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A written report of the survey will be prepared and signed by the person who conducted the <br />survey. Copies of the report will be provided to the person requesting the survey and to the <br />CDMG. If the person requesting the survey disagrees with the results of the survey, he or she <br />may notify, in writing, both WFC and CDMG of specific areas of disagreement. A list of all <br />completed pre-blast surveys on file can be reviewed in Attachment 2.05.3(8)(a)-1. <br />If, subsequent to a pre-blast survey, a request is made by a resident or owner to survey an <br />addition or renovation to a dwelling or structure within one-half mile of the permit area, such <br />survey will also be conducted in accordance with Rule 4.08.2. <br />Blast Design <br />Prior to the startup of New Horizon Mine, WFC contracting with Vibra-Tech to arrive at an <br />acceptable scale distance factor. Vibra-Tech did a test blast and they determined a starting <br />scale distance factor of 18.04 was to be used at New Horizon Mine. WFC started the blasting <br />program with the 18.04 scale factor. <br />WFC has made it a practice early on to set out numerous seismographs at nearby residences to <br />collect actual seismograph data. As more and more seismic records became available, WFC <br />started modifying the scale distance factor and the blast to reduce vibration and cost. New <br />scale factors were calculated using the OSM Blast Vibration Regression Analysis Program, see <br />Attachment 2.05.3.(6)(a)-2. <br />WFC continues to monitor each blast and modify the blast designs as needed to achieve the <br />necessary fragmentation at the lowest cost, and at the lowest vibration level possible. Burden <br />and Spacing distances, borehole diameter, and different delay sequences have been tried. <br />Each parameter is individually changed so the modification can be monitored and recorded. An <br />elaborate blast design system was developed that took into account: distance to the nearest <br />dwelling/structure, number of free faces for blast energy to dissipate to, material to be blasted, <br />number of blast holes in the pattern, number of holes detonating within any 8 ms period, and the <br />desired degree of breakage. Every shot at New Horizon mine is analyzed before and after the <br />detonation and the knowledge gained is used to continually fine tune the blasting program. In <br />(xa.,taea iz xo., aooz~ 2.05.3(6)(a) 2 <br />