Air Quality Monitoring Stations - Monthly Results

As part of the Environmental Assessment for the Samuel De Champlain Bridge corridor project, which included consultations with local residents, Infrastructure Canada committed to monitoring and reporting on air quality during the construction of the bridge. The air quality monitoring program is for particle pollution as this was determined to be the main area of concern based on the planned construction activities.


Air quality sampling station on Île-des-Soeurs

Monthly Results

As of April 1st 2017, based on Environment and Climate Change Canada recommendations, only concentrations of Total Particulate Matter (PMtot) and Particulate Matter with a diameter of 2.5µm or less (PM2.5) will be monitored at both the île des Soeurs and Brossard air quality monitoring stations.





How do I read the monthly results?

The monthly results provide the concentration of each monitored pollutant in the air, for every day of the month, for the intervals at which they are recorded.

All pollutants are measured continuously, but reported using multiple time intervals, dependant on the pollutant. Any time the concentration of a pollutant in the air exceeds the stated threshold (acceptable maximum concentration), it is marked with an asterix (*).

In the excerpt below from the January 2016 report for Île-des-Sœurs, you can see that on January 8, the threshold for fine particulate matter was exceeded for a 3 hour period by 4 micrograms per cubic metre.

Sample table description to explain Air Quality Monitoring Stations - Monthly Results

What happens when an air quality threshold is exceeded?

The private partner, Signature on the St. Lawrence Group, is informed immediately when an air particle threshold is exceeded and they have 60 minutes from the time they are advised to address the source of the pollution. Depending on the situation, this could involve immediately stopping the activity causing the pollution or using water or another approved substance to reduce the amount of particles in the air. If the situation is not adequately addressed, the private partner is subject to a financial penalty. The amount of the penalty depends on the length of time the threshold is exceeded as set out in the Project Agreement.

Where is this monitoring happening?

An air monitoring station has been installed on the Île des Sœurs to collect air quality data during the construction of the bridge and for a period following the opening of the new corridor to traffic.  In addition to the Île des Sœurs station, a second air monitoring station is also collecting data from Brossard, beginning in spring 2016.

Why is it needed?

This continuous monitoring is to ensure that the requirements related to air quality set out in the Project Agreement are respected by the private partner, Signature on the St. Lawrence Group (SSL). If air particle pollution exceeds allowable limits an alert is sent to SSL who is required to take immediate action to identify the source of the pollution, and address it using appropriate mitigation measures, if located on the worksite.

What is Particle Pollution?

Particle pollution (also called particulate matter or PM) is a mixture of solid particles and liquid droplets found in the air. Larger particles from sources such as dust, dirt or smoke may be visible while particles from other chemical sources are microscopic. See Environment Canada's website for additional information.

How is Particle Pollution measured?

The data gathered by the monitoring stations is measured against specific thresholds based on current municipal and provincial legislation and other references. Measurements are taken constantly and reported over durations of one, three, eight and 24 hours. The concentration of particle pollution in the air is measured in micrograms per cubic metre (µg/m3). One microgram is equivalent to one millionth of a gram.

Additional Air Quality Monitoring

As part of the INFC's commitment to minimizing the project's impact on the overall environment,  the stations also collect data on the level of Criteria Air Contaminants and related pollutants  (also known as gaseous pollutants) in the air which are known to cause air quality issues including smog.

Since these pollutants are not part of  INFC's monitoring program, there is no alert system; however, the data is collected for documentation and follow-up purposes and to provide baseline data to help evaluate the impact of the project (once open to traffic) on overall air quality in the region.

Specific thresholds for these pollutants are based on current municipal and provincial legislation. Measurements are taken constantly and reported over durations of four minutes, one hour, eight hours and 24 hours. The concentration of gaseous pollutants is measured in parts per billion (ppb).

Other Frequently Asked Questions

Other frequently asked questions related to air quality can be found here

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