Asbestos in concrete – is it safe to recycle?

Concrete recycling in Taupo has been suspended and there is currently no concrete available for recycling. File photo.
photo: 123 RF

The discovery of asbestos in concrete designated for recycling by the City of Taupo has raised questions about the viability of concrete recycling across the country.

Taupo District Council says it is testing stockpiled waste concrete after asbestos was found in concrete at the Broadlands Road landfill.

The council would normally crush the concrete and sell the recycled material to customers for use in building roads and driveways.

But after crushed concrete used in municipal projects was suspected to contain asbestos, the government took samples from the landfill’s concrete stockpile. Small amounts of asbestos were found in two of the samples.

Council chief executive Julie Gardyne said concrete recycling has now been suspended and no concrete is currently being accepted for recycling.

Around 50% of waste comes from the construction and demolition industry, of which 90% (such as concrete) can be reused, recycled or returned to suppliers.

Construction company Naylor Love is a strong advocate of waste diversion within the industry. Waikato environment manager Stephanie Mayer told RNZ in 2023 that the average construction site only diverted 17 per cent of its waste; on a recent project in Hamilton, the company was aiming to divert 80 per cent.

Some of that comes from concrete recycling, and its Waikato/Bay of Plenty operations manager Dean McGahey is concerned about what the Taupo findings mean for concrete reuse.

“Unfortunately, given the cost of landfill disposal, waste concrete may be dumped into the environment, which could pose a greater risk to the public,” he said.

But he supports the council’s approach.

“I think the council has taken a sensible and responsible approach, unfortunately asbestos was common in many building products before 2000 and some people may not be aware of that.”

Meyer believes that recycling of concrete crushers can only go forward if all materials are tested first.

“Hopefully they can figure out some way to test the concrete before people bring it there (to be recycled),” she said.

Asbestos inspector Garry Godfrey said asbestos had even been found in products such as baby powder and clothing in the past, and he reminded people that asbestos was only dangerous if inhaled in dust form.

“It doesn’t mean that if you breathe in asbestos today, you’re going to die tomorrow, because that’s not the case. Not everyone gets asbestosis. We’ve never really established the limits of exposure to asbestos,” Godfrey said.

There are several laws that regulate the use and removal of asbestos. WorkSafe advises that building contractors must by law ensure that asbestos is identified and removed before any demolition or renovation work that could disturb the asbestos begins.

“I think the City of Taupo itself has a very good process in that they do require testing. The council requires testing to be done on most buildings before they allow any work to be done there,” Godfrey said.

It is therefore surprising that asbestos products have ended up in the council’s concrete recycling scheme.

Taupo District Council said it was taking expert advice on how to respond to asbestos discoveries and had been advised it would need to undertake an extensive sampling programme to truly understand the asbestos levels in its concrete stockpile.

So far, 12 samples have been collected from the landfill stockpile, 10 of which tested safe and two samples showed low levels of contamination.

The council said it was working directly with customers known to have purchased crushed concrete to have it tested and if asbestos levels exceeded safety standards, the council would work with customers to make the site safe and remediate where appropriate.

Mr Gadeen asked anyone with concerns about concrete material purchased from Broadlands Road landfill to contact the council, and reiterated that while asbestos had been found, levels of contamination in samples were currently low.

“We are taking an extremely cautious approach to this situation and while we expect test results to continue to show safe or low contamination levels, we want to make every effort to ensure any broken concrete that could pose a risk to the community is identified and addressed.”