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• The log and blast sketch indicate that surface delays between rows were 42 ms. The permit <br />states that surface delays between rows will be 100 ms. <br />• The log indicates that downhole delays were 350 ms. The permit states that downhole delays <br />will be 600 ms. <br />• Based upon my reconstruction of the blast, there were no instances of two or more blast holes <br />detonating simultaneously. There were, however, 62 instances of two or more blast holes <br />detonating within 8 ms of each other. The permit states that all blast holes will have a 9-ms <br />delay between them, and indicates that each blast hole will be detonated sequentially. <br />Blast #108-02 <br />The log for Blast #108-02 indicates that the blast was initiated at 1:06 pm on S/23/02. The log <br />indicates that the distance between the blast and the Primero School was 5700 feet. The <br />information provided by Mr. Smith on 6/4/02 that identifies the location of that blast on a mine <br />map, however, indicates the distance between that blast and the Primero School was 3775 feet, <br />when used in conjunction with LCC Map 2.05.03-4 "Surface Blasting Area" (certified 7/30/01). <br />The distance between Blast #108-02 and the rockfall azea is estimated at 4900 feet, based upon the <br />information provided by Mr. Smith on 6/4/02, and my estimate of the location of the rockfall azea. <br />The log for Blast #108-02 indicates that LCC determined that the maximum allowable weight of <br />explosives that the State's regulations allowed LCC to detonate within any 8-ms interval during this <br />blast was 10,609 lbs/8 ms. The log indicates that LCC obtained this value by dividing their 5700- <br />foot distance value by the scaled-distance factor from Rule 4.08.4(10) of SS, rounding this value <br />down to 103, and squazing this result. <br />LCC's use of the scaled-distance factor of S S appears to have been incorrect, however, as that value <br />is used for distances between blasts and protected structures that range from 301 to 5000 feet, and <br />as LCC had estimated the distance between Blast #108-02 and the school as 5700 feet. <br />Using my estimated value of 3775 feet, and dividing that value by the scaled-distance factor of 55 <br />as prescribed by Rule 4.08.4(10), not rounding the result, and then squaring the result, I calculated <br />that the maximum weight of explosives per 8-ms interval allowed for Blast #108-02 by the State's <br />regulations would have been 4711 lbs/8 ms. This is lower that LCC's calculated value. <br />The log for Blast #108-02 indicates that 19,7141bs of explosives were used to fill the holes drilled <br />for the blast, that the blast had 87 holes, and that the average weight of explosives per hole was 226 <br />lbs/hole (19,7141bs/87 holes). A review of the blast sketch indicates that these values appeaz <br />correct. <br />The maximum number of holes detonated within any 8-ms interval during Blast #108-02 is <br />recorded on the blast as 3. The value for the maximum weight of explosives detonated within any <br />8-ms interval during the blast is recorded as 678 lbs/8 ms, which the log indicates LLC derived by <br />multiplying their value of the average weight of explosives per hole of 226 lbs/hole by LCC's value <br />of 3 holes detonated per 8-ms interval during Blast #108-02. <br />