2013-12-31_REPORT - C1982057 - Laserfiche WebLink

Home Browse Search

Page 3 of 5 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 ten times at nine different sites. 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 1.85 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 2012 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 four times at three sites, with no NPDES exceedances for iron occurring during the 2012 water year. The chronic selenium standard of 4.6 ug /I was exceeded twice at NPDES17 (5.0 and 11.6). 10. Interim Narrative CWQCC regulation It was determined that bed rock groundwater points of Standard for Ground Water 41.5.C.6 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 ambient -based standard for iron (8.06 mg /1) was exceeded with a value of 10.6 mg /1. Well DCAL -02 did not exceed the TDS standard, 3195 mg /1. 11. Sampling frequency Appendix 15 -3a, Table 1 The report indicates that all frequencies were met. surface water of CDRMS mining permit C- 1982 -057 12. Parameters to be Appendix 15 -3a, Table 2 Parameters to be sampled are conductivity (umhos /cm), pH sampled at surface water of CDRMS mining permit (units), temperature (C), total recoverable iron (mg /1), sites C- 1982 -057 dissolved manganese (mg /1), total mercury (ug /1), dissolved nitrate (mg /1), dissolved nitrite (mg /1), total ammonia (mg /1), dissolved selenium (ug /1), dissolved sulfate (mg /1), total sulfide (mg /1), total suspended solids (mg /1) and total dissolved solids (mg /1). All required parameters were analyzed. All parameters were met. 13. Filing frequency of pond CDRMS regulation Ponds 005, 006, 009, 015, 016, and 017 are the sediment reports 4.05.9(17) pond associated with C- 1982 -057. Quarterly pond inspections were conducted within the appropriate quarter.