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Response to CN-01 Preliminary Adequacy Issues for a 112(d) Application <br />6.5 Geotechnical Stability <br />W= (D/SDF)2 <br />Where <br />W=weight in pounds of detonated explosive in any period greater than 8 <br />milliseconds. <br />D=is distance in feet from the structure of concern <br />SDF=Scaled Distance Factor <br />As an example <br />If a structure is 200 feet away from the blast site, the maximum amount of explosives per <br />delay is 16 pounds without the need for a seismograph. Typically 5 to 10 pounds of <br />explosives will be used at any one time on the road cuts where the nearest structure will be <br />in excess of 400 feet. . <br />Blasting noise is the release of excess energy. Excessive noise can be created if <br />• there is too much energy for rock conditions, <br />• release of energy through broken ground and existing rock fracture <br />• improper stemming or poor stemming materials. <br />The release of excess energy is a waste of energy. To eliminate waste, and to comply with <br />applicable regulatory guidelines, the May Day Idaho Mine Complex will conduct small <br />initial blasts. During the initial phases, May Day Idaho Mine Complex personnel will <br />conduct seismograph and noise monitoring when blasting will be conducted within 400 feet <br />of existing manmade structures to verify empirical formulas and to demonstrate <br />compliance with applicable noise criteria. <br />It is recommended and Wildcat has agreed "that vibration monitoring be utilized if the size of the <br />blasts ever reaches the unlikely amount of 220 pounds of explosive per delay to provide more <br />accurate prediction of potential vibration damage." The contractor to conduct daily blasting is <br />Franklin Drilling & Blasting under the permits identified in Attachment G <br />00000 <br />J. Erich Rauber <br />Colorado P.E. 26647 <br />Principal-R Squared, Inc. <br />May Day Idaho Mine Complex 112(d) Permit Application <br />Revised: April 14, 2011