Noise Monitoring Terminals (NMTs) Around Toronto Pearson
Toronto Pearson’s operator, the Greater Toronto Airports Authority (GTAA), states that it has been “monitoring noise in neighbouring communities and areas under flight paths since the 1970s” and that there are currently 25 active Noise Monitoring Terminals (NMTs) distributed around the airport. These monitors feed into the Airport Noise and Operations Monitoring System (ANOMS).
Status of information requests
On January 9, 2026, Pearson Accountability Alliance submitted two formal requests for detailed noise-monitor outage logs covering the Toronto Pearson NMT network:
- A joint email request to GTAA and NAV CANADA asking for a complete log of all NMT outages, faults, and maintenance events.
- A formal Access to Information (ATI) request to Transport Canada requesting records related to NMT availability, outages, and configuration changes.
On February 24, 2026, Pearson Accountability Alliance emailed the GTAA Noise Management Office documenting several issues affecting the public monitoring system, including:
- the WebTrak flight-track outage;
- the Pond Street NMT outage; and
- approximately 20 days of invalid fixed readings at the Marvin Heights Public School monitor.
On March 9, 2026, a follow-up email was sent noting that the Pond Street monitor was still offline. No response was received.
Based on community screenshots, the Pond Street monitor appears to have remained offline from the morning of February 18, 2026 until sometime after midday on March 12, 2026 — a downtime of approximately 22 days.
If information is received from GTAA, NAV CANADA, or Transport Canada, this page will be updated to publish the records and provide a detailed timeline of monitor availability.
Evidence documents — January 9 outage-log request, February 24 email, March 9 follow-up
Until detailed outage records are disclosed, the absence of those logs — and the lack of response to documented outage reports — should itself be understood as part of the public record.
GTAA refusal to disclose NMT performance data
On February 9, 2026, the GTAA responded to a request from Pearson Accountability Alliance seeking operational and noise-monitoring information related to Toronto Pearson’s monitoring network.
In its written response, the GTAA stated that information such as general operational datasets, flight activity, NMT performance metrics, and system-level monitoring information would not be disclosed.
The GTAA stated that general operational datasets, flight activity, and NMT performance metrics are “confidential and not subject to release,” that “no additional operational or system level data is available for disclosure,” and that it “will not authorize or participate in any private or unsolicited external audit of operational activities.”
This means the public does not have access to basic performance information for the system used to characterize aircraft noise exposure in surrounding communities.
Because GTAA does not publish monitor uptime statistics, outage logs, or performance metrics, the public has no independent way to verify whether the monitoring network was functioning during the periods used to generate official noise statistics.
Evidence document: GTAA response to request for operational and noise-related information (February 9, 2026)
What the GTAA says about noise monitoring
According to the GTAA, NMTs are used to obtain objective data and assess aircraft noise levels. NMTs are one source of information that feeds into ANOMS, which correlates noise events with aircraft operations to create “Aircraft Noise Events”.
- “25 active Noise Monitoring Terminals (NMTs) in neighbourhoods around the airport.”
- Noise events are measured against a sound level threshold:
- 65 dBA from 06:30 to 23:59
- 60 dBA from 00:00 to 06:29
- Noise events must last at least five seconds to be recorded.
- Recorded noise events are then checked against flight operations to flag “Aircraft Noise Events”.
- Pearson is federally regulated and “not bound to any municipal noise by-laws,” and there is no maximum legal noise limit; instead, the GTAA points to “noise abatement procedures” and “land use planning” as its main tools.
On paper, this sounds like a robust, science-based system. In practice, the reliability and transparency of the underlying network remain open questions.
Noise-monitoring infrastructure around Pearson
The GTAA publishes a map of NMT locations distributed around Pearson. These monitors are presented as a permanent, reliable network that has been operating since the 1970s. However, the GTAA does not publish:
- Uptime / availability statistics for each monitor;
- Historical outage logs (dates, durations, and causes);
- Maintenance or calibration records; or
- Any formal trigger for public notification when a monitor goes offline.
This page documents the infrastructure that exists and the reliability failures that affected communities have been reporting.
Current Noise Monitoring Terminals (NMTs)
The following table lists the NMTs currently published by the GTAA.
