November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

has shown that it is a reasonable approach toassessing intrusive noise impacts.In some rural situations, the rating backgroundlevel may be the same for the day and night. In thesecases, it is recognised that excursions of noise abovethe intrusiveness criterion during the day wouldnot usually have the same impact as they would atnight. This is due to the more sensitive nature ofactivities likely to be disturbed at night (for example,sleep and relaxation).2.2 Protecting noise amenityTo limit continuing increases in noise levels, themaximum ambient noise level within an area fromindustrial noise sources should not normallyexceed the acceptable noise levels specified in Table2.1. Meeting the acceptable noise levels in Table 2.1will protect against noise impacts such as speechinterference, community annoyance and, to someextent, sleep disturbance. These levels representcurrent best practice for assessing industrial noisesources, based on research and a review of assessmentpractices used overseas and within Australia.Table 2.1 also includes recommended maximumnoise levels for different land uses. These recommendedmaximum values provide guidance on anupper limit to the level of noise from industry. In allcases it is expected that all feasible and reasonablemitigation measures would be applied before therecommended maximum noise levels are referenced.In some instances it may not be possible to achieveeven the recommended maximum noise level, evenafter all feasible and reasonable noise mitigationhas been applied. Such cases are expected to have alarge adverse noise impact. Where a proposeddevelopment exceeds the recommended maximumnoise levels in Table 2.1, substantial benefits in otherareas, including a high degree of social worth,would need to be demonstrated.Where the existing noise level from industrial noisesources is close to the acceptable noise level, thenoise level from any new source(s) must be controlledto preserve the amenity of an area. If the totalnoise level from industrial sources already exceedsthe acceptable noise level for the area in question,the L Aeqnoise level from any new source should notbe greater than:• 10 dB below the acceptable noise level if thereis a reasonable expectation that existinglevels may be reduced in the future; or• 10 dB below the existing level if there is nosuch reasonable expectation that existinglevels will fall (for example, in cases wheresurrounding areas are fully developed) andno significant changes to land use areexpected.Table 2.2 sets out the implications of this requirementfor noise from industrial sources.Adjustments are to be applied to the source noiselevel received at the assessment point, before comparisonwith this criterion, where the noise sourcecontains annoying characteristics such as prominenttonal components, impulsiveness, intermittency,irregularity and dominant low-frequencycontent, as outlined in Section 4.Procedures for considering meteorological effectssuch as temperature inversions and wind areoutlined in Section 5 to account for characteristicweather conditions under which the amenitycriteria apply.In determining the existing L Aeqnoise level fromindustry, noise from transportation-related sources(road traffic, rail traffic and aircraft) may be excluded.Criteria for noise from these sources aredefined separately. Research and experience indicatesthat residents distinguish and respondseparately to noise from road traffic, rail traffic,aircraft and industrial sources, rather than registeringan overall noise annoyance related to the totalL Aeqnoise level. Section 3.2 gives guidance on how todetermine existing noise levels. Practical means bywhich transportation noise (road traffic in particular)may be excluded from a measurement of existingnoise levels are presented in Section 3.2.1.Where existing traffic noise levels are continuouslyhigh, the existing level of the traffic noise (determinedby using the method outlined in Section 3.2)can be 10 dB or more above the recommendedacceptable noise level shown in Table 2.1. In thesesituations the industrial source may be inaudible,even where it produces noise levels higher than theacceptable noise level. The criterion to be applied inthis case is set out in Section 2.2.3.NSW industrial noise policy15