from the mine (Site 109) is monitored before it <br />enters Sediment Pond D, and an annual inflow study is performed. In the inflow <br />' study the flow rate and water quality of major inflows to the mine are measured. <br />The 1986 inflow study is presented in Appendix A. Additionally, small quantities <br />' of water are discharged from a sump area outside of the portal (Site 113). This <br />water is also discharged to Pond D. <br />Flows <br />A plot of flow rate verses time is presented on Figure 29. The data indicates <br />' that flow rate was fairly constant at approximately 0.2 cfs (90 gpm) from 1984 <br />through the first half of 1986. In the second half of 1986 the average discharge <br />rate increased to approximately 0.3 cfs (140 gpm). This increase appears to be <br />due to pi larina during this eriod. The discharge rate at the end of the year <br />was approximately 0.3 cfs (140 gpm). The discharge rate is at the high end of the <br />rate predicted for this period of mine development. The mine inflow study, <br />performed in December 1986, indicated that no single type of activity or location <br />' in the mine accounted for a majority of the discharge. No large inflow could be <br />attributed to a fault zone. The inflow study is contained in Appendix A. <br />Water Quality <br />Summaries of the water quality of Site 109 are presented on Tables 42 and 43. A <br />plot of dissolved solids of the mine discharge (Figure 30) indicates a large <br />amount of scatter in the data. This probably occurs because pumps from different <br />areas of the mine are operating at different times. Prior to the second half of <br />' 1986 the average dissolved solids level was approximately 2300 mg/L. In the <br />second half of 1986 the dissolved solids levels increased to approximately 2800 <br />' mg/L. This increase probably has occurred from the advancement of the front of <br />high dissolved solids water in the Wadge Overburden aquifer as indicated by the <br />198~1nv Studv The high dissolved solids in the Wadge Sump is occurring due <br />to seepage from the reclaimed spoil areas. <br />