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• • <br />allowances for construction of projects such as the Yankee Gulch Project. Such <br />• projects are subject to the maximum permissible noise levels specified for Industrial <br />zones. <br />Background Noise Levels <br />Noise monitoring near Meeker, Colorado, was conducted in the early 1980s in <br />conjunction with the oil shale projects on the West Slope. The highest background <br />measurement near the Piceance Site was 45 db(A). This level is well below the <br />permissible Colorado noise standards for Residential zones. Noise levels that are <br />representative of the ambient background for the region are discussed in Section <br />7.13. <br />Projected Noise Impacts <br />Comparison of the estimated maximum noise levels listed in Table S-2 for the <br />proposed Yankee Gulch Project with the ambient noise standards listed in Table 8-3 <br />indicates that the impacts will generally be within Industrial zone standards. <br />Residential zone standards are likely to be exceeded for both daytime and nighttime <br />conditions. However, the nearest residence is about 1 mile from either the Piceance <br />Site or the preferred Parachute Site. Using the attenuation estimate of 6 db(A) for <br />each doubling of the distance from the source, the noise generated by heavy-duty <br />• truck travel from either the Piceance Site or the Parachute Site would be sufficiently <br />attenuated to permissible daytime Residential zone levels [55 db(A)] at about 0.3 <br />mile. It would drop below background noise levels [45 db(A)] in approximately 1 <br />mile. Noise generated by Yankee Gulch Project construction activity should drop to <br />allowable daytime Industrial zone levels [80 db(A)] at a distance of 300 feet from the <br />activity. <br />Table 8-2 Estimated Noise Levels 50 Feet from Source. <br /> <br />Equipment Maximum Noise Level <br />[db(A)] Daily <br />Operation <br />Cars, pickup trucks 55 to 80 Intermittent throu hout 24 hours <br />Heavy trucks 85 Intermittent, mainl daytime <br />Boiler (fan) ' 90 24 hours <br />Electricity eneratorsl 90 Intermittent <br />Dryer fan 90 24 hours <br />Pumps' 85 to 90 24 hours <br />Compressors` 85 to 90 24 hours <br />Conveyors (dryer) 85 to 90 24 hours <br />Construction activity 100 Transient, mainly daytime <br />• Noise will be dampened to negligible levels by enclosure of the source. <br />Amencan Soda, L.L.P. 8_34 <br />Commercial Mine Plan <br />August I8. 1998 <br />