Tens of thousands of dumped cylinders, and even more tonnes of contaminated soil – this is the work required to cleanse a dump.
About 15 kilometres from Kaniva in Victoria’s North-West, near a region called “The Little Desert,” lies 600 hectares of arid bushland which harbours a toxic wasteland.
Through the scrub, emus, echidnas, goannas, kangaroos and small wallabies weave their tracks on the white sands while yellow-tailed black cockatoos – and their even rarer red-tailed cousins – screech and soar overhead.
Chemical experts are in the sand dunes trying to avert an environmental disaster.
In late March 2020, the Victorian Environmental Protection Agency (EPA) charged the site’s owner, Graham Leslie White, with 118 offences under the Environment Protection Act.
The charges allege that he permitted the transport and burial of various types of industrial waste at his rural premises at Lemon Springs, and they also allege that unlawful dumping created an environmental hazard and polluted both land and water on the site.
The charges came to light after an investigation into the storage of chemicals at sites across Melbourne and regional Victoria.
When the Australian Federal Police, Victoria Police and the EPA first attended the site in 2018, there was no way of knowing the extent of the illegal dumping.
One of the first people from the EPA on the ground was Julian Bull, tasked with project managing the site clean-up. Working out what was buried, how much and where, quickly grew into a multi-headed Hydra-like beast of a problem.
“We came in knowing we’d be dealing with a lot of flammables, and hazardous liquid waste as these were connected with investigations on other sites,” he says.
Of particular concern, was the potential for contamination of the regional aquifer running through Victoria, South Australia and New South Wales, and the subsequent danger to communities and business.
But to write a tender for clean-up, the EPA needed to know exactly what they were dealing with.
“Everything was buried,” says Bull. “We just didn’t know what was there.”
A preliminary investigation revealed an unpleasant surprise.
“We opened up three locations,” he says. “The first two had heaps of liquid waste as expected. Site 13 was an extra add-on. When we opened it up, it was full of acetylene cylinders. We had no idea how many to expect.”
Since then, the list of contaminants from a total of 32 sites is long and complex: a vast variety of different chemicals – PFAS, acids, solvents, resins, pesticides, phosphine, chlorine, oxidisers, flammables, explosives, hydrocarbons, paints and oils – and solid wastes including medical sharps, asbestos, airbag detonators, drums and concrete slurry.
The landscape is now dotted with piles of dirt, excavated pits, evaporation ponds, black plastic, site offices, a huge triage building and a storage pad for the 51,000 (and counting) acetylene cylinders found to date.
It’s been a long road.
Some of the waste was so mixed and compacted it was impossible to tell exactly what it was.
“We thought around 70% of the barrels coming out of the ground would be intact,” says Bull. “We ended up getting about 10% that were okay, the rest were just crammed in, a layer of soil dumped on top and then run over with an excavator. Most were crushed and in terrible condition.”
The discovery of friable asbestos, amongst other contaminants, has required an ever-evolving safety plan and the acquisition of an expensive decontamination unit to keep workers safe.
In some spots, the soil contamination was so severe and untreatable, it was immediately sent for incineration.
Liquid waste is still being triaged, decanted and then bundled into separate areas based on type. “Some, you can’t make heads or tails of, so it’s sent to Cleanaway in Adelaide for fixation, which involves mixing with cement and putting it into landfill,” says Bull.
Other liquid waste, however, can be reused.
“We’ll send them to where they should have gone in the first place. Geocycle in Melbourne takes a lot of the class threes. They’re used as fuel in cement kilns, for instance.”
Among all the toxic gloom is a silver lining: 150km as the crow flies, on the outskirts of the small regional town of Stawell, the clean-up team has arranged for Australia’s first ever acetylene cylinder recycling facility to be built.
Acetylene, with its extremely high flame temperature, is used for welding and cutting operations, and as a fuel. It’s unstable and prone to spontaneous explosion, however, so cylinders typically contain a porous membrane of asbestos, with liquid acetone to stabilise it.
These cylinders have a 30-50-year life cycle, but Bull estimates that around Australia, about 20,000 of them are pulled out of circulation every year due to defects including dents and cracks.
“At the moment, no one is regulating,” he says. “No one’s saying to the gas companies, ‘you can’t store them all out in a paddock’. Yes, they’re told to make sure there are fire controls and make sure they don’t go bang. But no one’s saying ‘you need to get rid of them, you need to recycle them’.”
The EPA saw an opportunity.
The tender for the Stawell plant was written to ensure that the successful contractor would not only deal with the cylinders from the site in Kaniva but take in and recycle those from industry afterwards.
It’s not a simple process, and neither is it cheap.
“We can’t degas all the acetylene onsite because of the porous mass and the acetone,” explains Bull. “The flammable acetone is still in there and it’s explosive, although not to the same extent as acetylene. So, there’s still a risk in transportation and storage.”
The cylinders will first be washed to remove external contaminants and new plugs fitted. Wastewater will be treated and used onsite.
“There’s a lot of manual preparatory work, which is expensive,” he says.
Up to 85 cylinders at a time will be tapped into a specialised unit purchased from the United States. Over 24 hours the cylinders will be heated to 90°C, releasing acetone from the asbestos. The tiny amounts of acetylene will be off-gassed to the atmosphere, while the acetone will be condensed, collected and sent for use in industry.
After cutting the top and bottom off the cylinders, the asbestos will be removed and sent for disposal in landfill facilities in Stawell which are already equipped to deal with asbestos.
The tender conditions require the successful contractor to gain the necessary EPA and WorkSafe licences and also achieve appropriate levels of noise, asbestos exposure and acetylene off-gas levels. “We will obviously be monitoring levels coming out to ensure they’re well below restricted levels,” says Bull.
Finally, the remnants of the cylinder, the clean steel, will be ready for reuse and recycling.
Back on site, things are getting better every day.
“We’ve got several sites to backfill, so when we can treat contaminants, we do, and we treat back to a suitable level defined by our independent auditor,’ says Bull.
“It’s fairly conservative because of the pristine nature of the land. We’re putting soil back with cleaner levels of contaminants than clean-fill soil you can buy.”
Key to soil treatment and reuse are “biopiles”. These are layers of contaminated soil with added microbes, phosphates and other nutrients, which are then covered in black plastic. Special SVE units monitor the piles, giving an indication of the improving bioremediation condition of the soil.
Once backfilled, the landscape can start reseeding itself. “About 10-15% of the actual block is affected, and many of the finished areas are already starting to regenerate,” says Bull.
The hope is that in a few years, the only visible disturbance in the sands of the site will be the footprints of animals scattered through the scrub.
Originally published by Cosmos as After years of work, the toxic waste dump south of Kaniva is finally starting to come clean
Clare Kenyon is a science journalist for Cosmos. An ex-high school teacher, she is currently wrangling the death throes of her PhD in astrophysics, has a Masters in astronomy and another in education. Clare also has diplomas in music and criminology and a graduate certificate of leadership and learning.