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4. i-= r. .Srr_...<.....rw....iwau.r..w.—..a......r..i.re..a...._.. ♦_�_a ..�.. _ _ <br /> AMERICAN TUNNEL AREA: <br /> (1 ) Cement Creek (CC-1 , CC-2) , Table 5. <br /> Durina the past CC1 , Cement Creek above the mine, was not <br /> sampled during winter months because of access problems . <br /> This year Cement Creek was sampled when possible immediately <br /> upstream from the mine discharge during those months when <br /> CCl was inaccessible to provide data on creek quality year <br /> around. The site has been identified as CC1 . 5 and while it <br /> is not technically upstream from the mine property it will <br /> give information for comparison purposes with CC2 . <br /> A sampling site has also been identified on Cement Creek in <br /> Silverton (CC Town) -upstream from the Greene Street Bridge <br /> for information purposes . This site will be monitored on a <br /> monthly basis for as long as the company finds it <br /> worthwhile . <br /> Cement Creek above the mine continues to be of very poor <br /> quality with pH values ranging from around 3 units in the <br /> spring and summer up to 6 units in the late fall . Various <br /> dissolved metals particularly zinc and aluminum are high <br /> also. Cement Creek below the mine shows an improvement in <br /> quality from the mine discharge AT0O4 . Amount of <br /> improvement depends on flow ratios and alkalinity and <br /> acidity levels in CC1 . CC Town generally shows a decrease <br /> in quality from CC2 . <br /> ( 2) American Tunnel Waste Pile Seeps (ATS-1 , ATS-2) , Table 6. <br /> Flow from the slotted drain pipe at the toe of the dump was <br /> monitored on a monthly basis during the summer months . The <br /> drain appears to be collecting all water formerly coming to <br /> the surface. Most of the water is flowing from the South <br /> side drain and the center of the pile at ATS2 . The North <br /> drain was frequently not flowing. Water data shows poor <br /> quality water with high dissolved solids and metal levels. <br /> The site will continue to be monitored on a monthly basis <br /> the sum-per of 1991 and lab work will be done to investigate <br /> such treatment options as ion exchanee, Biofix Beads and/or <br /> diversion to existing treatment ponds. <br /> TERRY TUNNEL AREA: <br /> Eureka Creek (EC-1 ) , Table 7. <br /> Eureka Creek above the Terry Tunnel showed no unusual water <br /> quality data. Total Suspended Solids was down from the year <br /> before probably reflecting decrease in road traffic. <br /> - 10 - <br />