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E~x erimental Site: Already answered in response to Flinn Letter. <br />Data Analysis Procedures: All data analyses have been done with strict conformance to <br />standard engineering and statistical practices. In fact, by using upper 95% probability <br />calculations, the author has used "worst case" projections to support all calculations and <br />conclusions in the subject study. <br />Field Procedures and Instrumentation: Field monitoring procedures used for all monitoring <br />work done by PreSeisTek, Inc. have been provided in Attachment I. Specifications for the <br />Instantel MiniMate Plus instruments used to perform this work are provided in Attachment <br />II. The instruments also perform sensor response tests just prior to monitoring when used in <br />the field to ensure they are operating properly. If not, problem sensors are identified in event <br />reports. These instruments are calibrated yearly by the Instantel, the manufacturer. The <br />author has carefully studied all the event reports is very confident that they are accurate. <br />E~x erimental Site: Already answered. <br />Data Analyses: All curves were developed using standard linear regression methods. Other <br />scientists using standard linear regression formulas would obtain exactly the same site <br />constants from the measured data. Curves have not been manipulated in any way and the <br />method of calculated the upper 95% curves is based on the standard deviation of the data <br />and standard statistical probability methods. The key extrapolation calculation done in the <br />study was for a distance of 340 feet, the closest distance of operating bull dozers. Since <br />measurements were made at 150 feet, this is not unreasonable. More important, PreSeisTek <br />did attempt to make measurements at greater distances but the intensity of motions at greater <br />distances were not even measurable with instruments set to measure particle motions as low <br />as 0.005 in/s. No extrapolation calculations were done for the crusher at a distance of 900 <br />feet as inferred by Mr. Lazear. <br />Discussion of Different Wave Types: While having a very good understanding of varying <br />types of body and surface vibration waves, the author did not include a technical summary <br />of their general characteristics because the vibration monitoring data accounts for all particle <br />motion caused by the complex interactions of all wave types. Since measurements were <br />done for 5-second time durations, particle motion caused by compressive waves, shear <br />waves, Rayleigh waves, even refracted or reflected waves, is accounted for in the <br />measurements. Moreover, only the peak or highest particle motion measured during the 5- <br />second time duration has been reported and used in the analyses. <br />Harmonic Motion: The vibration time-history plots for the monitoring done for this study <br />clearly show that the steady-state ground motion created by mechanical mining equipment is <br />very near harmonic. Hence, the industry standard practice of using motion equations based <br />on simple harmonic motion is very appropriate in this case. <br />REVEY Associates, Inc. Page 3 of 13 4/19/06 <br />