Laserfiche WebLink
samples prior to analyses in order to reduce the effects of <br />interferences (primarily, high salinity). Finally, all mercury values <br />reported were less than the most sensitive available detection limit, <br />0.2 ug/l. The standard for mercury is 0.01 ug/1. <br />Surface Water Summary. Water discharged from the Seneca II Mine is not <br />used directly for irrigation. Indirectly, although, water discharged <br />Erom the mine is significantly diluted by water from either Fish Creek <br />or the Yampa River before it is diverted and used for irrigation. No <br />irrigation exists on Grassy Creek below Seneca II. Due to the relative <br />amount of dilution by additional water from both sources, the ambient <br />water qualities of Fish Creek and the Yampa River are the dominant <br />factors in determining their suitability for irrigation. Water <br />discharged from the Seneca II Mine is, however, used for livestock <br />watering. <br />Below average rainfall and snowfall values resulted in below average <br />discharge values this year. TDS values at NPDES 002 and 003 are <br />increasing at a moderate rate while TDS values at NPDES 004 and 008 are <br />increasing slightly. On lower Grassy Creek (SSG2), TDS values display a <br />stable trend. Of the nine spoil springs monitored, three are exhibiting <br />decreasing EC trends, while four display a stable EC trend. Discharges <br />are normally suitable £or livestock, but sometimes exceed water quality <br />standards for irrigation. <br />No exceedences of NPDES effluent criteria (Permit No. CO-0000221) <br />occurred this year. <br />References <br />American Public Health Association (Ed.). 1985. "Standard Methods for <br />the Examination of Water and Wastewater", 16th Edition, Washington, <br />D.C. <br />Brakensieh and others. 1979. "Field Manual for Research in <br />Agricultural Hydrology". <br />22 <br />