HYDRO25324

• Permit No: M1988112
• IBM Index Class Name: Hydrology
• Doc Date: 12/22/2000
• Doc Name: MEMO NOTICE OF ISSUANCE OF THE PERMIT FOR BATTLE MTN GOLD CO-0045675
• From: CDPHE
• To: ATTENDEES AT THE PUBLIC MEETING ON THE BATTLE MTN PERMIT CO-0045675
• Media Type: D
• Archive: No

Page 2i
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale -Page 20 Permit No. CO-0045675
percent o/the available increment between low flow pollutant concentrations end the relevant
standards, (or critical constituents; or
(iv) The activity will result in only temporary orshort-term changes in water quality.
VI.B.4. Discussion of Effluent Limitations (Cont.)
(d) Antidegredation Review: (Cont.)
For the BMRI anfrdegredation review, conditions (i) and (iv) as described above are not applicable, since
the dilution ratio is less than 100 to 1, and this is not ashort-term or temporary discharge. The
antidegredation-based water quality standards and limitations for this permd are based upon
considerations of (ii) and (iii) which are described previously.
Thus, the antidegredation-based limitations are calculated by either: 1) the new loading is less than 15
percent of the available increment between low-slow pollutant concentrations and the relevant standards,
or 2) the new loading (or each parameter is less than 10 percent of the baseline load. Inmost cases, the
15 % incremental increase is used as the basis for the antidegredation-based limitation. Table VI-3
following shows the antidegradation-based and wafer quality standard-based calculations.
Table VI-3 -- Summary of Mass Balance Calculations- Outfall OOfb (250 gpm discharge /low) _
Antidegradalion-Based '
1
~ Segment 28 Antidegradafion- 8/or WQS-Eased #
Upstream
Ambient Mean Wafer Duality Std Based WOS F.(fluent Concentration
Perimeter Concentration ~ Acute/Chmnic Chronic (orACUfe) Acute/Ch,vnic
(mg4) ~ (M1) rJ '~ (M3) >}/ (M31 (M2)
Ammonia, Total as N 0.025 g/ 0.414 0.232 0.90 '
Boron, Total 0.050 g/ 0.750 0.155 0.494'
Chloride, Total 3.0 250 42.4 169 '
Total Residual Chlorine 0 ~ 0.01910.011 0.011 0.063#/0.011' g/
Cyanide, Free 0.0050 g/ 0.005 (acute) 0.005 (/ 0.005'
Fecal Coli(orm Bacteria, NoJ100 ml 0 pr 2000 2000 g/ 2000 ' N
Fluoride, Total 0.50 (4.0=MCL) (1.165) 2.7 '
Nitrate, Total as N 0.065 f0 (acute) 2.10 6.9 '
Nitrite, Total as N 0 d/ 0.050 0.050 !Y 0.050 ' g/
Sulfate, Total 9.1 250 74 283 '
Sulfide as H=S 0.000025 g/ 0.002 0.00073 0.0030'
Arsenic, Total 0.00050 g/ 0. 050 (acute) 0.0084 0.027 '
Cadmium, Potentially Dissolved 0.000050 g/ 0.0059710.00080 0.00016 0.020#/0.00053'
Chromium, Trivalent, Tot. Rec. 0.00050 g/ 0.050 (acute) 0.0083 0.026 '
Chromium, Hexavalent, Pot. Dis. 0.00050 g/ 0.0160.011 0.0024 0.052# / 0.0086 '
Copper, Potentially Dissolved 0.00050 g/ 0.0120.0081 0.0016 0.038#/0.0053'
Iron, Dissolved 0.0595 0.300 0.300 f/ 0.300 ' //
Iron, Total Recoverable 0.154 1.0 1.0 (/ 1.0 (/'
Lead, Potentially Dissolved 0.00050 g/ 0.04710.0021 0.00074 0.15#/(1.0015'
Manganese, Dissolved 0.0050 fV 0.050 0.050 (/ 0.050' V
Manganese, Total Recoverable 0.0050 >3/ 1.0 0.376 1.6 '