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of 0.262 mg/l. However, as indicated in CWQCC Regulation 31, the standard of 0.2 mg /l <br />applies to plants grown in acidic ( <6.0 pH) soils. In alkaline soils, as found in the Seneca II <br />Mine ermit area, a more appropriate standard is 10 mg/l. <br />Permit Requirements of the Colorado Discharge Permit System (CDPS) <br />The Seneca II Mine maintains one outfall, Pond 008 (NPDES8) that is monitored under the <br />CPDS Permit No. CO- 0000221. Sample data was collected and reviewed for all required <br />parameters and sample analysis included testing for Whole Effluent Toxicity. Sample data has <br />been reported on a quarterly basis in discharge monitoring reports filed with the CDPHE and the <br />CDRMS. These DMRs indicate that no exceedances of permit limits have occurred in the past <br />three water years. <br />Clean Water Act Effluent Limitations (40 CFR Part 434) <br />Monitoring data for the past three years indicates the Seneca II Mine has not caused exceedances <br />of either limitation identified in 40 CFR Part 434 that is applicable to reclamation areas on coal <br />mines (settleable solids of 0.5 ml /1 and pH of 6.0 to 9.0). Seneca II Mine only notes settleable <br />solids values that are at or above the detection limit of 0.4 ml /1, no exceedances of 0.4 ml /1 were <br />noted. <br />Impacts to Alluvial Valley Floors (AVFs) <br />The Seneca II Mine conducted an impact projection analysis as noted in Tab 7, Section VII.A. Lc <br />in C- 1980 -005. The analysis concluded that total dissolved solids (TDS) increase in the Fish <br />Creek stream flow as a result of surface water discharges from NPDES8 on the order of 76 mg/1 <br />for the months of June and July. The projection equates to TDS concentrations in the Fish Creek <br />streamflow ranging from 497 to 607 mg/l. <br />Based on a demonstration provided in Tab 7, Section VII.B. Lc, crops grown in the area of <br />alluvium can tolerate TDS concentrations in excess of 2,000 mg/l. Predicted TDS concentrations <br />of Fish Creek streamflow of only 497 to 607 mg/l will not result in water quality changes that <br />significantly and adversely affect the composition, diversity or production of the vegetation <br />dependent on subirrigation. Water quality data for June and July at Sites SSF11 and SSF13 from <br />2003 to 2013 show that the maximum increase of TDS between the sites was 50 mg/1 in June (a <br />74 mg /1 increase was predicted) and 70 mg /1 in July ( a 74 mg /1 increase was predicted). TDS <br />increases on Fish Creek due to the Seneca II Mine are not causing significant negative impact to <br />potential crops in the area. <br />Based on the review of the water monitoring data for the Seneca II Mine, the observed <br />hydrological impacts are consistent with those predicted in the PHC section of the permit, C- <br />1980 -005. Although the 4.6 ug /1 selenium standard was exceeded at NPDES8, this standard is a <br />"Report" only based on the requirements of CO- 0000221 and the receiving stream standard for <br />selenium has not been exceeded at any of the downstream monitoring sties. Water pollution is <br />not occurring at the Seneca II Mine and, based on a review of the monitoring data and on the <br />