| Monitor | Neighbourhood / Site | Primary flight paths monitored |
|---|---|---|
| Acacia Ave. NMT | Acacia Avenue / Acacia Park area | Directly under 24L/06R and 23/05 path |
| West Humber Collegiate Institute NMT | West Humber Collegiate Institute (Etobicoke North) | Arrivals and departures along northern corridors |
| Eriksdale Ave NMT | Eriksdale Avenue (Etobicoke Centre) | Approach and departure tracks for east–west operations |
| Garnetwood Park NMT | Garnetwood Park (Mississauga East) | South/east corridors |
| James S. Bell Public School NMT | James S. Bell Junior Middle School (Etobicoke / Long Branch) | South corridors over the lakeshore communities |
| NAV CANADA Pond Street NMT | NAV CANADA / Pond Street area (Airport Corporate Centre) | Mixed arrivals/departures near the airport campus |
| Dearbourne Park NMT | Dearbourne Park (Brampton South) | Northwest arrival streams |
| Grenoble Public School NMT | Grenoble Public School (Brampton Central) | North–south traffic over Brampton |
| New Life Community Church NMT | New Life Community Church (Mississauga Malton) | Intense operations over Malton residential area |
| Marvin Heights Public School NMT | Marvin Heights Public School (Mississauga Malton) | Night-time arrivals and departures over Malton |
| BraeBen Golf Course NMT | BraeBen Golf Course (Mississauga Heartland) | High-altitude overflights and vectoring |
| South Fletchers Sportsplex NMT | South Fletchers Sportsplex (Brampton West) | West of airport; mixed traffic |
| Peel Village Golf Course NMT | Peel Village Golf Course (Brampton) | East–west paths over Brampton |
| Brampton Fire Station #209 NMT | Brampton Fire Station #209 (Brampton East) | Concentrated corridors over eastern Brampton |
| Meadow Glen Park NMT | Meadow Glen Park (Mississauga Meadowvale) | Northwest flight patterns |
| Richview Ambulance Station NMT | Richview Ambulance Station (Etobicoke Richview) | Major corridor for 24R/06L operations |
| Blackfriar Park NMT | Blackfriar Park (Etobicoke North) | North Etobicoke flight paths |
Selected 2026 monitoring system issues
| Date | System / Monitor | Observed issue | Status based on available evidence |
|---|---|---|---|
| Jan 2026 (~20 days) | Marvin Heights Public School NMT | Readings appear locked between roughly 60–80 dB | Apparent monitor malfunction producing invalid data |
| 18 Feb 2026 | Pond Street NMT | Monitor appears offline before noon | Beginning of documented outage period |
| 24 Feb 2026 | WebTrak | Flight-track data outage acknowledged by GTAA | Public notice posted stating outage began Feb 24 at ~7:30 AM |
| 24 Feb 2026 | PAA → GTAA | Email sent documenting multiple monitoring issues | No reply received |
| 9 Mar 2026 | PAA → GTAA | Follow-up email noting Pond Street still offline | No reply received |
| 12 Mar 2026 | Pond Street NMT | Monitor appears to return to service | Approximate outage length: 22 days |
Monitor-specific evidence summaries
NAV CANADA Pond Street NMT – February–March 2026 outage
The Pond Street Noise Monitoring Terminal appears to have been offline from the morning of February 18, 2026 until sometime after midday on March 12, 2026, for a total outage of approximately 22 days.
Community screenshots captured on February 18, February 19, February 24, and March 9 show the monitor absent or non-reporting while other monitors remained visible on the GTAA WebTrak / noise-monitoring map. Despite the duration of the outage, no public explanation or outage notice was observed during this period.
On February 24, 2026, Pearson Accountability Alliance emailed GTAA requesting clarification about the Pond Street outage, the WebTrak outage, and invalid fixed readings at Marvin Heights Public School. No response was received. On March 9, 2026, a follow-up email was sent specifically noting that Pond Street was still offline. Again, no response was received.
A monitor that remains offline for approximately 22 days without clear public notice undermines the credibility of Pearson’s noise-monitoring network as a transparency tool. Communities cannot reasonably be expected to rely on a system that provides no systematic public disclosure when key monitors fail.
- February 24, 2026 email to GTAA re: WebTrak outage, Pond Street outage, and Marvin Heights fixed readings
- March 9, 2026 follow-up email to GTAA re: Pond Street still offline
Acacia Avenue / Acacia Park NMT – Evidence Summary
- Emails documenting outages beginning in 2023 and continuing in subsequent years.
- Known long-duration outage of approximately three months in 2023.
- Additional periods where local residents report the monitor as “flat-lined” while aircraft were clearly audible overhead at night.
- Repeated community attempts to obtain explanations and outage logs, with no detailed public accounting of downtime or reconstructed data.
Published Acacia Park noise data – 2025 (Pearson Accountability Alliance)
How Pearson’s NMTs count “noise events”
On the GTAA’s own description, a noise event at an NMT is only captured when two conditions are met:
- The sound level exceeds a threshold (65 dBA by day, 60 dBA at night); and
- The sound level stays above that threshold for at least five seconds.
If either condition is not met — for example, a very loud but brief overflight, or repeated peaks just below the threshold — the event may be invisible in GTAA’s statistics, even if residents experience it as highly disruptive in their bedrooms at night.
GTAA’s own 45 dB harm threshold
In its official Restricted Hours Operating Policy (Version 4.1, May 29, 2019), the GTAA states that, during the restricted hours, it works with NAV CANADA to maintain flight procedures that “minimize the number of community residents that are overflown at a decibel rating above 45 dB”. In other words, GTAA itself treats 45 dB as the level beyond which nighttime aircraft noise exposure must be minimized for residents.
Yet in neighbourhoods such as Acacia Park, independently compiled data from the Acacia noise monitor show repeated nighttime events between 75 and 80 dB, and sometimes higher. On a logarithmic scale, an 80 dB event is perceived as more than 10 times louder than a 45 dB event.
