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PARTI
<br />Page No. 15
<br />• Permit No.: CO-0000221
<br />48 hours after pond inflow has stopped. In addition, [o waive settleable solids limitations, it is necessary to prove that
<br />discharge occurred within 48 hours after pond inflow volume greater than the 10-year, 24-hour even[ has stopped.
<br />b. For post-minims outfalls: For rainfall, to waive settleable solids limitations, it is necessary to prove that discharge
<br />occurred within 48 hours after measurable precipitation has stopped. For snowmelt, to waive settleable solids limitations,
<br />it is necessary to prove that discharge occurred within 481tours after pond inflow has stopped.
<br />Should a precipitation event or snowmelt occur, the permittee shall submit adequate proof in order for an exemption to be
<br />claimed. Weather station data may be appropriate in making this demonstration. Said proof shall be submitted as an
<br />attachment to the Discharge Monitoring Report (DMR) for the appropriate period. The Division shall determine the
<br />adequacy of proof. As part of this determination, the Division shalt evaluate whether the permittee could have controlled [he
<br />discharge in such a manner that primary limitations could have been met. All manual dewatering of ponds that are equipped
<br />with automatic dewatering systems must meet TSS and total iron ]imitations. If a pond has only manual dewatering
<br />capability, relief is available only [o the extent required to regain necessary stability and capacity.
<br />4. Post-Minine Areas
<br />In conformance with 40 CFR 434.50, cotnmencing at [he time active mining has ceased and all surface areas served by a
<br />sedimentation pond have been returned to [he required contour and revegetation has commenced, applicable discharges may
<br />be eligible for post-mining ]imitations. Tn most cases, these post-mining limitations shall remain in effect anti] bond release.
<br />The permittee shall notify the Division at the appropriate time so that consideration of permit modifications can be made.
<br />Prior to notification and subsequent permit modification, active mining ]imitations will apply regardless of actual mine scams.
<br />5. Compliance Schedules
<br />No later than 14 calendar days following each date identified in the following schedules of compliance, the permi[[ee shall
<br />submit either a report of progress or, in the case of specific actions being required by identified dates, a written notice of
<br />compliance or noncompliance, any remedial actions taken, and the probability of meeting the next scheduled requirement.
<br />a. Sediment Control Plan - In accordance with 40 CFR Part 434.82, the permittee must submit asite-specific Sediment
<br />Control Plan [o [he permitting authority that is designed to prevent an increase in the average annual sediment yield from
<br />pre-mined, undisturbed conditions, from the following areas: reclamation areas; brushing and grubbing areas; topsoil
<br />stockpiling areas and; regarded areas. For this facility, Outfalls 009A and O15A are required to have a Sediment Control
<br />Plan. The Sediment Control Plan must be approved by the permitting authority and be incorporated into [he permit as an
<br />effluent limitation. The Sediment Control Plan must identify best management practices (BMPs) and also must describe
<br />design specifications, construction specifications, maintenance schedules, criteria for inspection, as well as expected
<br />performance and longevity of the best management practices. Using watershed models, the operator must demonstrate
<br />that implementation of the Sediment Control Plan will result in average annual sediment yields that will not be greater
<br />than the sediment yield levels from pre-mined, undisturbed conditions. The operator must use the same watershed model
<br />that was, or will be, used to acquire the SMCRA permit. The operator must design, implement, and maintain BMPs in
<br />the manner specified in the Sediment Control Plan. _
<br />The permittee is required [o submit the Sediment Control Plan for approval, for Outfalls 009A and O15A, including
<br />documentation of the sediment yield from pre-mining, undisturbed conditions by December 1, 2007.
<br />b. Materials Containment Plan -The pennittee has previously submitted an engineered spill plan. An update to the plan
<br />is required to be filed by February 1, 2007, detailing alt changes [hat have occurred since the original submittal If no
<br />changes have occurred, a letter to this effect is required. For specific requirements, refer to Part LD.1. of the permit.
<br />a. Total Recoverable Iron Final Limitations for Outfalls 002, 003, 005, 006, 010, 011 and 016: The compliance
<br />schedule for total recoverable iron is granted for the permittee [o present information to the Water Quality Control
<br />Commission (WQCC) on [he ambient water quality of the receiving streams, i^ the attempt to obtain asite-specific
<br />standard or temporary modification, based upon the 85ih percentile of the ambient water quality data being higher than the
<br />standard.
<br />i. The pennittee must, by December 31, 2007, submit a progress report surmnarizing the efforts undertaken by the
<br />pernrittee for a site specific limitation For total recoverable iron, in regards to the WQCC hearing for the Upper
<br />Colorado River Basin. -
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