With shifts in social and global dynamics forcing a rethink of deep-rooted environmental issues, Australia is poised to remodel its approach to remediation.
From 1964 to 1973, the American military sprayed 80 million litres of Agent Orange on Vietnam. Still found in soil in the form of dioxin, the harmful herbicide represents a highly toxic element for Vietnam’s population and environment.
In 2012, the Vietnam Ministry of Defence and the United States Agency for International Development launched a project to treat 87,000 cubic metres of soils and sediments near Da Nang airport.
Veolia, who were tasked with carrying out the project, chose the only technology capable of meeting the set target with the least environmental impact: in-pile thermal desorption.
The process involves heating the earth to 335 degrees Celsius for several months, forcing the dioxins to evaporate and be destroyed
In concrete terms, a huge structure 100 meters long, 70 meters wide and eight meters high was built on airport land. Initially, 50 per cent of the earth was transported there by truck.
Once the container was filled, 1252 heating wells were sunk into the soil.
The structure was then covered in order to be able to treat the gaseous effluent in situ. Liquid effluent was also collected for treatment.
After ten months, the earth could be used as filler material for Da Nang airport.
Matt Ead, Veolia Australia and New Zealand Remediation Service Manager, highlights the Agent Orange clean-up project as a key example of Veolia’s technical capabilities, as well as its commitment to using said capabilities to support the communities in which it operates.
Sustainability is critical to the future and health of the world’s cities and communities, he says, with shifts in social and global dynamics forcing a rethink of legacy environmental impacts.
“In the past, Australia’s approach to both soil remediation and waste management broadly, was to ignore the problem and bury it in landfill,” Matt says.
“Whereas overseas, they have had to be smarter about it because they don’t have the landfill space that Australia has been blessed with, so to speak.”
With Australia’s environmental mindset changing at both legislative and community awareness levels, Matt says a lot can be learned from international experience and best practice.
“Australia is moving into a more technological space when it comes to soil remediation, and Veolia is at the forefront of that ecological transformation,” he says.
“Our extensive experience overseas is a major point of difference. We have trialled and tested our processes and technological capability to deal with material in situ, rather than digging up the ground and shifting the problem.”
Matt adds that Veolia’s international footprint facilitates a knowledge transfer network.
“We’ve got people working on remediation projects in France, Taiwan, Denmark and all of Europe,” he says.
“We all talk regularly to share information and ideas. If there’s a difficult project here in Australia, chances are we’ve dealt with similar problems elsewhere and can apply those learnings here.”
With the move towards more ecologically sustainable solutions, paired with scarcer landfill space and rising levies, Matt says Australia is ready for a high-level technological approach to remediation.
Veolia offers cradle to grave remediation solutions – from facilitating regulatory approvals and community relations activities, to developing environmental management plans and arranging engineering design for onsite retention including civil works.
To decontaminate soils and liquids, Veolia employs a range of tested technologies including containment, chemical and physical stabilisation, chemical hydrocarbon treatment, low temperature indirect thermal desorption, bioremediation and solvent extraction.
Several of Veolia’s technologies are based on a fast reaction time, usually measured in hours as opposed to weeks or months with conventional treatments – thereby minimising potential contamination and considerable time savings on critical projects.
“We’re one of the only companies that can offer that full cradle to grave service,” Matt says.
“We have experts in water treatment and the technology to deal with soil, as well as hazardous waste facilities that can process spent material for disposal or recovery.”
As inner-city development progresses and populations continue to rise, Matt notes that industrial sites that were once situated on the outskirts of major cities are now surrounded by communities of people.
“If we look at Melbourne, areas like Footscray, Yarraville and Altona used to be industrial areas but are now trendy suburbs with people living all around,” he says.
“Industry is moving on, but there are still a lot of contaminated sites. That’s a real driver to grow the remediation sector.”
While Melbourne’s Maribyrnong Defence Site sits on a picturesque bend of the inner-city suburb’s river, it has been abandoned for more than a decade – badly contaminated following years of explosives being manufactured and tested by the defence force.
The 128-hecatre site would represent prime real-estate for property or environmental development, Matt says.
However, it’s been left abandoned due to complex contamination issues.
Veolia has extensive experience dealing with unexploded ordinance, Matt adds. He notes a project at the former 217 air base in Bretigny-sur-Orge, France, which began in 2014 and concluded in late 2019.
The project involved Veolia scanning the 300 hectare site using specialist radars looking for grenades and bombs dating back to the Second World War.
In total, this site uncovered over 15,000 “targets”, 40 or so which were still active.
Through treating extreme pollution and comprehending, managing and neutralising the risk of explosion, Veolia freed the land to host public facilities, light industry, housing and urban farming.
“Remediation technology, be it to deal with unexploded ordinance, PFAS or general industrial contamination is available,” Matt says.
“What’s needed is a rethink of current approaches and an understanding of social licence.
“We shouldn’t be ignoring problems because they are perceived to be too difficult, but rather using the technology that’s available and managing the problem now.”
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