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Susan Burgmaier -5- June 12, 2014 <br />27. Response accepted. <br />28. Response accepted. <br />29. Response accepted. <br />30. DRMS: BRL provided the design information as requested. The previously submitted <br />East Clean Water Diversion designs included an add -on table to indicate how the flow <br />value was derived for each segment of the ditch. The table identified the source and flow <br />of all areas contributing to the ditch. Please revise pages B -67, 5-72, and B -73 to <br />retain the previously proposed flow derivation information that explained the <br />total flow value used for each of the East Clean Water Diversion segment <br />designs, <br />a. New Item — The flow value used for the 1% segment of the East Clean Water ditch <br />appears to be in error. The Sedcad run on page B -74 indicates that the flow for the <br />watersheds draining directly to the ditch will be 2.92 cfs. Adding that to Drainage <br />Area D (3.47 cfs), W Diversion Ditch #1(4.44 cfs) and the Mine Water Discharge (0.5 <br />cfs) indicates a total fl ow of 11.33 cfs. Please verify the flow value used for the <br />1 % segment ofthe East Clean Water Diversion and revise the channel size <br />accordingly, <br />B W2: Please remove from consideration all items pertaining to the Clean Water Ditch. <br />A new revision application (TR88) has been submitted to address Clean Water Ditch <br />design and adequacy items. <br />31. Response accepted. <br />32. DRM Buckhorn's response, while it does include a single block failure analysis, <br />fails to make a compelling argument for excluding total strength (Undrained) conditions <br />from consideration and does not discuss the dissipation (or lack thereof) of pore <br />pressures. The Mar -2007 Buckhorn report is the stability analysis for Gob Pile #3 <br />currently approved in the permit, and any proposed changes to the models and <br />variables evaluated in that report should be accompanied by a thorough rationale that <br />references the original study and incorporates any new information. Please address <br />the requirements of Rule 4,10,4(2) (minimum static factor of safety of 1,5) <br />for the proposed reconfiguration of Gob Pile #3 including a consideration of <br />Undrained conditions resulting from a lack of dissipation of pore pressures. <br />Alternatively, a detailed rationale supporting elimination of Undrained <br />analyses from consideration maybe provided. <br />