By Saturday, September 13, 2014 0 No tags Permalink 1


On September 11, the Star published an online story about the port authority’s web tracking service for aircraft in and around the island airport.  The Star’s story followed much of what the port authority deemed newsworthy in its own media release.


The article quotes Gene Cabral, the airport’s executive VP, as saying, “We want to give full transparency to our neighbours.”  He also claimed that noise mitigation is the airport’s priority.


Earlier this year Mr. Cabral made another interesting claim when he wrote to Christopher Dunn, Project Manager – Waterfront Secretariat.  He stated, “The City Board of Health completed a comprehensive study of this issue and determined that the BBTCA is not a significant contributor to air pollution in the City’s waterfront community.”


Mr. Cabral wrote this after the Toronto Board of Health voted unanimously to reject airport expansion.  The Board followed recommendations from Dr. David McKeown, the Medical Officer of Health, whose report cited the airport as the likely producer of nine different carcinogens “predicted to increase the lifetime cancer risk at locations near the airport” and being responsible for 10 to 15 per cent of all the air pollution in the surrounding area.


With regard to Mr. Cabral’s claim to transparency, the current WebTrak set up, as it is available to the public, could allow the port authority to argue that there is no noise problem.  Perhaps that’s because the noise levels are recorded by receptors nowhere near the problem areas as Max Moore knows them.   To add confusion, airport generated noise is reported using a measurement that mitigates the sound levels.  Could this be what Mr. Cabral refers to as mitigating noise levels as a priority?


The following screen capture (Fig. 1) shows the two receptor locations: one between Lower Simcoe and Lower Spadina (circle 58); the other near the island firehall (circle 46), well away from the harbour flight path and the airport.  There are no receptors adjacent to the community or school just north of the airport, where Max Moore and others have been expressing anguish over the effects of the airport noise.

Receptor locations

Fig. 1 – WebTrak Location Receptors

While the location of the receptors can’t hope to capture the full airport noise impact on the closest community and the nearby school,  the port authority’s WebTrak application shows the receptors measuring the leq, the Equivalent Sound Level.  This is a measurement used where sound levels vary over time.  Leq assesses the impact of cumulative noise exposure.   As the city’s consultant AIRBIZ puts it, “Cumulative aircraft noise contours often are challenged by airport neighbors as not representing what can be heard and measured every time an aircraft ies near their home. Long duration measurements and computer technology may indicate the contour patterns are appropriate for community planning, but they fail to capture the discrete nature of the single events that people actually identify and complain about.”
The screen capture below (Fig. 2) shows the leq readings for the two locations YTZ1 on the island and YTZ2 between Lower Simcoe and Lower Spadina.  The readings display acceptable cumulative readings for the two locations.  Readers may see for themselves on the WebTrak site that when an aircraft lands at or takes off from the island airport, the values are still in the acceptable range or are little changed even though the aircraft ay be right over the receptors – such is the problem of cumulative noise measurement.

Leq proof

Fig. 2 – Leq Readings

The AIRBIZ document reports on solutions to the problem: ways to measure single noise events.  A history of single noise event measurements that show decibel level well beyond the acceptable range could be a powerful tool in a case against airport-generated noise.  Effective Perceived Noise Level (EPNdB) is one such measurement.  EPNdB takes into account annoyance, intensity, tonal content and duration of a single aircraft’s noise. EPNdB is used by International Civil Aviation Organization and Transport Canada to certify noise levels of aircraft and create their noise profiles.


EDNdB is also the measure cited in the Tripartite Agreement, to which the port authority and Transport Canada are signatories, and is used to determine the noise profile limits of aircraft using the island airport.  However, the port authority’s WebTrak application does not have the capacity to measure and report individual aircraft noise or if it does it does not allow the public to access it. Interestingly, WebTrak does have an application, MyNeighbourhood, which measures instances of noise events above 70 decibels.


Why has the port authority located the WebTrak receptors so far away from the community most affected by airport-generated noise?


Why wouldn’t the port authority, which professes transparency, choose not to make single noise event information available to the public?


Is the port authority’s use of WebTrak is just another public relations exercise?

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