SU0007300 - Laserfiche WebLink

Home Browse Search

For single-event noise, the probability of awakenings due to project haul truck operations on East River Road was calculated to be approximately 89-93 percent for residences 60 feet from the centerline of the roadway. The lower probability (89 percent) is related to the application of proposed optimized truck operating parameters, with the upper probability (93 percent) assuming typical operations. The probability of awakenings was calculated to be 99-100 percent when the cumulative effects of existing vehicle traffic and project haul trucks on East River Road are combined. The increase in probability of awakenings due to the project haul trucks was calculated to be 7-8 percent. This level of increase is considered significant. Mitigation: Measure 3.4.1: All project trucks shall be operated using noise-mitigating operating parameters when entering or leaving the plant on East River Road. Based on testing conducted by Bollard Acoustical Consultant, Inc., the quietest haul truck operating parameters were as follows. • Empty Trucks: Travel speed at 38-43 mph with engines in 81"gear at 700-800 rpm. • Loaded Trucks: Travel speed of 33-35 mph with engines in 61" or 7" gear at 1,400-1,600 rpm. Furthermore, truck parking anywhere along River Road and the use of jake brakes at the McHenry Ave/E. River Road intersection and the E. River Road/project driveway is prohibited. The applicant shall monitor full time for compliance with these requirements beginning 30 minutes prior to any approved extended hour operations. Significance After Mitigation: Application of the proposed optimized haul truck operating parameters in Mitigation Measure 3.4.1 would be expected to effectively mitigate project-related noise exposure from the perspective of the applicable County noise exposure level criteria and noise exposure level increase criteria (as described by the Ldp). However, application of the optimized haul truck operating parameters would not appreciably mitigate the significant increase in probability of residential awakenings due to project haul truck operations (single-event noise). Due to the significant increase in probability of residential awakenings in the project area due to project haul truck pass-bys, this impact is considered significant and unavoidable. San Joaquin County QX-89-0002/Aggregates Inc. Community Development Page 8