HYDRO24187 - Laserfiche WebLink

Home Browse Search

COLORADO DEPARTMENT OF HEAt.TH, Water Quality Control Division Rationale -Page 11, Perntit No. CO-0043648 Table III - 6, cortl'd Quality of Receiving Water Station AG-1.5, Below the Valley Leach Facility, May, 1995, tltru February, 1996 No. ~ 85th Parameter Samples tYlin. Max. Avg. Std.Dev. Median Pcn[f Alttminunt, Dissolved, mgfl 11 0.80 22 8.073 6.065 6.8 17.0 Arsenic, PD, n:g/1 ]I 0.00 0.0 0.0 0.0 0.0 0.0 Cadmium, Dissolved, mg/1 /1 0.00 0.0/7 0.0/0 0.004 0.0/0 0.012 Chromium. Total, mg/l 1 ] 0.00 0.01 0.001 0.003 0. D 0.0 Copper, Dissolved, mg/l /1 0.00 0.074 0.02! 0.023 0.010 0.042 Iron, TR, mg/l 11 0.0 4.6 1.2 1.4 0.58 2.4 Lead, Dissolved, tng/l 1/ 0.00 0.00 0.00 0.0 0.0 0.0 Manganese, TR, mg/l 11 0.0 7.8 1.9 2.5 0.0 3.7 Manganese, D, mg/l 1! 0.12 12 6.5 4.0 3.9 11.0 Mercury, PD, mg/1 l ] 0.00 0.0 0.0 0.0 0.0 0.0 Nickel, Dissolved, mg/1 II 0.00 0.08 0.038 0.023 0.03 0.06 Selenium, Dissolved, mg/1 11 0.00 0.008 0.001 0.002 0.0 0.0 Silver, Dissolved, mg/l 11 0.00 0.006 0.00/ 0.002 0.0 0.0 Zinc, Dissolved, rng/l 11 0.05 1.3 0.644 0.310 0.69 0.80 PD -Potentially Dissolved TR -Total Recoverable 2. Quantity. Acute and Chronic Low Flowr -The flows which are ordinarily used to cn[culate acute and chronic effluent limitations are the one day in three year low flow (I E3) and the 30 day in three year low flow (30E3) respectively. Those flows have been determined for Arequa Gulch and Squaw Gulch by the Water Quality Control Division, and are as follows (all flows in cubic feet per second): Table III - 5 -- Acute and Chronic Low Flows Acute' Chronic Annual 0.0 0.0 /t should be noted that the flow pasterns of Arequa Gulclt may have been altered by the construction of the Valley Leach Facility, as weft as the Arequa Gulch Waste Rock Storage Area, and the flow may no longer 6e intermittent. Also, it is possible that flows in Squaw Gulch will be affected by the Ironclad Waste Rock Storage Area. However, it appears that the flow of Squaw Gulch will continue to be ephemeral. In either case, the limits included in tIris permit have been developed somewhat independently of low flow considerations and minor shifts in Jlow patterns may not be a significant concern. 3. /ntpacts on Downstream Water Supplies or Other Receiving Waters Provided that fire terms and conditions of this permit are complied with, and that the permittee complies with the terms and conditions of it's approval from rite State Division of Minerals attd Geology, it is expected that there will be no adverse impact to downstream water supplies or outer receiving waters.