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Table A-2 Standards for Stream Segment COARUA21 and 22a Changes in standazds that will be effective January 20, 2003 aze included in Parentheses Standard COARUA21 COARUA22a Free Cyanide acute 0.005 m 0.005 m Sulfide chronic 0.002 m 0.002 m Nitrite 0.05 m 0.05 m Dissolved Alumhzum acute and chronic NA 11,000 ug/I Total Recoverable Arsenic chronic 100 u 100 u Dissolved Cadmium acute and chronic TVS acute trout a lies TVS Total Recoverable Trivalent Chromium chronic 100 ug/1 100 ug/1 Dissolved Hexavalent Chromium acute and chronic TVS TVS Dissolved Copper acute and chronic TVS TVS Total Recoverable Iron chronic 1000 u I 1000 u 1 Dissolved Lead acute and chronic TVS TVS Dissolved Man ese acute TVS 18,500 u (5,903u ) Dissolved Man anew chronic TVS 6,300 u (3,674 u ) Total Mercu chronic 0.01 u 0.01 tt Dissolved Nickel acute and chronic TVS TVS Dissolved Seletuum acute and chronic TVS TVS Dissolved Silver acute and chronic TVS TVS Dissolved Zinc acute TVS 3,500 u Dissolved Zinc chronic TVS 800 u l (600 u Standards for metals aze generally shown in the regulations as Table Value Standards (TVS), and these often must be derived from equations that depend on the receiving stream hardness (as CaCO3). The WQCD uses the mean hazdness of the receiving stream for these calculations, up to the 400 mg/1 hazdness cap discussed in Regulation No. 31. 31.16 Table III, footnote 3. The mean hardness of Arequa Gulch is 698 mgJl at AG1.5 as 650 mg/1 at AG2.0. The maximum hazdness of400 mgA was used for calculating the standazds for Arequa Gulch. The mean hardness ni Cripple Creek was used to calculate the hazdness-based standazds for Cripple Creek (Segment 21). The mean hazdness was computed to be 185 mgfl, based on sampling data from CC&V Station 0003 (Cripple Creek approximately 0.1 miles downstream of the mouth ofArequa Gulch) located on Cripple Creek (see Figure 3 of the Permit). This hazdness value and the formulas contained in the TVS were used to calculate the in-stream water quality standazds for metals. Cripple Creek does not have standards in place for aluminum, but Arequa Gulch does. In the case of aluminum, the applicable acute and chronic standards, AI (ac/ch)=11,000 ug/1, on Arequa Gulch will be used to calculate the assimilative capacities in Arequa Gulch'. Assimilative capacity for alunnnumwas not calculated for Cripple Creek. Appendix A Page 4 of 13