2009-03-06_PERMIT FILE - C1981012A ‎(6)‎

• Permit No: C1981012A
• IBM Index Class Name: Permit File
• Doc Date: 3/6/2009
• Section_Exhibit Name: Exhibit 22 NPDES Permit
• Media Type: D
• Archive: Yes

New Elk Mine Water Quality Assessment
r7
U
CO-0000906
Table A-9
DBACs for Potential Pollutan ts of Concern for Outfall OOIA
SCTs and A Q 144) 4S)
02 QI "(Cfs) . " ADB

Pollutant SCT

4
3
.
0.45

4.75
As, TR (µg/1) 15 0 .
4.3 0.45 4.75
Cd, Dis (µg/1) 0.20 0 3.0 0.45 3.45
Cr, Tot (µg/1) 7.5
1
8
4.3
0.45
4.75
Cu, Dis (µg/1) 4'9 .
0 4.3 0.45 4.75
Pb, Dis (µg/1) 0.56
27 4.3 0.45 4.75
--
Mn, Dis (4g/1) 316
Hg, Tot (µg/1)
11
0 4 3 0.45 4.75
Ni, Dis (4g/1) 2
2 4.3 0.45 4.75
Se, Dis (µg/1) 1.7 .
0 4.3 0.45 4.75
Ag, Dis (µg/1) 0.021

3
4
0.45
4.75
Zn, Dis (µg/1) 39
14
0 0
0.028 .
4
.3 0.45 4.75
B, Tot (mg/1) .
245 137 3.0 0.45 3.45
Al, TR (µg/1)
0
3.0
0.45
3.45
As, Dis (4g/1) 51
158
2.11
57.5
34.5
5.91
3,078
0
116
0.222
412
1.21
965
391
* Based on these calculations, the ambient water quality exceeds the SCT for dissolved selenium. Where an assimilative
capacity is calculated to be less than the standard, the Division standard procedure is to allocate the water quality
• standard, which in this case is the SCT, to prevent degradation of the receiving stream.
In lieu of being subject to the ADBACs, facilities Iiave the option of selecting non-impact limits
(NILs), which are concentration limits based on dicir existing permitted load and the proposed
design flow. By agreeing to meet the NILs, new or increased impacts will not occur and thus
ADBACs will not be required to be considered in CDPS permits. For those pollutants for which
permit limits have not yet been established, an implicit load allocation is determined and an implicit
permit limit is established. For total recoverable arsenic, dissolved cadmium, total recoverable
trivalent chromium, dissolved copper, dissolved lead, dissolved manganese, total mercury, dissolved
nickel, dissolved selenium, dissolved silver, dissolved zinc, total boron, dissolved arsenic and total
recoverable aluminum, implicit limits were determined based on the Division's standard approach
that specifies that implicit limits be developed based on the maximum concentration. However,
because the facility was not discharging from Outfall 001 during the antidegradation period, the
maximum concentration for all pollutants is equal to zero.
For all pollutants evaluated, a summary of the existing permit limits (including implicit limits), the
existing permitted loads, the new WQBELs, the new WQBEL loads, ADBACs and NILs are
contained in Table A-10.
•
Appendix A (WQA version 5-4(FABL)) Page 27 of 29 Last Revised August 26, 2008