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5. Response to Adequacy Question #5 <br />In their 1 1/29/Ol study, Matheson Mining Consultants, Inc, (MMC) determined the distance <br />between each seismograph used and the three corresponding test blasts (Appendix IV table, <br />"Distance" column). MMC then scaled (norntalized) these distances by dividing the <br />distances by the highest recorded weight of explosive in any one hole for each of the three <br />blasts (Appendix N table, "Scaled Distance" column). <br />MMC then listed the peak particle velocities recorded at each of the seismographs following <br />each of the three blasts (Appendix IV table. "Peak Particle Velocities"), and then plotted <br />these velocity values versus values of scaled distance for each of the seismographs on log- <br />log paper. <br />Using this plot, known as a regression analysis, MMC then determined that [he Scaled <br />Distance value corresponding to the Peak Panicle Velocity value of 1.0 inches per second <br />was 28.44 (Appendix V). This 28.44 value is the Scaled Distance Factor value that Seneca <br />Coal Company proposed to be used at the Yoast Mine instead of the Scaled Distance Factors <br />described in CMLRB Regulation Section 4.08.4(10). <br />During [heir ground motion attenuation study, MMC moved [en of the eleven seismographs <br />following the detonation of the first test blast, and repositioned these ten instruments to <br />record ground motions from the second and third test blasts. I had a concern that <br />repositioning the seismographs after the first test blast might have created a different <br />statistical set of data, so I asked the permittee to re-plot their data on two new log-log plots, <br />plotting the data from just the first blast on one graph, and plotting the combined data from <br />the second and third test blasts on a second graph. <br />The permittee submitted these new graphs (revised Appendices III and IV) in their response <br />of I/IS/02. The Scaled Distance Factors derived fiom these two new plots are 34.85 (from <br />the data derived from only the first test blast) and 28.26 (from the combined data from the <br />second and third test blasts). While the newly-derived Scaled Distance Factor value of <br />28.26 for the plot from Shots 2 and 3 is practically identical to the initial 28.44 value derived <br />from plotting [he data from all three blasts together, the newly-derived value of 34.85 value <br />for [he Shot Number l data is a more conservative value. <br />MMC has stated that the two new regression analyses each do not contain enough data <br />points to be statistically valid. While this may be true, MMC themselves created a degree of <br />statistical variability in their study that could have been avoided if they had left the <br />seismographs in place for the second and third blasts. As such, I believe it is in the best <br />interests of the Division, in ensuring the protection of the Yoast and Valora residences, to <br />request the permittee revise its proposed Scaled Distance Factor value from 28.44 to 35. I <br />therefore recommend the following adequacy question: <br />5. The Division has reviewed the two new regression analyses derived from <br />plotting the data from Shot Number 1, and from plotting the combined data <br />from Shots 2 and 3. According to the 1/15/02 Seneca Coal Company response, <br />