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6. the desired Peak Particle Velocity (PPV) limit <br />Blasts at the NH2 Mine near dwellings are analyzed before and after the detonation, and that <br />information is used to continually fine tune the blasting program. WFC will use this NH2 data, <br />rather than one of the generic Scaled Distance factors shown in Table 2.05.3(6)(a) -1, to design <br />the blasts at New Horizon North. An example of the analysis conducted at NH2 that is used to <br />determine the modified Scaled Distance is in Appendix 2.05.3(6)(a) -2. The methodology used is <br />from the Office of Surface Mining Blasting Guidance Manual - Compliance Option 3: Modified <br />Scaled Distance2. <br />The modified Scaled Distance at NH2 is determined by inputting the PPV from previous blasts <br />into a spreadsheet based off of the OSM Regression Analysis programs from the OSM Blasting <br />Guidance Manual. This input data is used to calculate a regression curve at a 95% confidence <br />interval. The regression curve allows the blast designer to determine a site specific ( "modified ") <br />Scaled Distance for a desired PPV. Using the modified Scaled Distance (around 48 ft/lb), the <br />weight of explosives (W) in a blast design is calculated using the formula W = (D /DS)2. This <br />allows WFC to design more effective blasts than with the table Scaled Distance values, while <br />still protecting nearby structures. The PPV limits used to determine the modified Scaled <br />Distance are the same or less than the PPV limits in Table 2.05.3(6)(a) -1. <br />The analysis of near dwelling blasting conducted at New Horizon 2 will allow safe blasting within <br />500 feet of any structure at New Horizon North. <br />As per Rule 4.08.1(4)(a), see Appendix 2.05.3(6)(a) -4 for blaster- certified shot patterns. <br />5.0 Production <br />Rule 4.08.4(10) <br />Bagged or dry ANFO explosive will be used at different times to properly fracture the <br />overburden at the NHN Mine. Powder factors will vary with each shot due to ever changing <br />geologic rock formations. Powder factors for each shot will be selected after the following <br />2 OSMRE Blasting Guidance Manual. Rosenthal, Michael F. & Morlock, Gregory L. March 1987 <br />SECTION 2.05.3(6)(a) PAGE - 5 - JULY 2013 <br />r/1 -02 <br />"IpQ-0vid <br />/7'Ia/ .2.013 <br />