2014-05-19_REPORT - C1982057 - Laserfiche WebLink

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Page 2 of 5 Quality Control Division (WQCD), the WQCD will be responsible for enforcing CDPS permit conditions. 8. Basic Standards for CWQCC regulations Only sites WSDS, WSSF3, WSH7, and WSHF1 downstream of Surface Water 31.1.11 the Seneca II -W site have their waters used for irrigation. Only the CDPHE surface water agricultural use standard for manganese was exceeded. The manganese standard was exceeded eleven times at ten different sites, including Springs WSPG46, 50, WSSPGI, 3, 4, and 5. Based on CWQCC reg. 31, the standard of 0.2 mg /1, applies to plants grown in acidic soils ( <6.0 pH). In alkaline soils, as found throughout the Youast and Seneca II W region, the EPA standard would be 10 mg /1. The maximum manganese value observed at any surface site was 1.28 mg /I at Spoil Spring 3. Pre - mining manganese baseline values exceeded the 0.2 mg /I standard. 9. Instream Numeric CWQCC regulation 33.0 Eleven monitoring sites exist within the Sage and Dry Creek Standards Basins: NPDES 15, NPDES 9, and WSSF3 are on Sage Creek. NPDES 17, NPDES 16, NPDES 6, NPDES 5, WSH9, WSH7, WSHF1, and WSDS are on Dry Creek. The receiving stream standards for Sage Creek is on Segment 13e of the Yampa River and Dry Creek is on Segment 13d of the Yampa River basin. The stream standards for Sage Creek and Dry Creek are based on aquatic life standards. Table 12 of the 2013 AHR provides a comparision of the standards to water quality collectedfrom NPDES points and stream sites in the Sage and Dry Creek Basins. The total recoverable iron standard (1.0 mg /1) was exceeded five times at five sites, with one NPDES exceedance for iron occurring during the 2013 water year (see Item 8). 10. Interim Narrative CWQCC regulation 41 The ground water standards for agricultural use for Standard for Ground Water manganese was exceeded four times at four sites (DCAL -02, WHAL 7 -2, WOV14, and WW14). Based on CWQCC reg. 41, the standard of 0.2 mg /1, applies to plants grown in acidic soils ( <6.0 pH). In alkaline soils, as found throughout the Youast and Seneca II W region, the EPA standard would be 10 mg /1. The maximum manganese value observed at any surface site was 1.57 mg /1. The iron standard (5.0 mg /1) was exceeded three times at three different sites (DCAL -02, WTC201, and WW14). It is noted that the highest level of iron recorded in spoil springs within the Seneca II -W permit was 0.34 mg /1. The pH standard (8.5 max) was exceed at WWCU25 with a value of 8.71. It was determined that bedrock groundwater points of compliance are unwarranted at the Seneca II -W Mine. Well DCAL -02 serves as the Seneca II -W Mine's Dry Creek Alluvial ground water point of compliance. One exceedance of the