November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

Take the background noise measurement at the mostaffected noise-sensitive location. If responding to anoise complaint, take the measurement as close aspracticable to where the noise impact is alleged tooccur.Measure the background noise in the absence ofboth the noise under investigation and any extraneousnoise not typical of the area. If it is not possibleto exclude the source under investigation, thenmeasure the background noise at a remote locationjudged to have a similar noise environment.Hold the sound-level meter at arm’s length or set itup on a tripod so the microphone is 1.2 to 1.5 mabove the ground and at least 3 to 5 m from walls,buildings and other reflecting surfaces. Duringmonitoring, set the meter to ‘Fast’ time weightingand ‘A’ frequency weighting. Do not take measurementswhen it is raining or when the average windspeed at microphone height exceeds 5 m/s.B2.2 Measurement procedure1. During the period of the day for which thenoise source is expected to operate, determinethe time when the greatest impact is likely tooccur and take measurements at this time.(Note: This is often when the differencebetween the measured background noise andthe noise level generated by the new orexisting development is greatest.)2. Field-calibrate the noise monitoring equipment.3. Measure the background noise level continuouslyfor 15 minutes, excluding all distinctextraneous noises. (Because of the shortperiod over which the background noise isbeing measured, distinct extraneous noises,including noise from transportation, conversation,birds and insects, should be excludedfrom the measurements.) If extraneous noiseis present, pause the meter when this noiseoccurs or choose another measuring time orlocation.The rating background level to be used forassessment purposes is the L A90, 15 minutelevelproduced by a statistical meter.required if there is a calibration drift greaterthan that allowed by the standards.5. If two or more valid measurements of backgroundnoise are recorded at the one location,adopt the lowest level as the backgroundlevel.Note: If the measured background level is less than30 dB(A), then the rating background level isconsidered to be 30 dB(A).B3Reporting requirementsInclude the following items in a report to supportthe determined rating background level:B3.1 Long-term method• details of equipment used (include latestcalibration date), equipment settings andsampling rate of the logger used• a statement justifying the choice ofmonitoring site, including the procedureused to choose the site, having regard to thedefinitions of ‘noise-sensitive location(s)’ and‘most-affected location(s)’ described in Section3.1.2• details of the exact location of the monitoringsite and a description of land uses insurrounding areas• a brief description of where the equipmentwas positioned• a description of the dominant andbackground noise sources at the site• a record of periods of affected data (due toadverse weather and extraneous noise) andstatement indicating the need for any remonitoringunder Step 1 in Section B1.3.• day, evening and night assessmentbackground levels for each day of themonitoring period• the final RBL value.4. Check the field calibration at the end of themonitoring period in accordance withAS1259 and AS2659. Re-monitoring may beNSW industrial noise policy71