In the early hours of a February morning, Carly McGregor was called to a large fire at a plastics factory in Keysborough, in Melbourne's outer south-east.
The senior environment protection officer with Victoria's Environment Protection Authority (EPA) was on site within 40 minutes, and immediately began observing the smell, the smoke, and the water running off the site.
"Fire water is always going to have contaminants," she said.
In this case, the factory contained 20 tonnes of nurdles — tiny plastic pellets about the size of a lentil, used to make water bottles.
They were quickly being washed down the drain.
"Firefighters were using 10,000 litres of fire water a minute," she said
"There was no way I was going to be able to capture the lot of this stuff."
Working with colleagues from Fire Rescue Victoria and Melbourne Water, the team followed the water through the drain into a retarding basin on nearby Chandler Road.
They had to plug the basin, to stop the nurdles flowing into the Moorabbin Creek and out into Port Philip Bay.
"These things do not go away, and then fish eat them and they do contain contaminants," Ms McGregor said.
In 2017, millions of the microplastics washed up on the beach at Warrnambool, in south-west Victoria.
Locals told the ABC they picked up 4,500 nurdles by hand, in just a three-metre square.
Two Olympic swimming pools of water removed
Melbourne Water's general manager of waterways and operations, Rob Considine, was on site at the retarding basin in Keysborough, where he saw the nurdles accumulating in the long reeds.
He called in earthmoving equipment to remove the vegetation, and to dig a big trench to hold all the water.
"Two million litres of contaminated water containing the nurdles was removed — that's 200 trucks or two Olympic swimming pools," he said.
The contaminated water was trucked away and treated at a treatment plant.
Ms McGregor said the result was "phenomenal".
"This is a massive win," she said.
The clean-up is estimated to cost up to $5 million, and the investigation into the fire is ongoing.
Increase in potentially damaging fires
That was one of four fires the EPA was called to in February 2023 — and that number is increasing.
Since July 2021, the EPA has been called to 71 fires across Victoria — many of them in Melbourne's industrial areas.
In the first three months of 2023, the EPA has already been called to 21 fires.
Mr Considine said population growth was part of the reason.
"As Melbourne grows, we've grown about a million people in the past decade, so there's just more stuff around, in more dense settings as the suburbs get denser," he said.
"We've also become more conscious of the impact these spills can have on our waterways."
Melbourne Water manages 25,000 kilometres of rivers and creeks across the city, including preventing pollutants from spreading.
"It's a lot of contamination if we don't catch it and stop it getting into our rivers and creeks," he said.
EPA puts businesses on notice
The EPA's chief executive, Lee Miezis, said the onus was on businesses to do all they can to prevent a fire, and then to prevent any environmental damage a fire might cause.
"We want to know that they've got good fire controls in place — that could be sprinklers, it could be early detection systems," he said.
He said the EPA was prosecuting 90 cases before the courts.
The EPA has conducted 350 inspections as part of its fire prevention program since July 2022, and issued 10 sanctions.
It has also conducted 388 inspections at industrial precincts near waterways, and issued 75 notices.
Investigations are ongoing after a factory fire in Melbourne's west led to a chemical spill that saw 20 tonnes of dead fish removed from Cherry Lake in Altona.
Lee Miezis said the EPA has enough power to hold businesses to account, but prevention is the best approach.
"The only thing that should go down our drains is rain," he said.
