2008-09-15_PERMIT FILE - C1992081

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PART II Page No. 11 Permit No. COG-850000 Guidelines for Conducting Whole Effluent Toxicity Tests. The pennittee shall conduct an acute 48-hour WET test using Ceriodaphnia sp., and an acute 96-hour WET test using fathead minnows. Acute tests will be replacement static tests of a single effluent grab sample. 2. Failure of Test and Division Notification An acute WET test is failed whenever the LC50i which represents an estimate of the effluent concentration which is 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% effluent. The permittee must provide written notification of the failure of a WET test to the Division, along with a statement as to whether the Preliminary Toxicity Incident (PTI)/Toxicity Identification Evaluation (TIE) investigation or accelerated testing is being performed. Notification must be received by the Division within 14 calendar days of the demonstration of acute WET in the routine required test. Demonstration for the purposes of Parts LA.3.b., c., d. and (f) means no later than the last day of the laboratory test. b. Chronic WET Testing (See also Part I.B.7.c for WET requirements applicable to both chronic and acute WET testing) 1. Testing and Reporting Requirements Tests shall be done at the frequency listed in Part I.B.1. Test results shall be reported along with 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 the Division along with the DMR. The pennittee shall conduct each chronic WET test in general accordance with methods described in Short Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Or anisms 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 Toxici Tests. The permittee shall conduct such tests using Ceriodaphnia dubia and fathead minnows. 2. Failure of Test and Division Notification A chronic WET test is failed whenever 1) 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) and, 2) the IC25i which represents an estimate of the effluent concentration at which 25% of the test organisms demonstrate inhibition as reflected by lethality, is at any effluent concentration less than or equal to the 1WC. The IWC for this permit has been determined to be 21.5% at Outfal1001A and 100% at Outfall 002A. 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 (PTI)/Toxicity Identification Evaluation (TIE) or accelerated testing is being performed (see Part I.A.3.d.). 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 Parts LA.3.b., c., d. and f. means no later than the last day of the laboratory test. c. Other WET Testing Requirements Applicable to both Chronic and Acute WET Testing 1. Automatic Compliance Schedule Upon Failure of Test If a routine chronic WET test is failed, regardless of whether the limit is in effect, the following automatic compliance schedule shall apply. As part of this, the permittee shall either: i. Proceed to conduct the PTUTIE investigation as described in Part I.A.3.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, a PTI/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.