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The Rice Report provides no data or specifications relative the sensitive receptors described in the report <br />and their potential to be damaged by vibration. The Rice Report repeatedly describes the receptors of <br />concem as having been designed for industrial applications. The DMG has evaluated this information in <br />terms of the logical application of equipment design. The limitations placed on blasting vibration <br />imposed by DMG, and agreed to by the applicant, in the MMRR Quarry application, assure that <br />maximum blasting vibration at the location of offsite receptors will be no more than 0.75 inches per <br />second peak particle velocity. 'through reference to a classic study conducted by the United States <br />Bureau of Mines it was determined that vibration levels caused by usual human activities exceed those <br />that will be caused 6y the MMRR Quarry blasting at the receptors of concern. For example, vibrations <br />levels measured by the U.S. Bureau of Mines Far such activities as door slamming, nail hammering, and <br />walking across flooring by heavy-set persons cause vibrations in excess ofone inches per second. In a <br />more recent studyZ investigators determined that door slamming causes vibrations from 0.4? to 1.38 <br />inches per second peak particle velocity, foot stamping causes vibrations from 0.20 to 1.97 inches per <br />second, and that changes in temperature and humidity can cause vibrations of 1.18 to 2.76 inches pct <br />ttecond. The obvious conclusion that can be drawn from these data is that if the sensitive receptors <br />described in the Rice Report are susceptible to damage from the limited blasting vibrations proposed in <br />the MMRR Quarry application, they would be much more susceptible to ordinary daily vibrations <br />resulting from the operations of the facilities, including human access and egtt;ss to the.facilities, truck <br />traffic around the facilities, wind generated vibration, and normal human activities within the facilities. <br />The DMG concludes that the blasting limitations imposed in the current pending application for the <br />MMRR Quarry are protective of the structures owned or otherwise controlled by the Black Hawk/Central <br />City Wastewater Treatment Plant and Silver Dollar Metropolitan District. <br />cc: Bruce Humphries, DMG <br />Carl Mount, DMG <br />Harry Posey, DMG <br />Steve Brown, AGO <br />c:Vbcumrnb and SetmigsWC3VNy IbcumrnbVdMftR blest lraiingAa <br />~ Siskiad, D.E., Stagg, M.S., Kopp, J.W., Dowding, C.H., (1980), Snucrure Response and Damage Produced by Ground <br />Vibration from Surface Mine Blasting, U.S. Bureau of Mines, Report of Invgtigatiom R.I.8507 <br />= I)epartuunt of the Environment TratupoR and the Regions (1998), lTie Environmental Effects ojl>roduction Blasting from <br />Surface Minerol Workings; Her Majesty's Stationary Ofl'ice, United Kingdom <br />