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Janice Lynn Bennett - 81422.PDF Page 21 <br />Blasting Impacts Assessment for the Proposed GCC Rio Grande, Inc Quarry in Pueblo County, Colorado <br />H uman Response to Blasting <br />Since the duration of quarry blasts rarely exceed two seconds, the Wiss-Curves (see Figure <br />3.5) indicate that ground vibration, at the nearest offsite dwelling (Blake Ranch) at expected <br />levels around 0.05 inls will be barely detectable. Since blasting is limited by the Pueblo <br />County Special Use Permit No. 1999 -002 to the hours of will occur during daytime <br />hour a.m. to 6:00 p.m., when ambient levels of background noise and vibration are <br />high — especially on an active cattle ranch — neighbors will probably not know when blasts <br />are occurring. <br />Impacts on Animals <br />While visiting the site, the author observed that cows and other farm animals were present <br />on Blake Ranch. Several years ago the author participated in a controlled study regarding <br />the impacts of blasting on a variety of animal species conducted by animal biologists at the <br />Washington Park Zoo in Portland, Oregon. In this study, researchers evaluated the effects of <br />nearby (as close as 500 ft) blasting noise and vibration on black rhinos, naked mole rats, <br />elephants, spotted owls, snow leopards, red pandas and several other species (Shepherdson <br />and Fraser, 1998). Elephantswere specifically chosen for this study because they are known <br />to communicate at infrasonic noise frequencies below human hearing range. The black <br />rhinos were studied because zookeepers were concerned that blasting might aggravate the <br />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 <br />level of the stress hormone (cortisol) found in animal scat, before and after blasting. I n <br />addition, for the first six blasts, the physical reactions of the tested animals were observed <br />when blasting occurred. <br />M aximum 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 <br />first blast or two, however they quickly acclimated to the noise and vibration. Additionally, <br />the black rhinos mated successfully for the first time while construction was occurring on <br />the tunnels. I n their final conclusions, the researchers found that the tested animals <br />experienced no long -term negative effects from the levels of noise and vibration produced by <br />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 <br />the former Atlas Powder Company in Tamaqua, Pennsylvania. The peak air overpressures, <br />during unconfined explosive tests, at that distance often exceeded 145 dBL. When blasts <br />were detonated the deer might casually lift their heads and look toward the test site. <br />However, they never ran away or appeared otherwise bothered by the loud noise. It was <br />obvious that like the animals at the M etro Washington Park Zoo in Portland, the deer had <br />become acclimatized to the blasting noise. <br />1 REVEY Associates, Inc. <br />Page 18 July 2002 <br />