Noise and Vibration

There are several factors we will consider in assessing noise during construction. This includes identifying sensitive receptors. Sensitive receptors are areas that are considered to be sensitive to noise, including residential dwellings, schools, daycare facilities, hospitals, seniors’ residences, and places of worship. Commercial and industrial buildings are typically not considered sensitive receptors relative to noise.

We will consider the existing noise environment, the noise levels during construction activities and the adjacent land use. We will also assess the potential noise effects from haul roads for construction-related trucks, based on projected haul traffic counts, including dump truck and delivery truck movements and excavation haul traffic volumes.

We want to be proactive in mitigating noise from the construction project where required. That is why we are assessing several factors that will allow us to determine what, if any, mitigation will be required during construction and for how long it will be needed. These factors include:

• Frequency of the noise event – How often does the noise occur?
• Duration of the noise event – How long does it last?
• Perception of the noise by the receiver – As some people are more sensitive to sound than others, we will consider how loud the noise is perceived to be
• Sound frequency – A low frequency sound is perceived differently than a high frequency sound, so we will consider the pitch of the noise

We will take several actions in an effort to mitigate noise during construction of this project. Metrolinx will provide a detailed impact assessment and comply with the Ministry of Environment operating standards. All construction equipment on site will be operated in accordance with Ministry of the Environment publication NPC-115.

We will use vehicles and equipment with efficient muffling devices and employ alternative equipment that generates less noise where possible. This includes avoiding impact pile driving where possible. We will install rubber linings in equipment such as chutes and dumpers to reduce impact noise.

Vehicles that are used for extended periods of time (two days or more) will be fitted with sound reducing back up (reversing) alarms, while adhering to construction safety standards. We will also supply electrical power directly from the grid where possible to avoid continuous use of generators.

In addition to these mitigation measures, specific areas along the corridor may require supplementary mitigation, depending on the noise generated and duration of construction activities. In these cases, supplementary mitigation that may be implemented includes:

• Conducting noise compliance checks to ensure equipment levels respect City of Toronto by-laws and Ministry of Environment (MOE) Standards, including NPC-115;
• Re-routing construction and truck traffic;
• Coordinating noisy operations so that multiple noise-generating equipment is not running simultaneously where possible;
• Investigating and implementing the use of alternative construction equipment or methods to reduce noise emissions from construction where possible and economically feasible; and
• Installing acoustic enclosures, noise shrouds or noise curtains around noisy equipment where necessary and feasible.

Metrolinx is working directly with independent third parties to regularly monitor construction noise along the corridor.

During construction, we will conduct noise monitoring at locations that are representative of the nearest sensitive receptors.

To monitor the levels, we will take into account the existing noise environment, the absolute noise levels during construction activities, the duration of the construction and the adjacent land use.

If levels are determined to be above typical noise levels for construction activity, and have a long duration, the noise monitoring reports will be reviewed and, if necessary, additional measurements will be done at the location of concern to determine if further mitigation is needed.

Where construction work unrelated to this project is underway in the same area, there is a chance increased noise and vibration generated by other construction activities outside the Georgetown South Project may impact noise and vibration levels in the community. In such cases, the owners of those unrelated projects are responsible for managing the noise and vibration resulting from construction on their sites.

During construction, we will assess vibration with respect to human perceptibility and potential building damage. We will measure the baseline vibration levels to benchmark current vibration levels, so we can compare levels during construction with the baseline to determine the level generated by our construction.

We will investigate impacts where in-ground vibration levels are 5 mm/s (millimeters per second) or more.

We will undertake several measures to mitigate vibration during construction of the project. This includes:

• Operating in accordance with local by-laws whenever possible;
• Considering the use of alternative construction methods to minimize vibration;
• Using lower vibration-generating equipment where practical; and
• Avoiding impact pile driving where possible and technically feasible.

In addition to these measures, specific areas along the corridor may require supplementary mitigation, depending on the vibration generated and the duration of construction activities. This includes:

• Adjusting energy input/speed of processes;
• Imposing operational time restrictions on construction equipment;
• Investigating and implementing the use of alternative construction equipment or methods to reduce vibrations from construction, where practical; and
• Utilizing alternative equipment that generates lower vibration levels, where practical.

Metrolinx will work directly with independent third parties to regularly monitor construction vibration along the rail corridor. We will conduct vibration monitoring at locations representative of the nearest sensitive locations.

In the event that the vibration measurements are beyond regular construction levels and have a long duration, the reports will be reviewed and, if necessary, additional measurements will be done at the location of concern to determine if further mitigation is needed.

Where construction work unrelated to this project is underway in the same area, there is a chance increased noise and vibration generated by other construction activities outside the GTS Project may impact noise and vibration levels in the community. In such cases, the owners of those unrelated projects are responsible for managing the noise and vibration resulting from construction on their sites.