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• <br />Comprehensive Analytical Results Reporl <br />Fast and West Willow Creek <br />Solomon and Mammoth Tunnels on East Willow Creek also exhibit significantly elevated concentrations <br />of several analytes. <br />Metals concentrations in West Willow Creek increase dramatically below the Nelson Tunnel, however, <br />loading analyses reveal that only a small portion of this increase can be attributed to the Nelson Tunnel. <br />Thirty-eight surface water and collocated sediment water samples were collected for this investigation. <br />Stream flow measurements allowed for metals loading calculations for all surface water and aqueous source <br />locations. Elevated concentrations for aqueous surface water samples are noted for 10 analytes at one or <br />r _ <br />` ~ are the primary metals of concern for aquatic life. These metals aze widespread and are frequently present <br />~ .,-' at concentratiotu which greatly exceed the Ambient Water Quality Criteria for surface waters found in the <br />mare locations for dissolved metals and for 12 analytes at one or more locations for total metals. For total <br />I'! metals there are 98 instances in which elevated analyze concentrations occur. Cadmium, lead, and zinc <br />~~ Superfund Chemical Data Matrix (SCDMs) (Cadmium 1.1, Lead 3.2, and Zinc 110, values in micrograms <br />per liter). In addition, the Table Value Standards adopted by the Colorado Water Quality Control <br />=~ <br />~ Commission for sections of East Willow Creek and the Rio Grande River are exceeded for lead and for <br />• zinc. Sediment samples exhibit elevated concentrations for 12 metals at one or more locations for a total <br />of 160 occurrences. <br />West Willow Creek samples exhibit elevated metals concentrations beginning at the Amethyst Mine. A <br />significant increase in metals loading along West Willow Creek occurs near the Commodore Mine and <br />Nelson Tunnel where total cadmium concentrations increase from 5.5 micrograms per liter (µg/1) to 294 <br />µg/l, total lead concentrations increase from 13.5 to 465 µg/I, and total zinc increases from 348 to 19,900 <br />µg/l. The dissolved zinc load carried by West Willow Creek increases from 46.66 pounds per day (ppd) <br />above the Commodore and Nelson Tunnel to 185.75 ppd below. Most of the increase is due to diffuse <br />sources and utueen ground water to surface water flows because the Nelson Tunnel discharge contributes <br />less than 8 ppd to this load increase. <br />Windy Gulch surface water release samples, located downstream from the Bulldog Mine exhibit elevated <br />concentrations for a number of analytes. Loading analyses indicate that Windy Gulch is contributing <br />approximately 24 percent of the dissolved zinc load in Willow Creek which increases from 258.57 ppd <br />above Windy Gulch to 319.94 ppd below. <br />14 <br />