2011-09-16_APPLICATION CORRESPONDENCE - C2010089 (2)

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C- 2010 -089 PAR No. 2A New Horizon North Mine Sincerely, 16- Sep -2011 Page 2 of 2 Rule 2.05.6(3)(b)(iv)requires that the operator have a hydrologic monitoring plan in place to determine the impact on the hydrologic balance. Under Rule 2.05.6(3)(b)(iv)(D), the Division can require the monitoring of additional water quality parameters in this hydrologic monitoring plan if warranted by site - specific conditions and for good cause shown. The chemical analyses for overburden, interburden and underburden presented in Appendix Table 2.04.6 -2 show that some of these metals are in the rocks, although chromium, cyanide, nickel and silver were not sampled. The Division believes that, because these heavy metals have receiving stream standards and because these heavy metals are present in the rocks at the New Horizon North Mine, the surface water monitoring program should include these chemical constituents. Likewise, the Division's Guidelines for the Collection of Baseline Water Quality include arsenic, cadmium, manganese, mercury, and zinc (dissolved species) and these were not included in the Water Quality Parameter List for groundwater. Further these constituents are included in the Basic Standards for Groundwater (Tables 1 and 3). The Division believes that these constituents should also be included in the approved water monitoring program for groundwater. Also, at the time of bond release, Rule 3.03.2(2)requires the Division to make an evaluation that surface or subsurface water pollution is not occurring. Therefore, all relevant chemical parameters need to be included in the water monitoring program. Please include these chemical constituents in Table 3 and in future surface water and ground water sampling or justify the omission of these heavy metals in the surface water and ground water parameter list . Also, please ensure that the species for each chemical parameter is included in Table 3 and is the species that is monitored. The ground water parameters include both total and dissolved species for some constituents. For surface water parameters, each species should be consistent with the species listed for the San Miguel River stream segment 12 in Regulation No. 35 of the CDPHE Water Quality Control Commission's "Classifications and Numeric Standards ". The interne address is: http: / /www.cdphe. state. co. us /op /wqcc /Standards /RegsCurrent /35 2011(06)tables.pdf Please contact me if you have any questions regarding these additional issues. Sandra L. Brown Sr. Environmental Protection Specialist cc: Marcia Talvitie