November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

3. Control in transmission—the next beststrategy to controlling noise at the source—itserves to reduce the noise level at the receiverbut not necessarily the environment surroundingthe source.4. Receiver controls—the least-preferredoption, as it protects only the internal environmentof the receiver and not the externalnoise environment.Proponents will take into account the cost-effectivenessof strategies in determining how much noisereduction is affordable. A proponent’s choice of aparticular strategy is likely to have unique featuresdue to the economics of the industry and sitespecifictechnical considerations.The above steps and the range of measures describedin the chapter can be used as a guide inassessing the strength of the proponent’s mitigationproposals.Where a proposed mitigation strategy will notachieve the desired noise reduction and leaves aremaining noise impact, the problem needs to besolved by negotiation. The negotiation process is thesubject of Section 8.7.6 Managing short-term exceedanceof approved noise levelsFrom time to time, managing noise at the source mayrequire a short-term increase in noise beyond thelevel approved. Such situations may include:• running-in new equipment• abnormal operations due to unforeseenbreakdown or maintenance requirements• occasional needs to move heavy equipment tonew locations on site.Mitigation strategies are often impractical for suchshort-term events.The noise-source manager should demonstrate thatall alternatives to noisier operations have beenconsidered before seeking an accommodation fromthe relevant regulatory/consent authority to operatein excess of the agreed noise levels. If it is judgedthat such an accommodation for a short-term noisieroperation is warranted, the following options couldbe considered:• confining noisier operations to the leastnoise-sensitivepart of the day—which wouldbe when the background noise is highest• determining an upper level for noise impact• consulting with the community regarding theproposed events.7.7 Generic noise control measuresTypical noise sources on industrial sites include:• engines• exhausts• fans• transport of materials, such as on conveyorsand trucks• milling and stamping (metal works)• sawing and debarking (wood mills)• processors such as crushing and separating• pumps and compressors• whistles and alarms• material dumping and scraping• electrical transformers and switchingequipment.The choice of noise control measures depends onboth the degree of mitigation required and theundesirable characteristics of the noise source thatneed to be controlled. The actual measures chosenwill also depend on site factors, such as the abilityof the site to accommodate particular engineeringmeasures relative to other measures and their sitecosts.A generic set of noise-control measures is set outbelow, with additional measures shown thatrespond to particular developments.Generic list of mitigation measuresNoise-source controls• enclosing the source—the design of theenclosure and materials used to absorbsound will affect the attenuation achievedNSW industrial noise policy41