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iron (CDOH, GW, irrigation) 2 manganese (COON, SW, irrigation) 11 • nickel (CDOR, SW, irrigatron) 1 dissolved solids (U SE PA, irrigation) 20 dissolved solids (Wyoming, livestock) 1 sulfate (California, irrigation) 21 Review of this table indicates that only two CDOH surface water agricultural use standards were exceeded. Nickel was exceeded at Spoil Spring 6 (SSSPG6). tloweves, thin water is substantially diluted before it leaves the permit boundary (notice no exceedences at lower Grassy Creek (S SG21). The manganese standard was exceeded at eleven sites. tloxevex, as noted previously in the ground water discussion, the relatively lox standard of 0.2 mg/1 applies to plants grown in acidic soils. In alkaline soils, as are found in the Seneca II region, a more appropriate standard would be 10 mg/1. With the exception of Spoil Spring 6, the maximum manganese value observed this year was 1.43 mq/1 at 3poi1 Spring 10 (SSSPGI0). Spoil Spring 6 had a manganese value this year of 11.6 mg/1. tloxevex, as stated previously in Chia paragraph, water from this spring is diluted before leaving the , mine site. All other surface water sites and springs had manganese values less than 1.0 • mg/1. It should also be noted that the sites on Grassy Creek (SSG1) and Fish Creek (SSF11),' that axe upstream of Seneca II discharges, also experienced exceedences of the 0.2 mg/1 standard. Water discharged from the Seneca II Mine ie not used directly for irrigation. Indirectly, although, wa ter discharged from the mine is significan tly diluted by water from either Fish Creek or the Yampa River before it is diverted and used for irrigation. No irrigation exists on Grassy Czeek below Seneca II. Due to the relative amount of dilution by adtlitional water from both sources, the ambient water qualities of Fish Creek and the Yampa Aiver are the dominant Factors in determining their suitability for irrigation. water discharged from the Seneca II Mine is, however, used for livestock watering. Surface Water Summary. Nearly normal rainfall and snoxfall values resulted in nearly normal discharge values this year. TDS values at NPDES 004 and 00R are increasing at a moderate rate while TDS values at NPDES 002 and 003 are increasing slightly. On lower Grassy Creek (SSG2), TDS values display a very slightly increasing trend. Discharges are normally suitable For livestock, but sometimes exceed water quality standards far IS