A Wellington company has begun trialling technology at Lower Hutt’s Silverstream Landfill that it says can destroy asbestos fibres and turn them into a safe material suitable for reuse in concrete, in what would be a New Zealand first if the trial succeeds.
Environmental Decontamination Limited, known as EDL, formally launched the trial on Thursday with the backing of Hutt City Council, which has put 365,000 dollars of its yearly waste levy into the project. The technology grinds asbestos using metal balls travelling at high speed, breaking the fibres down and altering their chemical structure so that they no longer pose a health risk.
Asbestos was banned outright in New Zealand in 2016 but remains buried in thousands of homes, schools, public buildings and industrial sites built before the ban. Loose fibres become dangerous when they are released into the air, where they can lodge in the lungs and cause mesothelioma and other serious illnesses decades later.
At present, the only legal way to deal with asbestos waste in New Zealand is to seal it in plastic and bury it in a small number of certified landfills. Silverstream alone takes between 2000 and 3000 tonnes a year, at a cost of 398 dollars a tonne to the consumer and only with prior council approval. The waste sits in the ground indefinitely, and the long term liability for keeping it sealed falls to whichever generation happens to be in charge of the site.
Lower Hutt mayor Ken Laban said the trial was a chance to step away from that model.
“For decades, asbestos had been buried and left for future generations to manage,” Laban said. “This trial gives us the chance to explore a safer and more sustainable alternative to simply burying asbestos waste.”
EDL chief executive Marcus Glucina was careful to set expectations.
“This trial is not about making big claims before the evidence is in,” he said. “It is about gathering the evidence needed to understand whether this technology can work safely on a global scale.”
The work is being run by specialist engineers and scientists with previous asbestos handling experience, under strict containment and air monitoring controls. Final findings are expected before the end of the year, EDL says.
If the technology lives up to the company’s expectations, the resulting material would not just be safe, it would have commercial value. The end goal is to sell the treated material into the concrete industry, which already uses ground mineral additives in cement and aggregate blends. That would flip the economics of asbestos disposal, turning a waste stream that currently costs hundreds of dollars a tonne into a feedstock that has a price tag attached.
Laban said that, if the trial succeeded, the implications would extend well beyond Lower Hutt.
“It could change asbestos waste in New Zealand and around the world,” he said.
The scale of the legacy problem is significant. Asbestos was widely used in New Zealand from the 1940s through to the 1980s in roof sheeting, eaves linings, vinyl floor tiles, insulation, pipe lagging and fibrolite walls. Most pre 1990 houses still contain some asbestos somewhere on site, and demolition and renovation work routinely turns it up. WorkSafe still records asbestos related notifications every week, and the disease burden from past exposures is forecast to peak in the 2030s as old workplace cases work through.
For councils, the cost is starting to bite. Schools have been hit with one off bills in recent years after coloured play sand was found to be contaminated with the fibre, and any storm or earthquake event that damages older buildings generates a spike in asbestos waste that has to go somewhere. Silverstream is one of only a handful of sites in the lower North Island that can take it, and capacity is finite.
A workable destruction technology would also matter for the demolition industry. Builders and removal contractors currently pay heavily to transport sealed asbestos to certified disposal sites, and the bills are passed straight on to homeowners doing renovations. Anything that lowers the cost and shortens the logistics chain would change the maths on whether to remove or simply contain asbestos in a building.
EDL is keeping the technical specifics of its process commercial in confidence, but the principle behind it, using mechanochemical milling to alter the crystalline structure of asbestos fibres, has been studied internationally for more than two decades. The challenge has consistently been doing it safely and at industrial scale, with adequate dust control. That is what the Silverstream trial is intended to prove or disprove.
For now, the asbestos sitting in the ground at Silverstream is staying where it is. But if the engineers and scientists running the trial come back with a clean result before December, Lower Hutt may end up being remembered as the place where one of New Zealand’s most stubborn waste problems started to come undone.
Read more at RNZ.
What do you think, should councils be putting more money into solving the asbestos legacy rather than just burying it? Have your say in the comments below.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂
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