Noise, vibrations and air quality during construction

Noise during construction

How noise is measured

Sound intensity is measured in decibels or adjusted decibels (dB or dBA). This is a logarithmic scale. For example, an increase of 3 dBA is only slightly perceptible to the human ear, while an increase of 10 dBA is perceived as twice the initial noise level.


0 dBA	40 dBA	60 dBA	80 dBA	140 dBA
Threshold of audible sound	Quiet room	Normal conversation	Conversation is difficult; very loud	Intolerable sound level (e.g. jet take-off at < 30 m)

Known sounds in our environment and dBA levels

How is the impact of sound during construction measured?

During the construction phase, some work may generate noise. NouvLR, the consortium in charge of building the REM, is required to comply with noise management requirements.

Here are the noise thresholds to comply with, based on the type of work done:

Fixed site work (construction of stations and related infrastructure)

Daytime (7 am to 7 pm) Average over a 12-hour period	Evening (7 p.m. to 10 p.m.) Average over a 1 hour period	Night (10 pm to 7 am) Average over a 1 hour period
55 dBA or pre-work ambient noise	55 dBA or pre-work ambient noise	45 dBA or pre-work ambient noise

Linear works (construction of railway and road axes)

Noise criteria (in dBA)
Zone and land use	Day (7 a.m. to 7 p.m.)	Evening (7 p.m. to 11 p.m.)	Night (11 p.m. to 7 a.m.)
Criterion (L10, 30 min, dBA)	Maximum peak (LAFmax)	Criterion (L10, 30 min, dBA)	Maximum peak (LAFmax)	Criterion (L10, 30 min, dBA)	Maximum peak (LAFmax)
Noise sensitive zones	75 or ambient noise +5	85 or 90 pour un bruit d'impact	Ambient noise + 5	85	Ambient noise + 5 (if ambient noise smaller than 70) or Ambient noise + 3 (if ambient noise greater than 70)	80
Commercial zones	80 or ambient noise + 5	None	Ambient noise + 5	None	None	None
Industrial zone	85 or ambient noise + 5	None	None	None	None	None

Mitigation measures

The REM project office and NouvLR are implementing measures to minimize noise during the work. These measures are adjusted continuously based on the work done and the sectors. Here are some examples:

Using silencers on equipment
Using temporary acoustic barriers
Continuously raising workers’ awareness
Noise monitoring and follow-up program, including a team of dedicated supervisors
A rigorous complaint management procedure

Want to find out more about noise?

Fact sheet on noise during construction

For more information about noise levels during the REM’s construction, consult the fact sheet.

Consult the fact sheet

Air quality during construction

How is the impact of air quality during construction measured?

The work is subject to standards regarding total particles and fine particles (PM2.5) set forth in the Clean Air Regulation. The standards are 120 µg/m3 over 24 hours for total particles, and 30 µg/m3 over 24 hours for fine particles.

Mitigation measures

Mitigation measures are planned to limit the spread of dust, including:

Using a dust suppressant
Cleaning up public roads
Using tarps on dump trucks and material piles

Vibrations during construction

During the construction phase, some work may generate vibrations, primarily:

Controlled blasting operations
Heavy machinery traffic
Pile driving or installation of piers

NouvLR, the consortium in charge of building the REM, is required to comply with vibration thresholds. These thresholds aim to ensure the integrity of the surrounding structures.

Mitigation measures

Before beginning the work, NouvLR identifies the buildings and infrastructure in the construction zone. Inspections are done and work methods are selected to minimize the transmission of vibrations to the ground.

In sensitive areas, measurements will also be done before construction work begins, so as to determine the level of ambient vibration.

Tight control of vibrations is ensured during the work, which means:

Using seismographs positioned at the borders of the construction zone
Analyzing results in real time and immediately adjusting work methods as required