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Mr. Mirbaet Baulay <br />Divirion of Mineratr and Geahgr <br />fnt~ t~, zooz <br />Page z <br />Comment Ib: To demonrtrate complianre with Rule 4.05.9, please provide the following derign information far the <br />temporary impoundmentr T-1 through T-13. <br />• Demanrtration that the impoundment rpillway syrtemr are derigned far the 2Syear, 24 precipilatron event. <br />• Demonstration that the minimum elevation of the top of the rettled embankment u 1.0 foot above the water <br />rurface in the pond with the emergency rpillway flowing at derign depth. <br />• Provide rpillway rapacity information includingpeak dircharge, rpi/lwaygrader and velocity, rpi/lway capacity, <br />and riprap reguirementr. <br />• Provide ride dope information an the ar-built drawingr. <br />For the new ar-built rurveyr rubmitted with the TA-35 application, the Division har the following adequacy <br />concernr. <br />For mock pond T-30, no elevationr were provided on the plan view drawing and the elevation information <br />provided in the Stage Storage Table doer not correlate with the elevation information given in Crorr-Sectionr <br />A A' and B-B' For mock pond T-32, the bottom ofpond elevation given in Crorr Section A A' doer not <br />appear to be correct From the information provided, it appearr that the vertical height of the embankment <br />may exceed five feet, ar mearured from the uprtream tae of the dam to the bottom of the emergency rpillway. <br />Pleare clarify there discrepanaer and provide revived ar-built rurveyr for mock pandr T-30 and T-32. Alro <br />provide the elevation of the uprtream toe of the dam for T-32 or provide adequate information to chow that <br />the vertical height of the embankment doer not exceed five feet at mock pond T-32. <br />• Pleareprovide ride dope information on the new ar-buiftr ro that the Division can determine compliance with <br />Rule 4.05.9. <br />• Pleare indicate that there are ar-builU in the title block for each ojthe impoundment drawingr rubmitted with <br />the TR-35 application. <br />Following revirion to Appendix 13-9, please provide a rtatement cer7~ing that all impoundmentr meet the derign <br />criteria ar rpecified in the approved permit document. <br />Response: This information, including text, drawings, SEDCAD4 printouts, and certifications, is <br />provided in the revised Appendix 13-9 for all proposed permanent stock ponds. New as-built <br />surveys have been submitted for stock ponds T-30 and T-32. All information requested for the <br />ponds has been included. Side-slope infoanation has been included on all drawings. The title blocks <br />have been revised as requested. There will be no temporary stock ponds. The revised appendix 13-9 <br />demonstrates that all the permanent stock ponds meet the design criteria specified in the Regulations <br />of the Colorado Mined Land Reclamation Board (Rule 4.05.9) for permanent impoundment's. Refer <br />also to response to Comment la. <br />Comment Ic: ,Quarterly rtork pond inrpectian reportr jar 2000 and 2001 have been rubmitted ar requerted To <br />enrure tampliana'e Pleare continue to conduct the quarterly inrpectianr in a timely manner. <br />SCC has formally reguerted a variance/waiver from Rule 4.05.9 (17) for all exirting mock pondr. The waiver <br />doer not apply to temporary impoundmenh. The waver rpecifically applier to permanent featurnr derigned for <br />portmine land ure. Pleare determine which impoundmenu will be retained ar a portmining feature, and the <br />Divirian will review the waiver rzgttert for Shore impoundmentr. <br />