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59, Continued) The revised Table 2-1 does not include NPLs for surface water compliance monitoring sites as requested. Please propose NPLs for all surface water compliance monitoring sites. RESPONSE. Surface water quality standards are developed by the Water Quality Control Commission for specific segments of streams based on use classifications per Regulation 32, Classifications and Numeric Standards for the Arkansas River Basin (5CCR-1002-32). There are specific in-stream water quality standards developed for Arequa Gulch and Fourmile Creek that are specified in Colorado Discharge Permit System (CDPS)permits CO-0043648 and CO-0024562, respectively. CC&V does not have permitted surface water discharges in the other drainages, therefore, numeric effluent limitations do not exist in the Beaver Creek or Wilson Creek drainages. For these drainages, where no discharge is occurring, but a surface water compliance monitoring point exists (i.e., Beaver Creek and Wilson Creek), Newmont proposes the following NPLs using hardness-based and numeric table value standards as presented in Regulation 32. These values will be added to Table 2-1 in the Hydrology Report. Table 2-1 Numeric Protection Levels for Surface Water Monitorin Points Sulfate,Total Manganese, Zinc, Weak Acid Surface Water (mg/I as Dissolved Dissolved Dissociable Drainage SO4) pH (µg/I) (119/1) Cyanide, mg/I Arequa Gulch WQBELs—See CDPS No.CO-0043648 Beaver Creek 250 6.5 -9 2600 420 0.005 Wilson Creek 6.5 -9 2133 245 0.005 Fourmile Creek Flow-based WQBELs—See Carlton Tunnel CDPS No.CO-0024562 Note — only Beaver Creek, the receiving stream for Grassy Creek, is classified as a water supply and therefore only this location would have a NPL for sulfate, which is a secondary drinking water standard. Similarly, Beaver Creek would have a secondary drinking water standard for Manganese of 50 ,ug/l, however, historic data suggests ambient concentrations of Manganese in Grassy Creek and surrounding drainages are consistent with a hardness-based value of 2600 ug/l. The remainder of the drainages are either Use Protected with specific numeric limits andlor lack the water supply classification. Therefore, there is no sulfate standard listed. 59, Continued) The Division requires the Operator to propose NPLs for all compliance monitoring wells and surface water monitoring sites. Please be advised the Division's approval of AM-11 would not constitute a permanent approval of the NPLs presented in AM-11. Pursuant to Rules 6.4.21(9)(c) and 6.4.21(11)(c), the analytical detection limits and water quality parameters must be acceptable to the Division. The Division reserves the right to review and modify NPLs for any compliance water monitoring locations subsequent to the approval of AM-11. RESPONSE. Comment is acknowledged. Newmont understands that the Division may require modifications for points of compliance. Page S of 8