The Age • Patrick Hatch • June 25, 2022 — 7.00pm
Louder and more frequent aircraft noise from Melbourne Airport’s proposed third runway could affect a larger number of western suburbs residents than previously forecast, an acoustics expert has warned.
Melbourne Airport, which says it needs a new $1.9 billion, three-kilometre runway by 2030 to cope with passenger numbers predicted to double to 83 million a year by 2046, expects to submit final plans to the Federal Infrastructure Minister Catherine King later this year.
Plans to shift most flights from the existing east-west runway onto the proposed second parallel north-south runway has alarmed residents in nearby suburbs including Bulla, Keilor and Kealba, while noise would also spread further south over Sunshine, Braybrook, West Footscray and as far as Williamstown.
Dr Eric Ancich, an engineer with 30 years professional experience in acoustics, said in a submission to the runway’s public consultation process that noise could be even worse than residents had been told.
“Noise modelling is not reality, it’s an approximation of reality. Unfortunately, it’s presented as reality, but it’s not what it will be,” he said in an interview. “It’s unlikely to be less than that, and it’s almost certainly going to be more than that.”
The airport uses “number above” maps to show how many times a day aircraft noise on the ground will exceed 60 decibels (the volume of a normal conversation, which could wake someone sleeping inside) or 70 decibels (similar to a lawn mower or vacuum cleaner). Some residents are set to experience such volumes 200 or more times a day.
Ancich said parts of Melbourne not forecast to experience loud or frequent noise could do so, because the maps were based on assumptions about widely varying factors including weather conditions, flight paths and jet altitude.
Melbourne Airport had been upfront with the public and had tried to present the most accurate forecast possible of the noise impact, a spokesman said.
“Naturally, there are limitations in the forecasting given currently available information and technology, but the [number above] maps provide the community of a close approximation of what they can expect when the runway opens,” he said.
“Melbourne Airport has been upfront about the forecast impacts associated with the new runway, and has received positive feedback from members of the public on the transparency and respect shown by airport of staff on issues related to aircraft noise.”
Ancich’s report, commissioned by the Melbourne Airport Community Action Group, is based on research he conducted that challenged noise maps for the new Western Sydney Airport.
By measuring noise under flight paths at a set distance from the existing Sydney Airport, the research showed planes from the new airport would inflict noise of 70 decibels or more on the City of Blacktown, almost 20 kilometres away, despite noise maps showing it would be unaffected.
Bulla resident Theresa Micallef said she feared noise in the home her husband Victor built for the couple 33 years ago would become unbearable if planes start taking off from the proposed runway, about two kilometres away.
“It’s going to disturb our sleep, it’s going to disturb our way of living. If you want to hear the TV, turn it right up; if you want to have a discussion inside, you have to speak fairly loud,” she said.
“I feel scared, because we don’t want to shift. We can’t see ourselves living anywhere else.”
If the runway does go ahead, Micallef said there should be a curfew like at Sydney Airport so residents could at least sleep, and that the airport or state government should pay for noise insulation.
A report by environmental and engineering consultancy Tonkin & Taylor for Brimbank Council, which takes in suburbs south of Melbourne Airport, has also found the noise maps may understate the true effect of the runway.
Aircraft noise at 70 and 80 decibels had previously been recorded at homes in Kealba and Keilor Village, despite the airport’s online noise map tool showing they should not experience noise that loud.
“This has raised concerns about the accuracy of future predictions of noise when the current experience at their homes is that they are impacted more severely than the noise tool is predicting,” Dr Lyn Denison wrote.
Airservices Australia, which manages flight paths, also conceded to Senate estimates last year that there would “always be a difference between the theoretical [noise] modelling and measured results”.
Melbourne Airport had planned to build a third runway running east-west, but in 2019 it switched to a north-south plan to avoid wind interference. It has long-term plans to build a fourth runway running east-west.
Brisbane Airport has been forced to trial modified flight paths following an outcry from nearby residents complaining of noise, sleep disruption and mental distress since it opened its new runway in 2020.
An Aircraft Noise Ombudsman report found in October last year that more flights at 70 decibels or above were landing or taking off at the airport than the airport’s 2018 noise footprint showed.