Warrawee Substation - Review of Environmental Factors

Warrawee Substation Page 7Operational Noise & Construction Noise & Vibration AssessmentReport No. 11332 Version BThis sound level meter conforms to Australian Standard 1259 Acoustics – Sound Level Meters asa Type 1 Precision Sound Level Meter which has an accuracy suitable for field and laboratoryuse. The A-Weighting filter of the meter was selected and the time weighting was set to “Fast”.The calibration of the meter was checked before and after the measurements with a Bruel andKjaer Type 4231 sound level calibrator and no significant drift was noted.The Bruel and Kjaer Type 2260 and Type 4231 have been laboratory calibrated within theprevious two years in accordance with our in-house Quality Assurance Procedures.Measurement results are shown in Table 3-1. The differences are then used to determineRating Background Level in Winton St as presented in Table 3-2.Table 3-1Results of Attended Background Noise MeasurementsLocationTimeL Aeq,15min, L A90,15min(dBA) (dBA)57 Brentwood Ave 11.45-12.00 50 444 Winton St 12.15-12.30 53 45CommentsBackground noise dominated byhum from distant trafficBackground noise dominated bytraffic from Pacific HighwayBased on the attended noise measurements and the measurement results from the noiselogger, estimated RBL values for residences on the western side of the rail corridor in WintonStreet are 2dBA higher due to the greater exposure to traffic noise from the Pacific Highway asshown in Table 3-2.During our survey, it was noted that there was a combination of wind in the trees and windfrom the direction of the highway, which resulted in higher noise levels measured during ourattended survey than that measured by the loggers.Table 3-2 Measured Ambient Noise Levels from Unattended Monitoring,40 Brentwood AvenueLocationRating Background Level, RBL, dBA L Aeq,period (dBA)Day Evening Night Day Evening Night40 Brentwood Ave 37 40 31 53 52 514 Winton St 39 42 33 56 55 54