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' Mazch 2, 1994 -4- 933-2714 <br />'~ and dissolved), lead (total and dissolved), zinc (total and dissolved), sulfate, conductivity, <br />total dissolved solids and pH. <br />,` The recent sampling was done when baseflow conditions in streams existed. There was <br />variable snow cover up to about 8 inches in the azeas sampled. Willow Creek was frozen <br />over in most places. Water was dischazging from the Nelson Tunnel but the flow rate could <br />not be estimated. No water was flowing in Windy Gulch. <br />' Results from the sampling round are plotted in the graphs included in Attachment 5. Plots <br />are presented for each constituent with concentration on the vertical axis and station on the <br />' horizontal axis. Stations are plotted from upstream on the left to downstream on the right. <br />Attachment 6 includes a copy of the laboratory report from this sampling round. <br />Detectable concentrations of cadmium, lead and zinc were measured at all stations. Copper <br />and iron were below detection at all stations except directly below the Nelson Tunnel <br />(WCBNT). <br />' Total and dissolved metals concentrations were lowest above the Nelson Tunnel (station <br />WCANT) and highest directly below the Nelson Tunnel (station WCBNT). Concentrations <br />of metals at downstream stations were lower than the station duectly below the Nelson <br />' Tunnel, probably because of dilution from East Willow Creek. Metals concentrations above <br />and below Windy Gulch (stations WCAWG and WCBWG) were essentially identical <br />indicating no detectable contribution of metals from groundwater in the Windy Gulch azea. <br />' In general, there was a slight increase in metals at the station below Creede (WCBC) except <br />in lead which decreased. <br />' Sulfate was lowest in WCANT and highest in WCBNT. Concentrations at WCAWG and <br />WCBWG were essentially identical indicating no detectable sulfate loading from the Windy <br />Gulch area. Sulfate increased significantly at WCBC. Conductivity and total dissolved <br />solids followed the same pattern as sulfate. <br />' pH decreased from WCANT to WCBNT and then increased at WCAWG and WCBWG. <br />The station below Windy Gulch was slightly higher than the station above the gulch. pH <br />decreased at WCBC. <br />t Conclusions <br />' Review of the site topography, geology and hydrogeology indicates that groundwater will <br />not flow from the Bulldog Mine to the Nelson Tunnel. The Nelson tunnel derives flow <br />from the extensive interconnected underground workings in mines along West Willow Creek <br />' which aze hydraulically upgradient of the Bulldog workings. The Bulldog Mine workings <br />are along a different fault zone than the Commodore working and are not interconnected <br />with the Commodore workings. <br />1 <br />1 <br />