Victoria’s chief environmental scientist has said he is comfortable not having air filters in ventilation stacks for the West Gate Tunnel, but has left open the possibility they could be added in the future.
Professor Mark Taylor from the Environmental Protection Authority Victoria (EPA), said the 2017 decision to not recommend filters was made after modelling showed vehicle emissions from the tunnel’s two ventilation stacks would have little effect on ground level air quality.
“The (EPA) team did a risk assessment and it showed very clearly that impacts were not significant,” Professor Taylor said.
“I’m comfortable on the basis of what I’ve seen, but I’m also comforted that there will be an opportunity to revisit that question because there will be two independent risk assessments done on the real data during operation.”
Six testing stations will monitor air quality near the stacks once the tunnel opens late this year or early next.
Professor Taylor said any retrofitting of filters would depend on the data, but that the results of earlier modelling meant installing them during construction couldn’t be justified.
“We couldn’t ask the proponent to put in ventilation at the time because it wasn’t proportionate to the risk.”
Professor Taylor spoke to Star Weekly at a public forum in Brooklyn on April 2, where EPA staff discussed their decision not to install filters with local residents.
A campaign to have the decision reversed has gained momentum as the ventilation stacks, and the tunnel itself, near completion.
“We’re here to listen to the community, listen to their concerns and provide further explanation on the scientific rationale behind the decision,” said Professor Taylor of the forum which attracted 70 people.
Instead of filters, high velocity fans will blow emissions out of the stacks at a height where it will not damage air quality on the ground.
However, the stacks do have room for filters to be retrofitted if required, something Western Metropolitan MP David Ettershank asked the government about in parliament last month.
“Closing the tunnel to retrofit filters on the stacks would be ridiculously expensive,” speculated Mr Ettershank when inquiring about the cost compared to installing filters now.
The Legalise Cannabis Party MP also asked why there were no air monitoring stations near the southern stack and why only one station would test for carbon monoxide and nitrogen dioxide?
Environment Minister Steve Dimopoulos was contacted for comment.
