2011-12-28_APPLICATION CORRESPONDENCE - C2010089

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Page 8 of 9 25. A) According to permit text page 6 of Section 2.05.6(3), surface water monitoring site SW -N206 was destroyed and, therefore, does not appear in Table 2 on page 2 of Appendix 2.05.6(3) -3. However, the site still appears on Map 2.04.7 -1. In order to avoid any confusion, please add a note next to the site on the map to show that the site was destroyed and the year it was destroyed. The Division has no further concerns. Map 2.04.7 -1 was revised appropriately in the submittal dated November 29, 2011. B) The CDPHE receiving stream standards for Segment 12 of the San Miguel River include standards for certain heavy metals that do not appear in the surface water baseline data of Appendix 2.04.7(2) or in the operational monitoring program presented in Table 3 of Appendix 2.05.6(3) -3. These heavy metals include arsenic, boron, cadmium, chromium III, chromium IV, copper, cyanide, mercury, nickel, silver, uranium and zinc. 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 internet address is: http: / /www.cdphe. state. co. us /op /wqcc /Standards /RegsCurrent /35 2011(06)tables.pdf The Division has no further concerns. Appendix 2.05.6(3) -3 was revised accordingly in the submittal dated November 29, 2011. B) There are several spoil springs and surface water monitoring sites that are associated with previous mining that, according to the permit text, will be used or reactivated to monitor the effects from the New Horizon North Mine. Please add these additional water monitoring sites to the tables in Appendix 2.05.6(3) -3 if they are part of the New Horizon North Mine water monitoring program. Also, the