2009-08-10_GENERAL DOCUMENTS - M1977300 (2)

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Environmental Protection Plan, Schwartzwalder Mine 11-5 Table 11-3. Water Quality Standards for Ralston Creek Stream Segment 17b STREAM SEGMENT DESCRIPTION REGION: 3 BASIN: Clear Creek STREAM SEGMENT: 17b. Mainstem of Ralston Creek from the source to the inlet of Arvada Reservoir, including Ralston Reservoir, and Upper Long Lake. DESIGNATION: UP QUALIFIERS: Water + Fish, Organics CLASSIFICATIONS: Aq Life Cold 2, Recreation la, Water Supply, Agriculture NUMERIC STANDARDS Basis of calculated standards: PH = 7.06 s.u., low-flow average at SW-BPL, post sump shut-off T = 1.25 °C, low-flow average at SW-BPL, post sump shut-off Hardness = 163 mg/L, low-flow average at SW-BPL, post sump shut-off Physical and Biological acute chronic D.O.* 6.0 mg/L D.O. (sp)* 7.0 mg/L PH* 6.5-9.0 S.U. F. Coli* 200/100mL count E. Coli* 126/100mL count Inorganic Ammonia* 22.8 5.77 (elsp) mg/L as N total Chlorine* 0.019 0.011 mg/L total residual Cyanide* 0.005 mg/L free Sulfur* 0.002 mg/L Boron* 0.75 mg/L Nitrite* 0.05 mg/L Nitrate* 10 mg/L Chloride* 250 mg/L Sulfate (ws)* 250 mg/L Metals Aluminum 750 87 ug/L total recoverable Arsenic, * 50 --- ug/L total recoverable Cadmium(* 2.60111(tr) 0.61(2) ug/L dissolved Chromium III* 50 --- ug/L total recoverable Chromium VI* 16 11 ug/L dissolved Copper* 213 13.6 ug/L dissolved . Iron, dissolved (ws)* 300 ug/L dissolved Iron, total recoverable* --- 1000 ug/L total recoverable Lead* 109.5131 4.27141 ug/L dissolved Manganese* 3513 1941 ug/L dissolved Manganese (ws)* --- 50 ug/L dissolved Mercury, Total* --- 0 ug/L total Nickel* 707.9 78.6 ug/L dissolved Selenium* 0.0184 0.0046 ug/L dissolved Silver* 4.70151 0.74 ug/L dissolved Thallium --- 15.00 ug/L dissolved Uranium 4116 2571 ug/L dissolved Uranium, at the intake 40 pCi/L dissolved Uranium, at the intake 0.059 mg/L dissolved Zinc* 217.4161 188.511 ug/L dissolved Radionuclides Americium 241 0.15 pCi/L total Cesium 134 80 pCi/L dissolved Plutonium 239 and 240 0.15 pCi/L total Radium 226 and 228 5 pCi/L total Strontium 90 8 pCi/L total Thorium 230 and 232 60 pCi/L total Tritium 20,000 pCi/L dissolved NOTES: Standards from Colorado Administrative Code 5CCR 1002-31 and 5CCR 1002-38 (effective July 1, 2007) Values in this table calculated using a water effect ratio (WER) of 1.0 unless otherwise noted *Required by site-specific standards (sp) - spawning standard (elsp) - early life stages present (ws) - water supply standard (tr) - trout standard (1) Cadmium KA = 1.136672 - (In(hardness) x 0.041838) = 0.924 (2) Cadmium KC = 1.101672 - (ln(hardness) x 0.041839) = 0.889 (3) Lead KA = 1.46203 - (In(hardness) x 0.145712) = 0.720 (4) Lead KC = 1.46203 - (In(hardness) x 0.145712) = 0.720 (5) Silver KA = 0.5 (6) Zinc KA = 0.978 (7) Zinc = 0.986 Equation for Ammonia acute standard is based on "salmonids present:" = 0.275/(1+107.204 .px) + 39.0/(1+I0on-7.101) Equation for Ammonia chronic standard is based on elsp = 2.85 x [0.0577/(1+l07.6"-Pa) + 39.0/(1+]0pH-7_6se)] when T < 22. 15 Note: Colorado began adopting new designations for recreational water quality classifications in 2005. Under the new nomenclature, Category E is existing primary contact recreation (formerly Category la). 4109C.090807 Whetstone Associates