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As mentioned above, it is recommended that Seneca Coal Company utilize a revised Scaled <br />Distance Factor of 35 for distances of 301 to 5000 feet. It is additionally appropriate that the <br />permittee propose the two additional Scaled Distance Factors (for less blasting within 300 <br />feet of ,and for over 5000 feet from, protected structures), rather than give us a set of tables. <br />I therefore recommend the following additional adequacy question: <br />6. The Division has reviewed the data submitted in Appendices V and VI. <br />However, the Division believes that it is more appropriate, for the purposes of <br />the permittee's DMG permit, that the permittee identify in the text of its permit <br />all three proposed Scaled Distance Factors, in a format similar to the table in <br />Rule 4.08.4(10). <br />As mentioned in our new Adequacy Question #5 above, the Division believes <br />that the regression analysis developed for the data from only Shot Number 1, <br />which developed a Scaled Distance Factor of 34.85 at 1.0 ips, should be the <br />analysis used in calculating the Scaled Distance Factors at 0.75 ips and 1.25 ips. <br />Please provide, with appropriately revised text, these two new proposed Scaled <br />Distance Factors, ensuring they are derived from the 95% confidence level <br />equation developed from the Shot Number 1 data (PPV=326.4 X (SD)^ t'6' ). <br />7. Responses to Adequacy Question #7 <br />The spacing (distance between shot holes generally measured in a direction parallel to the <br />longest tree face) of the three [es[ blasts was 28 feet. The permittee, in its proposed permit <br />text, indicates that it intends to using a spacing distance of 35 feet between blast holes. <br />Increased spacing distance can, though not always, cause increased energy confinement, <br />which in tum can increase ground vibration. The permittee acknowledged this, and stated <br />that "close attention should be paid to seismic monitors at the nearest residences to ensure <br />compliance". I therefore recommend the following comment to the permittee: <br />7. Seneca Coal Company's response to this item included the following sentence: <br />"If the spacing is increased from 28 feet, close attention should be paid to <br />seismic monitors at the nearest residences to ensure compliance". Please revise <br />this sentence to read, "If the spacing is greater than 28 feet, close attention will <br />be paid to seismic monitors at the nearest residences to ensure compliance", and <br />place this sentence in text that will be placed into the DMG permit. <br />8. Response to Adequacy Question #8 <br />The Division requested the permittee propose some level of seismic monitoring at the three <br />nearby residences when utilizing their proposed modified Scaled Distance Factors. The <br />permittee has committed to continuous monitoring at two of the three residences, stating that <br />monitoring at the third residence won't be necessary as it lies just beyond one of the <br />structures they will monitor. <br />