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Blasting Impacts Assessment for the Proposed GCC Rio Grande, Inc. Quarry in Pueblo County, Colorado <br />blast noise and vibration levels have been as high as 0.08 in/s and 128 dBL, respectively. Despite <br />initial concerns by the dairy operators, all involved parties have now concurred that the cows have <br />not been disturbed in any way by these blasting effects. <br />At the Red Rock site, all domestic animals located more than 4,000 feet from planned blast areas <br />will experience maximum levels of ground motion of around 0.05 in/s [240(4,000/(360) 0.5y1.6]. <br />Intensities of air - overpressure for 6.75 -inch charges, stemmed with at least 6 feet of crushed stone <br />stemming, will likely not exceed 115 dBL at distance greater than 4,000 feet. Based on the <br />referenced studies and observations of the author at many other projects, blasting at the Red Rock <br />Project will have little or no impact on domestic animals at the Blake Ranch or at other more <br />distant neighboring properties. <br />4.5 Control of Dust <br />In provisions contained in the GCC Air Permit, Construction Permit No. 98PB0893, requirements <br />are in place to use water injection when drilling to control drilling dust, and sequential delay <br />timing schemes to minimize blasting dust. Further, since limestone quarry operators like GCC Rio <br />Grande invariably remove loose overburden to prevent dilution of mined rock, it unlikely that <br />airborne dust from blasting will be a cause of concern. <br />4.6 Impacts on Soil Resources <br />Some small amounts of blasting agents, which in quarries is typically ammonium nitrate pellets <br />mixed with fuel oil (ANFO), is lost to the ground by spillage or wind blowing while being loaded. <br />The amount on nitrates released to the ground by these losses is typically not toxic to any flora or <br />fauna in an arid environment like that existing at the Red Rock site. Wind -blown ANFO dust that <br />lands on the ground surface effectively becomes fertilizer for plants that convert it to other natural <br />matter through photosynthesis. This amount of nitrates from this source is usually much less than <br />that created by mass fertilizing of agricultural crops or nitrates produced from urea in animal <br />urine. GCC Rio Grande should, consistent with good practices for minimizing spillage, <br />implement careful clean-up procedures to ensure that no large spills (> 0.5 lb) of ANFO are left on <br />the ground, concentrations of nitrates or ammonia will not be harmful or even noticeable. <br />REVEY Associates, Inc. Page 16 July 2002 <br />