November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

Cowal Gold Project – Noise Management Plan5.2.3 Operation Noise ImpactsThe modelling procedure applied to the operation phase to ascertain noise effects on dwellings andbird breeding was the same as that applied to the construction phase. The following sections outlinethe results of noise emission modelling during operation for both nearby dwellings and bird breedingareas.Comparison with construction noise intrusive criteria (Table 1 - L A10(15 minute) ) has been made whichpre-dates the operations intrusive and sleep disturbance criteria derived in accordance with the INP(Table 2 - L Aeq(15 minute) ) and DEC requirements (Table 2 - L A1(1 minute) ), respectively.DwellingsTable 9 indicates that at all the closest dwellings, the predicted noise levels comply with daytime andnight-time level criteria (Table 1) under neutral and adverse conditions.Table 9Predicted L A10 Noise Contribution - OperationDwelling NameNeutral MeteorologicalConditions3 o C/100 m Inversion 1.5 m/s WindYear 3 Year 8 Year 3 Year 8 Year 3 Year 8Coniston 11 21 22 27 26 31Lakeside 10 19 20 24 23 28Lake Cowal 14 13 20 19 22 22Gumbelah 9 11 16 15 17 17After: Richard Heggie Associates, 1997Bird BreedingProject operation noise levels under adverse conditions (1.5 m/s wind) were predicted at variousdistances from the edge of Lake Cowal closest to activities during the operation phase. The results ofthis analysis are presented in Table 10.Table 10L Amax Noise Levels across Lake Cowal - OperationProject PhaseDistance From Lake Edge Closest to Operations/L Amax Noise Level (1.5 m/s wind) - dBA1.5 km 2 km 4 km 5.5 km 6 km 7 km 10 kmMining (Year 3) 45 38 31 27 26 23 22Mining (Year 8) 44 37 32 28 27 23 22After: Richard Heggie Associates, 1997Birds tend to habituate to constant steady noise levels, even of a relatively high level in the order of70 dBA (Richard Heggie Associates, 1997). Table 10 indicates that the maximum noise levels underadverse weather conditions at the closest monitored area at Lake Cowal will be 45 dBA during Year 3and 44 dBA in Year 8 (Richard Heggie Associates, 1997). This is below the level of 70 dBA, abovewhich some degree of environmental changes in birds have been observed (Richard HeggieAssociates, 1997). Monitoring of potential operation noise impacts on bird breeding is discussed inSection 8.HAL-02-07/1/NMP01-P/17/11/04 15 BARRICK