PERMFILE126208

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 6/24/2004
• Section_Exhibit Name: Exhibit 07 NPDES Permit
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF P[IBL[C HEALTH AND ENV/RONMENT, Water Qualiry Control Division
Rationrt[e-Pnge 4, Permit No. CO-0038776
2. Discussion ofEfRuent Limitations
a. BOD TSS total residual chlorine oil and rease and K' The ReQttlotions for Effluent Limitations (Regulation No. 62)
in~e a went imitations [ at app y to a isc arges o wastewater to State waters. ese~ons are applicable to
the discharge from the West Elk Mine WWTF.
The BOD and TSS concentraSons bom the Re ulations or E went Limitations are the most stringent effluent limits and
are therefore applied at internal UOuutfa[I 00 as per proce use. to p~ercent removal percentages for BODS and
TSS based on the ReQZZlations for Effluent Limitations a o applyy at internal Outfall 007. These limits are the same as the
previous permit limits an t u5 are impose a ecttve immediately.
Discharges from internal Outfall 007 enters pond MB-2R from which Outfall 004 discharges. Since additional treatment
for total reszdual chlorine is afforded in pond MB-1R, the total residual chlorine limitation based on the Re lotions or
Effluent Limitations. which is more stringent than the limit based on water ualiry, shall not be imposed at interns t a
ur instea at Outfdll 004. Although no total residual chlorine e~luent data are available at Outfall 004, the
discharge should be able to meet this limit and therefore it is imposed effectzve immediately.
For the same reasons discussed above, pH and oil & ease limitations are not being imposed at Outfat1007 and instead
apply at the point ofdischarge to state waters, Outfal[ 004. These limitations are the same as in the previous permit and
are effectve zmme zately.
b. Fecal Coli orm: The State's Procedure or Selection o Fecal Coli orm Limitations Permit Conditions establishes limits for
eca co z orm: 6,000 organisms per m - ay geometric mean an organisms per ml (7-dayy ggeometrzc
mean). ese limits are more strtngent than the limit based on water quality. Therefore, the limits at Outfa11007 will be
set at the levels s ecified in the Procedure for Selection of Fecal Caliform Limitations Permit Conditions. Because no
other sources of fecal coliform are expected zn Pond MB-211 and ecal coliform treatment is not conducted in Pond MB-2R,
no fecal coliform limits or monitoring will be required at Ou~ll 004 and instead fecal coliform limits are imposed a1
Outfa11007.
The fecal coliform limitations determined for Outfall 007 are equal to the previous permit limtu and thus are imposed as
permzt limits effective immediately.
c. off - This parameter is applicable to all 12 Outfalls from this facilittyy that discharge directly to State waters and is limited
by water qualiy standards as the water quality standards o 6.5-9.0 s. u. rdnge are more stringent than those specified
under the Rent/ations {or Effluent Limitations. These limits are the same as those previously zmposed and are effective
immediate y.
d. Aoolicable Federal Effluent Guidelines and Standards: The federal guidelines that apply to this type of aciliry are found
un ear 6CF1~434, hi7edZoa tnzn¢ oznt our~aferorv. The limitations that apply, effective imme~dtely, are.•
-- Federal Standards !40 CFR
pH, s. u. (Minimum -maximum) I 6.0 - 9.0
~otal Suspended Solids, mg/1 * 35 70
BAT** I 3.5 7.0
NSPS* *' 3.0 6.0
~ Senlea6le Solids. ml/l " NA 0.5
der 5/4/84
Alternate Limitation garden o Proo Re uirements: In conformance with 40 CFR 434.63, the ermittee has the burden of
proo w zen see dng re i om rota suspen a so ids (TSS), total iron, and/or settleable solids (PSS) limitations. Dtscharges
from Out(alls Dll, 012, 13, and 017 are not eligzble for this relief. Outfalls 004 and 016 may be eligible for relief from
TSS, total iron, and SS; however, the majority of the Zoadine from an discharge has to consist ofstorm runofffor the relief
to be available. The permittee will need to show thal exce ence of the applicable limitations was caused b pprecipitation
and not mine water, through a compparison o(the loadin from each source. The remaining permitted Ou~[!s (005, 008,
009, 014, 015 and 018) are eligible for relief from TS~ total iron and SS at all times sznce only surface runoff water
discharges are authorized from these outfalls.
Last Revised: 4/192004