November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

Cowal Gold Project – Noise Management PlanTable 1Construction - L A10(15 minute) Noise Criteriafor the Cowal Gold ProjectDay (7am to 10pm)*Intrusive CriteriaL A10(15 minute) dB(A)Night (10pm to 7am)*35 33* including Sundays and Public HolidaysIn accordance with Consent Condition 6.4(a) these criteria apply under prevailing meteorologicalconditions except during:• rain; and/or• wind speeds greater than 3 m/s; and/or• temperature inversions.Further to this, the CEPL issued by the DEC on 23 December 2003 stipulates that the constructionnoise criteria also applies under temperature inversion conditions of up to 3 o C/100 m and windspeeds up to 2 m/s at 10 m above the ground 1 . The measurement of meteorological conditions at theProject is discussed in Sections 6.1 and 7.2.3.3.2 OPERATIONS NOISE CRITERIAFor the purposes of this NMP and in accordance with DEC requirements (i.e. in accordance withChapter 171 of the ENCM [EPA, 1994] which applies construction site noise level restrictions forperiods not exceeding 26 weeks), “Operational Noise” is defined as Project noise emitted after the first26 weeks of Project works. “Operational Noise” will therefore be emitted during the period whichremains of the Project construction phase after 26 weeks and all Project operations.Operations noise criteria have been derived through a review of background noise and meteorologicalenvironments in accordance with the INP by Richard Heggie Associates (2004). The operationsnoise criteria derived below are consistent with the INP. The DEC has advised that these are therelevant criteria for Project operations, including construction activity after the first 26 weeks of Projectworks 1,2 .A review of the background noise data (Section 4) indicated that a minimum Rating Background Level(RBL) of 30 dB(A) is representative of pre-Project noise environment during the daytime, evening andnight-time periods particularly during the cold seasons. This is consistent with the INP which states:“Where the rating background level is found to be less than 30 dB(A), then it is set to 30 dB(A).”The INP introduces the use of energy equivalent (L Aeq ) descriptor for assessing and controllingintrusive (L Aeq(15 minute) ) and amenity (L Aeq(period) ) noise levels. The LAeq is the equivalent continuoussound pressure level equal in energy to the fluctuating level over a defined interval. The use of LAeqensures greater mathematical rigour and improved noise modelling precision beyond that availablewith statistical noise exceedance levels (L AN ). The L AN statistical noise exceedance values are thelevels exceeded for N% of an interval (e.g. 15 minutes). The L A10(15 minute) is the level exceeded for10% of the time (ie. 90 seconds in 15 minutes) and is often referred to as the average maximumnoise level. The L A90(15 minute) is the level exceeded for 90% of the time and is often referred to as theaverage minimum noise level.12DEC has advised that in accordance with the ENCM, construction noise criteria are applicable under the CEPL for the first26 weeks after the commencement of construction (i.e. until the week commencing 12 July 2004). DEC requires theOperational Noise Criteria to be adhered to after that time.DEC agreed at a meeting on 8 July 2004.HAL-02-07/1/NMP01-P/17/11/04 7 BARRICK