Warrawee Substation - Review of Environmental Factors

Warrawee Substation Page 32Operational Noise & Construction Noise & Vibration AssessmentReport No. 11332 Version B9 TRAFFIC NOISE FROM CONSTRUCTION TRAFFICThe NSW Office of Environment and Heritage Road Noise Policy (RNP) presents the NSWGovernment’s guidelines for road traffic noise assessment. Whilst not specifically designed todeal with temporary traffic increases during construction, it provides some guidance on likelyimpacts due to increased traffic.In the initial stages and towards the end this development will contribute to a small increase inlocal traffic. Based on the RNP this development would be classified as:‘Land use for development with potential to create additional traffic on local roads’ with thelocal roads referring to Brentwood Ave and Hastings Road.The recommended criterion for situation is:Day (between 7.00am and 10.00pm) – L Aeq,1hr 55dBA.Where criteria are already exceeded, traffic arising from the development should not lead to anincrease in existing noise levels of more than 2dB.The traffic movements relevant to the works will be mainly to transport plant, equipment andmaterials to site with the exception of the ‘Site Demobilisation’ stage where constructionequipment, plant, materials and site offices will be removed from site.There has been two proposed management plans for traffic flow to the site based ondiscussions with the client.Scenario A – traffic will enter the site via Brentwood Ave and leave the site via HastingsRoadScenario B – traffic will enter and exit the site via Brentwood Ave.Scenario AThe traffic flow has been designed such that traffic will enter site via Brentwood Avenue andexit the site via Hastings Road. At this point all deliveries and removal of plant has beenscheduled during the day.Under the worst-case scenario, up to an additional 3 truck movement per hour on BrentwoodAvenue and Hastings Road could be generated by the project. Using the Calculation of RoadTraffic Noise (CoRTN) traffic noise prediction technique, the contribution of these truckmovements has been estimated. Assumptions in this calculation include:vehicle speed 40km/h;distance to façade 9m; and difference of 3dB between CoRTN-calculated L A10,1hr noise levels and L Aeq,1hr .The calculated contribution from three truck movements per hour associated with the project is52dBA L Aeq,1hr. This is 3dBA below the criteria and considered acceptable, particularly since theincrease in traffic flow will be temporary, whereas the above criteria are intended forassessment of a permanent increase in traffic volumes.