The Acoustic Assessment Report (AAR) forms an integral part of the Environmental Compliance Approval application for facilities or operations that are located in close proximity to sensitive receptors such as houses, apartments, schools, hospitals, day cares, and places of worship. Ontario’s Noise Pollution Control Guideline (NPC-300) specifies the allowable noise limits for sensitive spaces.
It defines four classes of land, and the applicable noise limits for each.
Class 1 area – major urban centre, where background sound level is dominated by people and road traffic (i.e. City)
Class 2 area – between Class 1 and Class 3, which has sound levels similar to Class 1 during the day, but similar to Class 3 during evening and nighttime
Class 3 area – rural area where background sound level is dominated by natural sounds having little or no road traffic (i.e. small communities, agricultural area, cottage or resort area, wilderness)
Class 4 area – Class 1 or 2 area, that is intended for development with new noise sensitive land uses that are not yet built, is in proximity to existing stationary noise sources, and has formal confirmation from the land use planning authority with the Class 4 Designation
In building the Acoustic Assessment Report, noise data is collected by onsite measures of the noise-generating equipment, collected from manufacturers data and, where necessary, background noise data from the surrounding area can also be collected from long-term noise monitors. These sound power levels are used to create an acoustic model of the facility to predict the impact at sensitive receptors. If compliance can be demonstrated, then the ECA application can be submitted. If the predicted sound levels are above the guideline, the facility must create a Noise Abatement Action Plan (NAAP). The Noise Abatement Action Plan establishes which control and mitigation measures will be installed by the facility, such as installation of silencers, barriers, etc. that will be required for the facility to demonstrate compliance, as well as the timeline for their implementation. The NAAP will need to be submitted along with the Acoustic Assessment Report for an Environmental Compliance Approval to be granted.