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West Elk Mine 2002 Annual Hydrology Report <br />• <br />activities in the North Fork Valley on the North Fork's water quality and flow. The CHIA analysis <br />determined that no significant hydrologic impacts were expected as a result of mining activities. <br />The CHIA assumed that MCC's contribution to the North Fork would be 1,000 gpm with a TDS <br />concentration of 2,500 mgJl. The total WY2002 discharge from the Project was approximately 284 <br />gpm. The flow weighted maximum annual TDS load from the Project was 1922 tons. This is <br />about 34 percent of the value used in the CHIA. A summary of the salinity loading from the mine <br />compared to the CHIA study is shown on Table 11. <br />Table 11 <br />Summary of Salinity Loading in the North Fork <br />• <br /> Average Maximum Flow Calculated <br />Scenario Continuous Weighted TDS Annual Salinity Percent of <br /> Discharge Rate Concentration Loading CHIA Loading <br /> m m 1 tons/ ear <br />WY2002 284 1887 1922 34 <br />1997 CHIA 1,000 2,500 5,670 -- <br />5.2 Springs and Seeps <br />MCC routinely monitors 24 springs and seeps, listed in Table 3. Spring hydrographs are presented <br />in Appendix D, and flow and water quality data are in Appendix E. <br />5.2.1 Water Quantity and Quality <br /> <br />Spring and seep flows in WY2002 were below normal due to below normal snow pack and <br />precipitation. A number of sites have been dry for over a year including G-26A, 15-1, 10-1, E-14- <br />1, Gla, 10-2, 11-2, and G-30. Several springs do not flow but are typically wet in the spring <br />season. These include G-24 and G-35. These springs have likely been impacted by lowing ground <br />water levels due to continued drought conditions. There is no indication that the reduced flows <br />were the result of mining activities. <br />Water quality data from WY2002 did not indicate changes from baseline conditions for any of the <br />monitored springs with the exception of spring G-7, 27-1, J-4, and G-49.. Most trace constituent <br />concentrations measured from G-7 and 27-1 exceeded the baseline maximum values. Springs J-4 <br />and G-49 had slightly elevated TDS levels in WY2002. These increased concentrations are likely <br />due to very low flow rates during the sampling period in June 2002 due to the drought and are not <br />believed to be related to mining operations. However, MCC will carefully watch the water quality <br />of this spring to see if any water quality trends occur. <br />Project # 00301 <br />25 <br />HydroGeo, Inc. <br />