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Blasting bnpacts and Rock Slope Stability Assessment for Cottonwood Quarry in Grand County,CO <br /> 4.4 Human and Anal Impacts <br /> As established in the prior section, respective vibration and air-overpressure intensities at the <br /> nearest dwellings are not expected to exceed 0.09 in/s and 122 dBL. <br /> Human Response to Blasting <br /> Since the duration of quarry blasts rarely exceed two seconds,the Wiss-Curves(see Figure 3.5) <br /> indicate that ground vibration, at the nearest offsite dwelling,with levels around 0.09 in/s will be <br /> in the barely detectible range. Since Colorado State Rules limit blasting to daytime hours when <br /> ambient levels of background noise and vibration are high, neighbors to the blasting will most <br /> often not even know it has occurred. <br /> Impacts on Animals <br /> While visiting the site, the author observed pastureland, where domestic animals may feed or <br /> range, on adjacent properties. Accordingly, some neighbors might express concerns about <br /> potential blasting impacts on domestic and wild animals. Several years ago the author <br /> participated in a controlled study regarding the impacts of blasting on a variety of animal species <br /> conducted by animal biologists at the Washington Park Zoo in Portland, Oregon. In this study, <br /> researchers evaluated the effects of nearby (as close as 500 ft) blasting noise and vibration on <br /> black rhinos, naked mole rats, elephants, spotted owls, snow leopards, red pandas and several <br /> other species (Shepherdson et al, 1998). Elephants were specifically chosen for this study <br /> because they are known to communicate at infrasonic noise frequencies below human hearing <br /> range. The black rhinos were studied because zookeepers were concerned that blasting might <br /> aggravate the problems with a pair that was unsuccessful at breeding during the year prior to the <br /> construction work. The physiological effects of blasting were evaluated by measuring the level <br /> of the stress hormone (cortisol) found in animal scat, before and after blasting. In addition, for <br /> the first six blasts, the physical reactions of the tested animals were observed when blasting <br /> occurred. The intensity of blast-induced ground motion in this study was as high as 0.68 in/s, <br /> which is more than 7 times higher than the 0.09-in/s level expected for the Cottonwood Quarry. <br /> Maximum air overpressure for this blasting was about 130 dBL (Linear scale) and ground <br /> motion reached about 0.25 in/sec. The researchers noted that the tested animals noticed the first <br /> blast or two,however they quickly acclimated to the noise and vibration. Additionally,the black <br /> rhinos mated successfully for the first time while construction was occurring on the tunnels. In <br /> their final conclusions, the researchers found that the tested animals experienced no long-term <br /> negative effects from the levels of noise and vibration produced by the construction blasting. <br /> From the authors' personal experience, white-tailed deer were observed, on many occasions, <br /> within several hundred feet of an open-air explosive testing range at the Reynolds Plant of the <br /> former Atlas Powder Company in Tamaqua, Pennsylvania. The peak air overpressures, during <br /> unconfined explosive tests,at that distance often.exceeded 145 dBL.When blasts were detonated <br /> REVEY Associates,Inc. Page 16 April 2004 <br />