2012-06-08_PERMIT FILE - C2009087A (2)

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PART I Page No. 5 Permit No.: C00048275 Total Recoverable Iron, ug/I 1000 NA Report Settleable Solids, mUl Report NA Report Outfall WTA [OutfaIls 002 and 003 combined Effluent Parameter Effluent Limitations Maximum Concentrations 30 -Day Average 7 -Day Averaee Daily Maximum Statistical Difference and WET, chronic * NA NA IC25 > IWC (IWC = 100% effluent) * based on flow weighted composite of these two outfalls, on the day of sample collection 2. AIternate Limitation Burden of Proof Requirements The permittee has the burden of proof when seeking relief fnm total iron and/or settleable solids (SS) limitations, as applicable. All outfalls are eligible for relief from total iron and SS, as applicable; however, the majority of the loading from any discharge has to consist of storm runoff for the relief to be available. The permittee will need to show that exceedanceof the applicable limitations was caused by precipitation (surface runoff water) and not mine water or spoils spring water, through a comparison of the loading from each source. Relief may be granted for each discharge occurrence only when necessary and shall not be granted when the permittee has control over the discharge. The permittee should endeavor to meet the primary limitations whenever possible. For active outfalls: For rainfall, to waive total iron limitations, it is necessary to prove that discharge occurred within 48 hours after measurable precipitation has stopped. In addition, to waive settleable solids limitations, it is necessary to prove that discharge occurred within 48 hours after precipitation greater than the I0•year, 24 -hour event has stopped. For snowmelt, to waive total iron limitations, it is necessary to prove that discharge occurred within 48 hours after pond inflow has stopped. In addition, to waive settleable solids limitations, it is necessary to prove that discharge occurred within 48 hours after pond inflow volume greater than tte 10 -year, 24 -hour event has stopped. b. For post - mining outfalls: For rainfall, to waive settleable solids limitations, it is necessary to prove that discharge occurred within 48 hours after measurable precipitation has stopped. For snowmelt, to waive setleable solids limitations, it is necessary to prove that discharge occurred within 48 hours after pond inflow has stopped. Should a precipitation event or snowmelt occur, the permittee shall submit adequate proof in order for an exemption to be claimed. Weather station data may be 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 determine the adequacy of proof. As part of this determination, the Division shall evaluate whether the permittee could have controlled the discharge in such a manner that primary limitations could have been met. All manual dewatering of ponds that are equipped with automatic dewatering systems must meet 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- Minine Areas In conformance with 40 CFR 434.50, commencing at the time active mining has ceased and all surface areas served by a sedimentation pond have been returned to the required contour and revegetation has commenced, applicable discharges 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 limitations will apply regardless of actual mine status. 4. WET Testing Requirements: