Laserfiche WebLink
INITIAL STUDY/MITIGATED NEGATIVE DECLARATION FAIRVIEw BRIDGE REPLACEMENT AND STREET IMPROVEMENTS w <br />MAY 2020 (9TH STREET TO 16TH STREET) PROJECT <br />J" <br />SANTA ANA. CALIFORNIA <br />and other adjacent roadways, and the associated long-term noise level change would not be <br />perceptible above the existing ambient noise level. Therefore, short-term construction -related <br />worker commutes and equipment transport noise level increases would not be substantial. <br />The second type of short-term noise impact is related to noise generated during roadway <br />construction. Construction is performed in discrete steps, each of which has its own mix of <br />equipment and, consequently, its own noise characteristics. These various sequential phases <br />would change the character of the noise generated and the noise levels in the Project area as <br />construction progresses. Despite the variety in the type and size of construction equipment, <br />similarities in the dominant noise sources and patterns of operation allow construction -related <br />noise ranges to be categorized by work phase. Table 3.13.0 lists typical construction equipment <br />noise levels (Lmax) recommended for noise impact assessments based on a distance of 50 ft <br />between the equipment and a noise receptor. <br />Table 3.13.C: Typical Construction Equipment Noise Levels <br />Equipment Description <br />Spec 721.5601 <br />Lmax at 50 ft <br />(dBA) <br />Actual Measured <br />Lmax at 50 ft <br />(dBA) <br />Backhoes <br />80 <br />78 <br />Compactor (ground) <br />80 <br />83 <br />Cranes <br />85 <br />81 <br />Dozers <br />85 <br />82 <br />Dump Truck <br />84 <br />76 <br />Excavators <br />85 <br />81 <br />Flat Bed Trucks <br />84 <br />74 <br />Front -End Loaders <br />80 <br />79 <br />Graders <br />85 <br />N/A' <br />Jackhammer <br />85 <br />89 <br />Pickup Truck <br />55 <br />75 <br />Pneumatic Tools <br />85 <br />85 <br />Pumps <br />77 <br />81 <br />Rock Drill <br />85 <br />81 <br />Roller <br />85 <br />80 <br />Scrapers <br />85 <br />84 <br />Tractors <br />84 <br />N/A <br />Vibratory Pile Driver <br />95 <br />101 <br />Source: Federal Highway Administration Roadway Construction Noise Model (2006). <br />Note: Noise levels reported in this table are rounded to the nearest whole number. <br />1 Maximum noise levels were developed based on Spec 721.560 from the CA/T program to be consistent <br />with the City of Boston's Noise Code for the "Big Dig" project. <br />Z The maximum noise level was developed based on the average noise level measured for each piece of <br />equipment during the CA/T program in Boston, Massachusetts. <br />3 Since the maximum noise level based on the average noise level measured for this piece of equipment <br />was not available, the maximum noise level developed based on Spec 721.560 was used. <br />CA/T = Central Artery/Tunnel Lmax = maximum instantaneous noise level <br />dBA = A -weighted decibels N/A = not applicable <br />ft = foot/feet Spec = Specification <br />R:\WKE1702\ISMND\Final ISMND\Fairview Street Bridge Final ISMND.docx (05/26/20) 3-79 <br />