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The log for Blast #104-02 indicates that 13,353 lbs of explosives were used to fill the holes drilled <br />for the blast, that the blast had 72 holes, and that the average weight of explosives per hole was 185 <br />lbs/hole (13,353 lbs/72 holes). The blast sketch for this blast indicates that 75 holes were actually <br />drilled (and presumably all filled with explosives). By dividing 13,353 lbs by 75 (rather than 72), I <br />calculated the average weight of explosives placed into each hole to be 178 lbs/hole. <br />The maximum number of holes detonated within any 8-ms interval during Blast #104-02 is <br />recorded on the blast log as 5. The value for the maximum weight of explosives detonated within <br />any 8-ms interval during the blast is recorded as 925 lbs(8 ms, which the log indicates LCC derived <br />by multiplying their value of the average weight of explosives per hole of 185 lbs/hole by LCC's <br />value of 5 holes detonated per 8-ms interval during Blast # 104-02. <br />By reconstructing Blast #104-02 from its blast sketch, I determined that the maximum number of <br />holes that were detonated within any 8-ms interval was 4. Multiplying my calculated value of 178 <br />lbs of explosives/hole by my value of 4 holes detonated during any 8-ms interval, I calculated the <br />maximum weight of explosives detonated within any 8-ms interval during Blast # 104-02 was 712 <br />lbs/8 ms. <br />My calculated value of the maximum amount of explosives detonated per 8-ms interval during Blast <br />#104-02 of 7121bs/8 ms is less than LLC's calculated value of 925 lbs/8 ms. Both values, however, <br />are less than the State limit of 61121bs/8 ms that I determined to be applicable to Blast #104-02. <br />Rule 4.08.4(10) indicates that for distances from 301 feet to 5000 feet between blasts and the types <br />of structures described in the rule, the maximum allowable ground vibration at the neazest protected <br />structure, measured as peak particle velocity (PPV), is 1.0 inches per second (ips). The rule <br />additionally indicates that for distances between blasts and protected structures of 5001 feet and <br />greater, the PPV limit is 0.75 ips. <br />The log for Blast #104-02 indicates the distance between the Primero School and the blast was 5300 <br />feet. This would indicate that the maximum ground vibration allowable by Rule 4.08.4 (10) would <br />have been 0.75 ips. However, a review of the information provided by Mr. Smith on 6/4/02 <br />indicates the distance between the school and the blast was 4300 feet. Using the smaller distance, <br />the maximum ground vibration allowable by Rule 4.08.4(10) at the Primero School for Blast #104- <br />02 would have been 1.0 ips. <br />According to the log for Blast #104-02, a seismograph was located 1000 feel to the north of the <br />blast. A check of the seismograph's distance from Blast #104-02, based upon the information <br />provided by Mr. Smith on 6/4!02, indicates the distance from the seismograph to the blast was <br />approximately 1050 feet. The log indicates that the seismograph recorded a maximum ground <br />vibration level of 0.09 ips. <br />According to information provided by Mr. Smith on 5/29/02, the seismograph microphone had a <br />low end frequency of 2 Hz; as such, the maximum level of airblast allowed by Rule 4.08.4{6)(a) at <br />the Primero School would have been 133 dB. According to the log for Blast #104-02, the <br />seismograph used to monitor Blast #104-02 recorded a value of 120.6 dB. <br />