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well. Statistically significant increasing TDS trends are observed. Surface Water SPL has a functioning sediment control system diverting, conveying and/or treating surface water runoff in and around the mine site. The sediment control system includes seven sedimentation ponds (Ponds 005, 006, 009, 015, 016, 016A and 017). A more complete discussion of this system is found above, in Section III C of this document. The applicant conducts monitoring of surface water in a manner approved by the Division. The monitoring plan submitted under 2.05.6(3)(b)(iv) comprises Tab 15 and Appendix 15- 3A of the permit application package. A number of amendments to the surface water parameter list and analytical techniques for certain parameters were approved in TR69, in 2010 and TR83 in 2016. SPL included a plan for an alternative water supply in the event that local water rights are adversely impacted by mining in Tab 16 of the permit. Hydrologic protection,probable hydrologic consequences, and the hydrologic reclamation plan constitute Tabs 16, 17,and 18,respectively. Surface water at the Seneca IIW Mine lies within two watersheds. The primary affected area lies within the Dry Creek Drainage flowing to Hubberson Gulch and an unnamed tributary to Dry Creek (the Pond 005 Gulch). A small portion of the eastern part of the permit area drains to Sage Creek. Both creeks confluence with the Yampa River near Hayden. Both Dry Creek and Sage Creek exhibit intermittent to perennial flows, depending on location along the streams, and precipitation trends. Hubberson Gulch is intermittent. Surface water quality sampling is described in Tab 15,Appendix 15-3A of the Seneca IIW mining permit. The CDPHE surface water quality and receiving stream standards appropriate for the site are: o CDPHE,Regulation 31,2009 o Yampa Segment 13d,Regulation No 33,2015 o Yampa Segment 13e,Regulation No 33,2015 The stream standards for Sage Creek and Dry Creek are based on aquatic life standards. Occasional annual exceedances comprise ammonia nitrogen MDL,mercury, sulfide and the recoverable iron standards. The recoverable iron standard has seasonal limits(1.I I mg/1 from May—Feb. and 3.04 mg/1 during March and April). The high level mercury test with a method detection limit of 0.2 ug/1 for streams was run as were tests for ammonia nitrogen and sulfide. All high level test values were less than the detection limits. Based on CWQCC reg. 31,the manganese standard of 0.2 mg/l,applies to plants grown in acidic soils(<6.0 pH). In alkaline soils,as found throughout the Yoast and Seneca II W region,the EPA standard would be 10 mg/l. Pre mining manganese baseline values exceeded the 0.2 mg/1 standard. The manganese standard(0.2 mg/1),for agricultural use, is generally exceeded a couple instances per year. This standard is only appropriate where irrigation is utilized on soils with a pH lower than 6.0. In the alkaline soils typical of the Seneca II site,a more appropriate standard would be 10 mg/L,thus the 0.2 mg/1 standard shows occasional annual excursions. The Hubberson Gulch Watershed,Dry Creek and Sage Creek 11 monitoring sites exist within the Sage Creek, and Hubberson Gulch/Dry Creek basins. These include six NPDES surface water monitoring sites. In TR63 it was determined that Page 21 of 37