Most people in construction think of asbestos as a building problem, cement sheet, pipe lagging, vinyl backing, all of it manufactured and installed by someone. Naturally occurring asbestos is different. It formed in the rock, and it's been sitting in the ground for a very long time waiting for someone to cut a road through it.
For civil, quarry and earthworks projects in the wrong geology, that's a live risk and one that rarely appears in the project risk register until it's already causing a problem.
Naturally occurring asbestos, or NOA, is asbestos mineral that forms in rock through geological processes. In eastern Australia it turns up most often in serpentinite, ultramafic rock that's been altered over time, usually as thin chrysotile veins running through the rock mass. Central Queensland has known chrysotile-bearing ultramafic belts. So does the New England region of NSW, along the Great Serpentinite Belt. Deposits exist in every Australian state.
The point is not that these areas are dangerous to stand in. Undisturbed NOA generally isn't a health risk. The risk is created by the work: excavation, blasting, crushing, grading, hauling and anything else that breaks the rock up and puts dust in the air.
Three reasons, over and over.
The first is that a site history search won't find it. There's no former land use to flag, no demolition record, no imported fill to investigate. A site can be pristine bushland and still sit on top of an asbestos-bearing formation.
The second is that NOA doesn't look like asbestos. Fibrous veins in rock are easy to walk past, and even where they're visible, confirming the mineralogy takes laboratory analysis. Field judgement isn't enough.
The third is that the usual playbook doesn't apply. With a building, you find asbestos, you remove it, you get a clearance and you move on. You cannot remove a geological formation. NOA has to be managed in place, dust suppression, exclusion zones, air monitoring, controlled handling and haulage, and a management plan that holds up under scrutiny.
That last point is where programs get hurt. A team geared up to remove a hazard discovers the hazard is the site itself, and works stop while everyone figures out what to do.
Under WHS regulations, once asbestos is identified or is likely to be present, you have a duty to manage it, which means an asbestos management plan and controls appropriate to the work. The regulatory obligation isn't the hard part. The hard part is finding out about it in week 12 instead of week zero.
Recent roadworks in regional NSW show how differently this plays out with early information. NOA was confirmed in samples taken before major works, and the design approach shifted, resurfacing over the existing pavement rather than excavating into material that would have needed extensive controls and disposal. Same road, far less disruption, because the sampling happened first.
That's the version we want for our clients. Assess the geology and the proposed disturbance early, sample where the risk is real, and build the controls into the methodology and the program rather than bolting them on under pressure. Regulations don't have to slow a project down. Discovering things late does.
If your project involves ground disturbance in an area with ultramafic or serpentinite geology, road corridors, quarries, pipeline routes, bulk earthworks, regional infrastructure, get NOA screening into the early works assessment. It's a small cost against the alternative, which is a stopped site and a management plan written in a hurry.
We physically sample suspect material rather than presuming what it is, and we stay involved through monitoring, controls and sign-off rather than handing over a report and disappearing.
Talk to the BBN team about your next project. We'll tell you whether NOA is a real risk on your site or not, and either answer is useful.
What is naturally occurring asbestos (NOA)?
Asbestos mineral that formed in rock through geological processes, rather than being manufactured and installed in a building. In eastern Australia it's most often found in serpentinite, ultramafic rock altered over time, usually as thin chrysotile veins running through the rock mass.
Where is it found in Australia?
Deposits exist in every state. Central Queensland has known chrysotile-bearing ultramafic belts, and the New England region of NSW has the Great Serpentinite Belt. Because NOA is geological rather than historical, a site can have no prior land use of concern and still sit on an asbestos-bearing formation.
Is it dangerous if it's left undisturbed?
Generally not. The risk is created by the work, excavation, blasting, crushing, grading and hauling all break the rock up and can release fibres into the air. That's why the assessment focuses on the disturbance proposed, not just the presence of the mineral.
Can it be removed from a site?
No. You can't remove a geological formation the way you remove asbestos cement sheeting from a building. NOA is managed in place through dust suppression, exclusion zones, air monitoring, controlled handling and haulage, and a documented management plan. Project teams expecting a removal and clearance process are often caught out by this.
Do I need an asbestos management plan for NOA?
Yes. Under WHS regulations, once asbestos is identified or is likely to be present, there's a duty to manage it, an asbestos management plan and controls appropriate to the work. The obligation applies whether the asbestos is manufactured or naturally occurring.
How do you test for it?
Physical sampling and laboratory analysis of the rock or soil. Fibrous veins are easy to walk past on site, and visual identification isn't reliable, the mineralogy has to be confirmed in a lab. We sample suspect material rather than presuming what it is.
Which projects should include NOA screening?
Any project involving ground disturbance in ultramafic or serpentinite geology, road corridors, quarries, pipeline routes, bulk earthworks, regional infrastructure. Screening belongs in the early works assessment, before the methodology and program are locked in.
