By Martin Wurt, President of MTAG
Twenty years is a long time for a little residents’ group to maintain a David and Goliath battle with a state government over trucks. This November marks two decades since MTAG incorporated and started an advocacy campaign that we naively thought would take just a few years to get trucks off our streets. It was, after all, one of Melbourne’s most enduring examples of environmental injustice.
Fast forward to 2025 and this is the biggest year in our history, not just for our anniversary but also the year the West Gate Tunnel finally opens. This project comes with truck bans on most streets in the inner west, streets that have been used as freight routes to service the Port of Melbourne. This shifting of trucks into the tunnel will be a welcome move for so many people who have endured trucks rumbling past their homes for the past decades. (Unless you live on Williamstown Road which is not only not getting a ban but gaining an extra 2,000 daily trucks. see the recent Westsider story)
What is not welcome, as I have written in previous Westsider stories, is unfiltered tunnel exhaust stacks. The Government’s 2017 Inquiry and Advisory Committee recommended filtration from day one. The Government chose to ignore this after the EPA said filtration was not necessary. For years, we have been assured by the Government and EPA that the tunnel vent stacks pose no risk for residents.
Earlier this year, MTAG decided to put this claim to the test. With amazing financial support from the community, we commissioned Synergetics consulting engineers to investigate. Synergetics is among Australia’s leading companies that utilise Computational Fluid Dynamics to understand how pollution will flow.
We posed two questions to Synergetics:
- Does the WGT exhaust stack design represent best practice?
- Are exhaust filters necessary to protect community health?
The report we received back left us speechless!
The as-built WGT ventilation exhaust design was found to have an unusual and complex geometry that does not comply with Good Engineering Practice guidelines for exhaust design resulting in the downwash of the plume.
The exhaust stack does not have sufficient vertical clearance above the surrounding architectural façade and does not satisfy Good Engineering Practice guideline of greater than 2.5 times the height of nearby structures to prevent downwash.
The very low discharge velocity of 6 metres per second from the WGT exhausts will result in the exhaust plume being downwashed for most wind directions.
In essence, the fancy architectural façade on the exhaust stacks will, under certain wind conditions, cause a negative air pressure on the opposite side, dragging pollution down to ground level. The report also found that the speed of the exhaust fan in the stacks is not strong enough to discharge the pollution high into the atmosphere. When you consider the nearest houses to the stacks are just 150 metres away, this is disastrous for our community.
After receiving the draft report in early May we asked local MPs Melissa Horne and Katie Hall for an urgent meeting to discuss its findings. We didn’t want to go to the media without offering the Government the opportunity to consider the report and respond. We were not granted a meeting but instead, through the help of those MPs, met the Minister for Environment Steve Dimopoulos in July to request a Conference of Interested persons that would consider this new evidence.
We discussed the report with the Minister, who expressed confidence in the 2017 Inquiry process and the EPA. His position was, if monitoring proves pollution is too high, the Government will look at this again. He did, however, take action to add more air monitoring near the stacks at our request.
We believe this new evidence is crucial to the EPA’s consideration of Transurban’s application for an operating licence for the vent stacks. That application is currently before the EPA and the tunnel cannot open without the licence.
With the assistance of our lawyers, MTAG has made an urgent submission to the EPA that includes both the Synergetics report and a new health report that examines the latest medical knowledge on the human health impacts of vehicle pollution.
The Victorian Environment Act, amended in 2021, is designed as a preventative model, one that stops pollution before it becomes a problem. We want a condition placed on Transurban’s licence that filtration be fitted as soon as feasible. This would achieve the Act’s vision of empowering communities to stop pollution before it impacts our health, a true preventive approach.
Time will tell if the Government, and the EPA, achieve the Act’s real vision.
