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LJ There were eight chromium values that had elevated detection limits higher than the acute and chronic standards. The cause of these elevated detection limits was a decision by the laboratory to dilute the samples prior to analyses in order to reduce the effects of interferences (primarily, high salinity). Finally, all mercury values reported were less than the most sensitive available detection limit, 0.2 ug/1. The standard for mercury is 0.01 ug/1. Surface Water Summary. Water discharged from the Seneca II Mine is not used directly for irrigation. Indirectly, although, water discharged from the mine is significantly diluted by water from either Fish Creek or the Yampa River before it is diverted and used for irrigation. No irrigation exists on Grassy Creek below Seneca II. Due to the relative amount of dilution by additional water from both sources, the ambient water qualities of Fish Creek and the Yampa River are the dominant factors in determining their suitability for irrigation. Water discharged from the Seneca II Mine is, however, used for livestock watering. Below average rainfall and snowfall values resulted in below average discharge values this year. TDS values at NPDES 002 and 003 are increasing at a moderate rate while TDS values at NPDES 004 and 008 are increasing slightly. On lower Grassy Creek (SSG2), TDS values are increasing slightly. Of the nine spoil springs monitored, six are exhibiting decreasing EC trends, while one displays a stable EC trend. Discharges are normally suitable for livestock, but sometimes exceed water quality standards for irrigation and aquatic life. No exceedences of NPDES effluent criteria (Permit No. CO-0000221) occurred this year. American Public Health Association (Ed.). 1985. "Standard Methods for the Examination of Water and Wastewater", 16th Edition, Washington, D.C. 24