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PART I <br />Page 10 <br />Permit No. CO-0038776 <br />B. h[ONITORLYG REQUIItE~~NTS <br />3. ASUte WET TestinE - Outfalls Ol 1. Ol3 and 017 !continued) <br />The permit[ee shall conduct an acute a8-hour WET test using Ceriodaphnia sp., and an acute 96-hour WET test using <br />fathead minnows. Acute tests will be replacement static tests of a single effluent grab sample. The permi«ee shall <br />conduct each acute WET test in general accordance with methods described N Methods for bleasurine the Acute <br />Tazicity of Effluents and Receiving Waters to Freshwater and Marine Oro_utisms, EPA/600/J-90/027 or the most <br />current edition, except u modified by the most cunen[ Division guidance document entitled Guidelines for Conductin¢ <br />Whole Effluent Toxicity Tests. <br />(b) Failure of Test and Division Notification <br />An acute WET test is Failed whenever the LCSO, which represents an estimate of the effluent concen[ra[ion which is <br />lethal to 50 0 of [he [es[ organisms in the time period prescribed by the test, is found [o be less than or equal [0 100 a <br />effluent. The permittee mast provide written notification of the failure of a WET test [o the Division, along widt a <br />statement as to whether the Preliminary Toziciry Incident ('PTI")/Toziciry [den[ification Evaluation ('TIE') <br />investigation or accelerated testing is being performed (see nett section). Notification must be received by the <br />Division within 14 calendar days of the demonstration of acute WET in the routine required test. <br />"Demonstration" for [he purposes of Pars I.B.3.(b),(c),(d) and (f) means no later than [he lut day of the laboratory <br />test. <br />(c) Automatic Compliance Schedule Upon Failure of Test <br />If a routine acute WET test is failed, the following automatic compliance schedule shall apply. As pan of [his the <br />permittee shall either: <br />(i) proceed to conduct the PTI/T[E investigation as described in Pan I.8.3.(d), or <br />(ii) conduct accelerated testing using the single species found to be more sensitive. <br />If accelerated testing is being performed, the permittee shall provide written notification of the results within la <br />calendar days of completion of the "Pattern of Toxicity"/"No Toxicity" demonstration. Testing will be a[ leas[ <br />once every two weeks for up to five [escs until 1) two consecutive tests fail or three of five tests fail, in which case a <br />pattern of toziciry has been demonstrated or, 2) two consecutive [escs pus or three of five tests pass, in which case no <br />pattern of toziciry has been found. if no pattern of toziciry is found the toziciry episode is considered [o be ended and <br />routine testing is to resume. If a pattern of toziciry is found, aPTI/TIE investigation is to be performed. If a pattern <br />of tonicity is not demaastra[ed but a significant level of erratic toziciry is found, the Division may require an increased <br />frequency of routine monitoring or some other modified approach. <br />(d) i/ I <br />The results of the PTi/TiE investigation are to he received by the Division within l20 days of the demonstration <br />of acute WET in the routine test. as defined above. or if accelerated testing is performed. the date the pattern of <br />toxicity is demonstrated. A status report is to he provided to [he Division at the 30. h0 and 90 day points of the <br />PTI/TiE investigation. The Division may extend the time frame for investigation where reasonable justification <br />exists. A request for an extension must be made in writing and received prior to the 120 day deadline. Such request <br />must include a justification and supporting data for such an extension <br />The permittee may use the time for investigation to conduct a PTI or move direcdy into the TIE. A PTI consists of a <br />brief search for possible sources of WET, which might reveal causes of such toziciry and appropriate corrective <br />actiops more simply and cost effectively than a formal TIE. [f the PTI allows resolution of [he WET incident, the TIE <br />need no[ necessarily be conducted. lf, however, WET is not identified or resolved during the PTi, the TIE must be <br />conducted within the allowed l.0 day time frame. <br />• Amendment No. 2 Issued 9 997 Effective APR OL. 1997 <br />Amendment No. a Issued ~$ffecti~pOp + v_, <br />r1i 1-7 TTJ(- <br />