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' PART I Page No. 6 Permit No.: CO-0032115 Should a precipitation event or snowmelt occur, the permittee shall submit adequate proof in order for an exemption to be claimed. Weather station data maybe appropriate in making this demonstration. Said proof shall be submitted as an attachment to the Discharge Monitoring Report (DMR) for the appropriate period. The Division shall detetrnine the adequacy of proof. As part of this determination, the Division shall evaluate whether the permittee could have controlled the dischazge in such a mammer that primary limitations could have been met. All manual dewatering of ponds that aze equipped with automatic dewatering systems must meet TSS and total iron limitations. If a pond has only manual dewatering capability,; relief is available only to the extent required to regain necessary stability and capacity. 3. Post=Mining Areas In conformance with 40 CFR 434.50, commencing at the time active mining has ceased and al] surface areas served by a sedimentation pond have been returned to the requred contour and revegetation has commenced, applicable dischazges may be eligible for post-mining limitations. In most cases, these post-mining limitations shall remain in effect until bond release. The permittee shall notify the Division at the appropriate time so that consideration of permit modifications can be made. Prior to notification and subsequent permit modification, active mining ]imitations will apply regazdless of actual mine status. 4. Compliance Schedules a. Twelve Time Analysis - Outfalls 011, 017, 019, 020, 021, 023: The permittee shall complete a twelve time analysis as described in Part I.B.3. Twelve consecutive monthly grab samples shall be collected at Outfalls 011, 017, 019, 020, 021, 023 and analyzed with all results being submitted at the end of the sampling period. A summary report in the form of a letter shall be submitted to the Permits Unit by Seutember 30, 2005. The pennittee may attach the laboratory results if they choose. This report shall include all sample results collected over the twelve month period. If sampling is incomplete, this shall be noted in the report. If sampling has not yet been completed by this date, this twelve time analysis requirement shall continue until twelve samples have been collected and analyzed and the results submitted to the Pemtits Unit. 5. Acute WET Testing - Outfalls 011, 017, 019, 020, 021, 023 a. Testin¢ and Reporting Requirements Tests shall be done at the frequency listed in Part I.B.1. and is only required if mine water is being dischazged. 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 April 28.) The results shall be submitted on the Acute Toxicity Test report form, available from the Division. Copies of these reports aze to be submitted to the Division along with the DMR. The pernilttee shall conduct an acute 48-hour WET test using Ceriodaphnia sp., and an acute 96-hour WET test using fathead minnows, as specified in Part LB.1. Acute tests will be replacement static tests of a single effluent grab sample. The permittee shall conduct each acute WET test in general accordance with methods described in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, EPA/600/4- 90/027 or the most curent edition, except as modified by the most curent Division guidance document entitled Guidelines for Conducting Whole Effluent Toxicity Tests. b. Failure of Test and Division Notification An acute WET test is failed whenever the LCso, 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 pemvttee 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 (see next section). 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 proposes of subparts b., c., d. and f. means no later than the last day of the laboratory test. c. Automatic Compliance Schedule Upon Failure of Test If a routine acute WET testis failed, the following automatic compliance schedule shall apply. As part of this the pemvttee shall either: i. proceed to conduct the PTUTIE investigation as described in subpart d., or ii. conduct accelerated testing using the single species found to be more sensitive.