PERMFILE107884

• Permit No: C1980001
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: AIR AND WATER PERMITS
• Section_Exhibit Name: 3.7 APPENDIX 3.7-D
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 9. Permit No. CO-0032638
APPENDIX A
Water quality standard (WQS) based effluent limitations are calculated using
the following mass balance formula:
EL WQS (Q7-10 + QEFF) - (Q7-10 X CAMB)
QEFF
Where:
EL = Calculated effluent Limitations (mg/1)
WQS = Applicable water quality standard Cmg/1)
Q7-10 = Receiving water 7-day, 10-year low flow (6.0 cfs)
QEFF Maximum effluent flow (6.43 cfs) (combined)
Cog =Ambient instream concentration (mg/1)*
Following are some specific calculations:
iron
EL 1.0 (6.0 + 6.43) = 1.9 mg/1
6.43
Cadmium
EL = 0.001 (6.0 + 6.43) = 0.002 mg/1
6.43
Silver
EL = 0.0001 (6.0 + 6.43) = 0,0002 mg/1
6.43
Mercury
EL = 0.00005 (6.0 + 6.43) = 0.0001 mg/1
6.43
T.R. Manganese (Outfall 006 Only)
EL = 1.0 (6.0 + 3.53) 2,70 mg/1
3.53
~~ * No ambient data is available