HYDRO31392

• Permit No: C1981019
• IBM Index Class Name: Hydrology
• Doc Date: 6/25/1992
• Doc Name: FINAL PERMIT COLO WASTEWATER DISCHARGE PERMIT SYSTEM COG-850017
• From: CDOH
• To: RICHARD G ATKINSON
• Permit Index Doc Type: NDPES
• Media Type: D
• Archive: No

PART I
Page [;
Permit No. COG-850000
B. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
1. Effluent Limitations (continued)
a) Active Mining Oucfall(s) (continued)
ALTERNATE LIMITATIONS
Any discharge or increase in the volume of a discharge caused by
precipitation within any 24-hour period less than or equal to the
10-year. 24-hour DreciDitacion event (or snowmelt of equivalent
volume) may comply with the following limitations subject to
burden of proof requirements described in Part I.B. 1. d).
Effluent Parameter
Discharge Limitations
Maximum Concentration
Daily Maximum
Flow, MGD Report
pH, standard units (minimum-maximum) 6.5-9.0
Oil and Grease, mg/1 (No visible sheen) 10 e/
Settleable Solids, ml/1 g/ 0.5
Total Dissolved Solids, mg/1 Report
(Colorado River Basin Only)
Total Phosphorus (as P), mg/i Report
(Dillon Reservoir and Upper Bear Creek Drainages Orly)
Any discharge or increase in the volume of a discharge caused Sy
precipitation within any 24-hour period greater than the 10-year.
24-hour Drecioitation event (or.snowmelt of equivalent volume)
may comply with the following limitations subject to burden of
proof requirements describd in Part I.B.l.d).
Flow, MGD - monitoring only per Part I.B.2.a)
pH shall remain between 6.5 and 9.0 s.u.
Oil and grease shall not exceed 10 mg/1.
Total Dissolved Solids, mg/l - monitoring only per Parc I.3.2.a)
(Colorado River Basin Only)
Total Phosphorus (as P), mg/1 - monitoring only per Part I.B.2.a)
(Dillon Reservoir and Upper Bear Creek Drainages Only)
b) Post-Mining Outfall(s)
Post-mining limitations may apply to outfalls serving surface
areas which have been returned to the required contour and on
which revegetation (specifically, seeding or planting) work ;gas
commenced. The permictee may request consideration for change
from active mining limitations to post-mining limitations when
these conditions have been me c. Each facility certification
shall state .rhecher act:~e wining or oast-mining limitations
aDD ly co each au chori_ed oucfall.
gee ?art ?-3-i. for -oocnoces