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<br />West Elk Mine 2001 Annual Hydrology Report <br />analysis was conducted to assess the potential cumulafive hydrologic impacts of mining and other <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 acflvities. <br />The CHIA assumed that MCC's contribution to the North Fork would be 1,000 gpm with a TDS <br />concentraflon of 2,500 mg/1. The total WY2001 dischazge from the Project was approximately 714 <br />gpm. The flow weighted maximum annual TDS load from the Project was 2,837 tons. This is <br />about 50 percent below the value used in the CHIA. A summazy of the salinity loading from the <br />mine 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) ( 1) (tons/ ear) <br />WY2001 714 1,920 2,837 50 <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 hydrogcaphs aze presented <br />in Appendix D, and flow and water quality data aze in Appendix E. <br />5.2.1 Water Quantity and Quality <br />• <br />Spring and seep flows in WY2001 were below normal due to below normal snow pack and <br />precipitation. A number of sites that typically flow were dry or had no measurable flow in <br />WY2001 including: G-16, G-22, G-24 and CR-12. Springs G-16, G-22, and G-24 aze all in the <br />Sylvester Gulch drainage and are likely affected by lowering ground water levels due to continued <br />drought conditions. There is no indication that the reduced flows were the result of mining <br />activities. <br />Water quality data from WY2001 did not indicate changes from baseline condiflons for any of the <br />monitored springs with the exception of spring G-7. The dissolved and total iron concentrations <br />measured from G-7 exceeded the baseline maximum values. Dissolved iron concentration <br />measured in WY2001 was 0.34 mg/1 compared to the baseline maximum of 0.07 mgQ. The total <br />iron concentration was 1.16 mg/1 compared to the baseline maximum of 0.4 mg/l. Other tested <br />parameters were neaz baseline concentrations. The elevated iron concentration is likely due to <br />Prajwt # 00301 <br />24 <br />HydroGeo, Inc. <br />