HYDRO24291

• Permit No: C1981044
• IBM Index Class Name: Hydrology
• Doc Name: MONITORING REQUIREMENTS
• Permit Index Doc Type: SEDIMENT POND INSPECTIONS
• Media Type: D
• Archive: No

COLORADO DEPARTM11ENT OF HEALTH, Water Qunlin' Contra! Division
Rationale - Pnge l4, Perntit No. CO-0034142
For Outfidls 003, 022, and 024, mctalr e~uent limitnlion.c were cnlcrdnted using n rnaximurn flow oj6?4 cjc (4.03
h1GD) ja' all drree ourfullr, the mera/s .rrnrrdnrdc listed in section ///.A.3. of rhi.c rurionnlc, the nnnun! chronic and
acute lowJlows jar the Willtnm.c Fork Riser listed in .section //1.8.2. and upstream concentrations provided by the
permittee in Table l//-3.
Bn.ced nn n compnri.con ojthe cnlculnted effluent limitations in the Tnhle Vl-6 and the repor'led concentrations in
each ojNre outfnllr stmt was subrniued w the permitlee in the application for renewnl, no water yunlin•-based
ejJluent limimrions, with the exception ojiron and zinc which hove been limited iir the previous permit, there
incorporated in the renewnl permit.
The cnlculnted effluent lirnitntion for zinc tvac bused apon the potentially di.ccolved rnedrod ojonuleris. Since
monitoring dam .c/row that Cypncr Empire hoc Trot lmd difficulty complying with the prevtau.c total recoveruhlezinc
permit fimimtionr, in compliance with federal nnrihnckrliding regulations, there limitations ore remined in the
renewnl permit to insure that there i.c no backsliding ojejJluent yunllry~. /n the even the facility has prob/erns
complying with the toml recoverable zinc lirnimtion.c due to nn inerence in flow ut n later date. the penrriaee may
request the permit he reopened to consider /ess stringent zinc lirnitationc.
d. Anlidegrudation: Since the Williams Fork River is clarcified n.c Use Protected, an nntidegrudu(ipn review is not
reyaired parsuunt to section 3. l.R(lJ(bJ of The Ba.cic Standards and A1etlrodoloeies (n' Sur(nce Water.
e. Salinity Regtdntion.e: In compliance with the "Regu/ntion.c jar hnplememntion o(the Colorado Salinity Standards
Through the CDPS Permit Progrnrn", the permittee shat! monitor far tom! di.c.coived solids on u quarterly busi,c.
Smnples shall be taken n! Nte ejflucnl discharge poin!(rJ. Sulinih~ reyuiremen[c are included ltt Part 1. Sec(/on B.3
ojthe permit.
f. Whole E(J/uen( Toxicity /WET) TectinP For lhi.c facility, clrronic WET reyuir'ementr apply at Outjnlls 003, 022, and
034 (See Parts l.A and l.8 ojthe permit./
lJ Purpose ofWET Tectin~: The Water Quality Control Divi.ciar has es(ublished the u.ce of WET testing us u
method for iderrt fving and controlling toxic discharges from thn.ctewnter'treatrnent facilities. WET testing i.c
being utilized ns n memr.c to ensure dmt there are no discharges ojpollutnnls "in nrnountr, concentrution.c or
combirrurion.r which ore hnrmftd to the henefirinl u.ce.r or taste to humnn.c, animals, plnnLC, or aquatic life" ac
required by Section 3.1. l l (lJ ofthe Bn.cic Smndnrdr and Alethodologier for Sur'Irce Waters.
2) lnetrenm Wn.rte Concentration llWC): Where monitoring or lirnitufion.c for WET are deemed appropriate by
the Division, chronic in.rlremn dilution us repreremed br the chronic IWC is critical in determining whether
acute or chronic condittons shall «pply. For those di.cclrnrge.c where [he chronic 1WC lc greater lhrrn (>) 9.1 %.
chronic conditions apply, tchere the !WC is /et:c than or equal to (~) 9. l acute conditions apply. The chronic
lWC is de(ermined using the following equation:
/WC = [Facility Flow (FFJ/(S[rcnrn Chronic Low Floty (annual) + FFJJ .1" l00%
Because oulfnlLc 003. 022 and 014 discharge to the Willium.c Fork River in the .come vicinity, they ore treated nr
one r/i.cchnrge for this purpose. The flows and corresponding lWCjor the combined discharge ore:
Discharge Point Chronic Low Flow, Facility Design Flow, /WC, (%)
30E3, (cjsJ (cjsJ
003, 022. 024 48 6?4 l1.5