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<br />PART I <br />Page ix <br />Permit No. CO-0032638 <br />B. MONf['ORING REQUIItEMENTS <br />3. Acute WET Testing - Outfalls 004 and 007 <br />a. Testine and Reoortine Requirements <br />Tests shall be done at the frequency listed in Part I.B.1. Test results shall be reported along with the Discharge <br />Monitoring Report (DMR) submitted for the reporting period during which the sample was taken. (i.e., WET testing <br />results for [he fast calendar quarter ending Mazch 31 shall be reported with the DMR due April 28.) The results shall <br />be submitted on the Acute Toxicity Test report form, available from the Division. Copies of these reports are to be <br />submitted to both the Division and EPA along with the DMR. <br />The pennittee shall conduct an acute 48-hour WET test using Daphnia mama, 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 permittce shall <br />conduct each acute WET test in general accordance with methods described in Methods for Measuring the Acute <br />Toxicity of Effluents and Receiving Waters to Freshwater and Mazine Oreanisms, EPA/600/4-90/027 or the most <br />current edition, except as modified by the most current Division guidance document entitled Guidelines for Conducting <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 concentration which is <br />lethal to 50% of the test organisms in the time period prescribed by the test, is found to be less than or equal to 100% <br />effluent. The permittee must provide written notification of the failure of a WET test to the Division, along widt a <br />statement as to whether the Preliminary Toxicity Incident ("PTI")/Toxicity Identification Evaluation ("TIE") <br />investigation or accelerated testing is being performed (see next 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 the purposes of Parts I.B.3.b., c., d. and f. means no later than the last day of the laboratory <br />test. <br />c. Automatic Comoliance Schedule Uoon Failure of Test <br />If a routine acute WET test is failed, regardless of whether the limit is in effect, the fallowing automatic compliance <br />schedule shall apply. As pan of this the petTnittee shall either: <br />(i) proceed to conduct the PTI/T[E investigation as described in Part I.A.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 nolifcation of the results within 14 <br />calendar days of completion of the "Pattern of Toxicity"/"No Toxicity" demonstration. Testing will be at least <br />once every two weeks for up to five tests until 1) two consecutive tests fail or three of five tests fail, in which case a <br />pattern of toxicity has been demonstrated or, 2) two consecutive tests pass or three of five tests pass, in which case no <br />pattern of toxicity has been found. If no pattern of toxicity is found the toxicity episode is considered to be ended and <br />routine testing is to resume. If a pattern of toxicity is found, a PTI/TIE investigation is to be performed. If a pattern <br />of toxicity is not demonstrated but a significant level of erratic toxicity is found, the Division may require an increased <br />frequency of routine monitoring or some other modified approach. <br />See Part I.C. for Definitions. Amendment No. f Issued APRIL 19. 1996 Effective JUNE I. 1996 <br />Amendment No. 3 Issued Effective <br />