from Arequa Gulch; and Site CC -04 is just above the confluence of Cripple Creek with
<br />Fourmile Creek. The flows in Cripple Creek generally increase in a downgradient
<br />direction.
<br />Cripple Creek has use classifications for recreation (Class E), agriculture, and as a Class
<br />2 cold water aquatic stream. Standards exist for pH, dissolved oxygen, E. Coli, minor
<br />anions including chlorine, sulfide, and cyanide, nutrients of ammonia and nitrite, as well
<br />as some trace metals (arsenic, boron, cadmium, chromium, copper, iron, lead,
<br />manganese, mercury, nickel, selenium, silver, and zinc). Water quality measurements for
<br />the Cripple Creek stations have been compiled and are presented in Appendix 2, Volume
<br />II of this document. The water quality monitoring in Cripple Creek shows a sodium -
<br />bicarbonate system at the three upstream stations, and a calcium sulfate matrix at the
<br />downstream station (CC -04). The median pH values range from 7.96 to 8.17. Median
<br />sulfate concentrations increase from 79.4 mg/L to 170 mg/L downstream. Median nitrate
<br />levels drop from 12.85 mg/L -N to 7.12 mg/L -N downstream. Sulfate levels may be
<br />attributable to historic mining operations, and nitrate concentrations are due to influences
<br />from the wastewater treatment plant, which can be diluted with increased flows
<br />downstream.
<br />Grassy Valley
<br />Flows in Grassy Valley are ephemeral. CC &V monitors three stations in Grassy Valley.
<br />The oldest station (GV -02) was established in 1996 and the other two stations (GV -01
<br />and GV -03) were established in 1997. The flow data indicate increases in a downstream
<br />direction from GV -01 to GV -02, but often show decreases from GV -02 to GV -03.
<br />Grassy Valley has use classifications for recreation (Class E), water supply, agriculture,
<br />and as a Class 1 cold water aquatic stream. Standards exist for pH, dissolved oxygen, E.
<br />Coli, minor anions including chlorine, sulfide, and cyanide, nutrients of ammonia and
<br />nitrite, as well as some trace metals (arsenic, boron, cadmium, chromium, copper, iron,
<br />lead, manganese, mercury, nickel, selenium, silver, and zinc). Water quality
<br />measurements for the Grassy Valley stations have been compiled and are presented in
<br />Appendix 2, Volume II of this document. The water quality monitoring in Grassy Valley
<br />shows a calcium sulfate system at all stations. The median pH values range from 7.29
<br />upstream at GV -01 to 6.65 at GV -02 and 6.80 at GV -03. Median sulfate concentrations
<br />increase from 41.6 mg /L (GV -01) to 322 mg/L (GV -02) and decrease to 289 mg/L (GV-
<br />03). Median nitrate levels drop from 0.55 mg/L -N at the upstream site (GV -01) to <0.05
<br />mg/L -N at the downstream sites (GV -02 and GV -03). Sulfate levels may be attributable
<br />Cripple Creek & Victor Gold Mining Company
<br />Cresson Project Mine Life Extension 2
<br />4 -12
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