2009-01-12_PERMIT FILE - C1996083 (2)

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PART I Page No. 7 Permit No.: CO-0044776 6. Chronic WET Testine -- Outfalls 006 and 010 a. Testing and Reportine Requirements Tests shall be done at the frequency listed in Part I.B.1. Test results shall be reported on the Discharge Monitoring Report (DMR) submitted for the reporting period during which the sample was taken. (i.e., WET testing results for the first calendar quarter ending March 31 shall be reported with the DMR due Apri128.) The results shall be submitted on the Chronic Toxicity Test report form, available from the Division. Copies of these reports are to be submitted to both the Division and EPA along with the DMR. The permittee shall conduct each chronic WET test in general accordance with methods described Short Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving_Waters to Freshwater Organisms, EPA/600/4-89!001 or the most current edition, except as modified by the most current Division guidance document entitled Guidelines for Conducting Whole Effluent Toxicity Tests. The permittee shall conduct such tests using Ceriodaphnia dubia and fathead minnows. b. Failure of Test and Division Notification Beginning on the effective date of this permit, a chronic WET test is failed whenever there is a statistically significant difference in lethality between the control and any effluent concentration less than or equal to the instream waste concentration("IWC"). The IWC for outfalls 006 and 010 has been determined to be 100%. The permittee must provide written notification of the failure of a WET test to the Division, along with a statement as to whether a Preliminary Toxicity Investigation ("PTl")/Toxicity Identification Evaluation ("TIE") or accelerated testing is being performed. Notification must be received by the Division within 21 calendar days of the demonstration of chronic WET in the routine required test. "Demonstration" for the purposes of subparts b., c., d., e. and g. means no later than the last day of the laboratory test. c. Automatic Compliance Schedule Upon Failure of Test If a routine chronic WET test is failed, the following automatic compliance schedule shall apply. As part of this the permittee shall either: i. proceed to conduct the PTI/TIE investigation as described in subpart d., or ii. conduct accelerated testing using the single species found to be more sensitive. If accelerated testing is being performed, the permittee shall provide written notification of the results within 14 calendar days of completion of the "Pattern of Toxicity"/"No Toxicity" demonstration. Testing will be at least 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 pattern of toxicity has been demonstrated or 2} two consecutive tests pass or three of five tests pass, in which case no pattern of toxicity has been found. If no pattern of toxicity is found the toxicity episode is considered to be ended and routine testing is to resume. If a pattern of toxicity is found, aPTI/TIE investigation is to be performed. If a pattern of toxicity is not demonstrated but a significant level of erratic toxicity is found, the Division may require an increased frequency of routine monitoring or some other modified approach. d. PTI/TIE The results of the PTI/TIE investigation are to be received bv_the Division within 120 days of the demonstration of chronic WET in the routine test as defined above or if accelerated testing is performed, the date the pattern of toxicity is demonstrated. A status report is to be provided to the Division at the 30, 60 and 90 day points of the PTI/TIE investigation. The Division may extend the time frame for investigation where reasonable justification exists. A request for an extension must be made in writing and received prior to the 120 day deadline. Such request must include a justification and supporting data for such an extension. The pennittee may use the time for investigation to conduct a PTI or move directly into the TIE. A PTI consists of a brief search for possible sources of WET, which might reveal causes of such toxicity and appropriate corrective actions more simply and cost effectively than a fonnal TIE. If the PTI allows resolution of the WET incident, the TIE need not necessarily be conducted. If, however, WET is not identified or resolved during the PTi, the TIE must be conducted within the allowed 120 day time frame.