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Review of Blasting Operations of Summit Brick ANALYSES of BLASTING IMPAC'T'S, cont' Therefore : SD = 1300 ft./1b~~2 SD(@1300 ft) = 1300 /335.66 = 3.872 At this scaled distance, using conservative response constants in the vibration prediction formula shown in equation 2. 1, the ground motion at the nearest structure would be around 0.0273 in/sec. ppv (@ 1300 ft) 300 (1300)-16= .0273 in/ sec Now, the damage threshold limit is 1.0 in/sec, the above calculation shows that the intensity of motion is much less than the limit. More distant dwellings or structures would have values less than that of the Hanratty house since further attenuation would take place. Blast induced ground motion associated with the Summit brick mining operations would not cause vibration damage to adjacent structures or property based upon the above data. 2.1-3 Potential for Blast Damage to Area Water Wells: Water wells nearest to the permitted blasting area have been plotted in Figure ].1. Well is the nearest well. The distance between this Well and the nearest boundary of the permitted blasting area is approximately 1,400 feet. The condition of this well is unknown. In a major study contracted by the United States Bureau of Mines (USBM, Berger et al., 1980 and 1982), the researchers published the following review of vibration effects on water wells. "The background review found little that was directly appluabfe. Observed cases of well damage were caused by permanent ground displacement, such as land sliding; rather than vibration. The types of effects observed required vibration levels many orders of magnitude higher than typical blasting vibrations and were listed as "casing collapse, earth displacement, pump base displacenunl, misalignmerst of pump column. " eu. Cases specifically involving mining were concerned with pit excavations and included interception with the aquifer, pumping from bit bottoms, and ground water pollution. ]6