How GTAA uses NMT data to compare “aircraft” vs “community” noise
In addition to WebTrak and ANOMS, GTAA publishes interactive dashboards that claim to show how aircraft noise compares to “community” or “ambient” noise.
On these dashboards, the bars for “community” noise are often shown as equal to or higher than the bars for “aircraft” noise. These comparisons rely entirely on the integrity of the NMT monitoring network.
When monitors are stuck, degraded, or offline, those comparisons become difficult to verify independently. This is especially significant because the same operator that controls the aircraft operations also controls the monitoring network, the thresholds, and the dashboards used to present the results.
Unexplained halt in GTAA noise reporting
The GTAA publishes quarterly “Aircraft vs Community Noise” reports through its public noise-reporting portal. As of March 2026, the most recent data visible on that dashboard appears to be from Quarter 4 of 2024.
No reports for 2025 or 2026 appear to have been published on the public portal.
As documented elsewhere on this page, the public monitoring system has shown signs of unreliability, including a ~22-day outage of the Pond Street NMT, a ~20-day period of fixed readings at the Marvin Heights monitor, and a WebTrak flight-track outage acknowledged by GTAA.
Despite these issues, GTAA does not publish NMT uptime statistics, outage logs, or performance metrics.
It is therefore unclear why the quarterly reports appear to have stopped after 2024, or whether the gap is related to technical, operational, or reporting changes within the monitoring system.
Examples: WebTrak views – Marvin Heights Public School monitor
The screenshots below show WebTrak views captured between December 29, 2025 and January 10, 2026. They are part of a community-maintained record of Marvin Heights Public School NMT behaviour that extends from 2023 onward.
- Locked at abnormally high values, starting around 65 dB and ratcheting upward day after day into the high 70s, even when aircraft were distant;
- Not reacting to runway changes or traffic load, unlike neighbouring monitors;
- Staying at these inflated “background” levels for roughly three weeks, with no return to realistic community readings during the period observed; and
- No public notices from GTAA or NAV CANADA about the malfunction or data-quality issue.
This behaviour is consistent with a malfunctioning or stuck monitor — a serious issue for a system used to justify GTAA’s “community vs aircraft noise” comparisons.
Supporting documents for this section
- GTAA Restricted Hours Operating Policy v4.1.1 (PDF) — GTAA policy that acknowledges the need to minimize residents’ exposure above 45 dB at night.
- Sanitized 45 dB notification letter (PDF)
- ATI request to Transport Canada – NMT outage and reliability records (PDF)
- Joint NAV CANADA / GTAA request – NMT uptime and outage logs (PDF)
- GTAA response refusing disclosure of NMT performance metrics and system-level data (PDF)
- February 24, 2026 email to GTAA regarding WebTrak and NMT issues (PDF)
- March 9, 2026 follow-up email to GTAA regarding Pond Street still offline (PDF)
Why NMT uptime matters for health and accountability
When monitors are offline, every missed night becomes a blank in the official record. Yet the aircraft still fly, and the noise still enters people’s homes.
When monitors are down, the harm is still real — but the data disappears. This systematically advantages the airport operator and disadvantages the residents, workers, and public-health systems that bear the cost.
Take Action: Demand an Independent Audit
The noise monitoring system is opaque, self-administered, and not independently verifiable by the public. Residents can use this page to email the Minister of Transport, copy their MP, and also notify their municipal council and local Board of Health.
Step 1: Turn this evidence into a formal record
Use the form below to generate a letter you can adapt for MPs, councils, Boards of Health, or media. You can copy the text or open it directly in your email program.
Turn This Evidence Into a Formal Record
Generate a formal letter you can adapt for MPs, councillors, ombuds, unions, or media.
Step 2: Where to send this evidence
Use the tools below to send this evidence to federal, provincial, municipal and public-health decision-makers.
Knowledge Is Power — Join the Alliance
When institutions control the information, communities lose their voice. By joining the Pearson Accountability Alliance, you gain access to facts, evidence, and tools that help you and your neighbours push for real accountability.
Evidence documents cited on this page
- GTAA Restricted Hours Operating Policy v4.1.1 (PDF)
- Sanitized GTAA 45 dB letter (PDF)
- ATI request to Transport Canada re: NMT outage and reliability records (PDF)
- Joint NAV CANADA / GTAA NMT failures correspondence (PDF)
- GTAA response refusing disclosure of NMT performance metrics and system-level data (PDF)
- February 24, 2026 email to GTAA regarding WebTrak and NMT issues (PDF)
- March 9, 2026 follow-up email to GTAA regarding Pond Street still offline (PDF)
For regulators, investigators, and auditors
A structured archive of noise-monitor outage emails, screenshots, dashboard gaps, and ANOMS/WebTrak discrepancies is available on request.
Please contact info@pearsonaccountabilityalliance.org for access to the full evidentiary package.
PAA’s position
Pearson operates on federal land under a Ground Lease with Transport Canada. After years of unresolved NMT failures, missing outage logs, refusal to disclose performance metrics, and gaps in public reporting, it is no longer credible for the federal landlord to look away.
Pearson Accountability Alliance
Independent Environmental & Public Health Research for Toronto Pearson Communities.