HYDRO21737

• Permit No: M1977306
• IBM Index Class Name: Hydrology
• Doc Date: 6/23/2005
• Doc Name: water sampling reports
• From: cotter
• To: dmg
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Conu~ol Division
Rationale -Page 5, Permit No. CO-0036251
VI. TERMS AND CONDITIONS OF PERMIT
A. Determination of Effluent Limitations(Continued)
2. DiscussionofE/fluentLimitations
The bases for the effluent limitations for uranitnn, radium species, COD, TSS, and zinc are unchanged from the previous
permit and all of the limitations from the previous per•rnit have been included in this permit. Please see the previous
rationale jor a detailed discussion. None of the limits in this permit are derived from the water quality standard-based
muss balance egtrntion calculations. Effluent limitations for radium 226 and 228 are taken front Section 31.11 of The
Basic Standards and Methodolozies o{Sur{nce Water. which establishes basic standards applicable to all waters of the
state.
a. BODt TSS. Total Residtenl Chlorine, pH. and Oil artd Grease -The Renrlatians {or E{Iltrent Limitations (Regulation
No. 62) include effluent limitations that apply to all discharges of wastewater to State waters, with the exception of
stornnvnter and agriculunnl return flows. These regulations are npplicnb[e to the disdtnrges from the Cotter
Corporation JD-7 and JD-9 Mines.
From the parameters listed above, only those for Oil and Grease and pH m'e applicable pollutants of concern for
discharges to waters of the State from the Cotter Corporation facility. Consequently, the limitations in this permit
jor Oil and Grease and pH are based at the Re¢trlations (or Effluent Limitatons.
b. Applicable Federal Effluent Guidelines and Standards: The federal guidelines that apply to this type offaciliry m•e
found under 40 CFR PART440, titled "ORE MINING AND DRESSING POINT SOURCE CATEGORY, Subpart C,
Uranium Radium and Vanadium Ores Subcnteeorv ", parts 440.32(a) and 440.33(a). The limitations that apply
represent the degree of reduction available by the application ojthe best practicable control technology currently
available (BPT), and the application of the best available technology cznrently available (BAT), respectively. See
Table VI-2 below for these standards.
Ta61e VI-2 - Federaf Effluent Limitations
TS$ mg/1 20 30
COD, mg/l 100 200
Dissolved Radium 226, pCi/1 3 10
Total Radium 226, pCi/! 10 30
Total Uranium, mg/1 2 4
Total Zinc, mg/l 0.5 /.0
pH, standard units 6.0 - 9.0
Pollutants Limited by Water• Quality Standards - FABL Environmental Regulatory Specialists, lac. has performed
an assessment ofpotential water quality standards-based assimilative capacities fa~ the Water Quality Control
Division and made a preliminary deterntination of the assimilative capacity of the receiving stream for the
pollutants of concern. This assessment can be found in AppendixA of the rationale. The Permits Unit evaluated the
assimilative capacities and has made n determination as to whether there is n reasonable potential for discharges
from this facility to cause or contribute to nn exceedance of an in-stream standard. /fit is found that there is a
reasonable potential jor the discharge to contribute to an erceedance, effluent limits are included in the permit.
Zinc: The limitations listed in Appendix A were fozrnd to be less sh~ivtgent than the Fedw~al standards in Table VI-2.
Therefore, the most stringent value applies.