Written by Brett Abraham, Principal Consultant at Survey Asbestos | Thomas Consultants

What happens when asbestos ends up in the ground?

Asbestos is a mineral which is naturally found, but in most cases it ends up in the soil because of human activity.

Common scenarios for inground contamination are:

ACM waste products used as imported fill
Illegally dumped asbestos
Inadequate identification, removal, clearance and decontamination of asbestos before building demolition
Rainwater and wind transporting fibres from degrading asbestos to the ground e.g. super-six roofs.

Asbestos itself is very stable and can remain in the soil indefinitely. Asbestos containing products may degrade over time, especially in acidic soils, with the asbestos fibres being released but remaining in the soil if undisturbed.

What are the health risks?

The health risk to humans only arises when the fibres in the soil become airborne. Keep in mind that asbestos in soil is typically inert, does not degrade quickly, is not readily mobilised into air and once buried only migrates through erosion, physical movement or when it is airborne.

What are the triggers for Asbestos Contamination?

There are many triggers for considering whether possible asbestos contamination in the soil needs to be considered. Triggers include:

Subdivision
Changing the land use
There are known or reasonably likely exposure to respirable asbestos fibres in the work place
Activities that will result in soil disturbance
Public observation of potentially unsafe asbestos practices

If one of the above reasons are triggered, key aspects to consider if asbestos contamination may be present are:

Is ACM present or suspected present based on age, composition, industry evidence of demolition, location and interviews?
Is the ACM in a condition which can lead to fibre release?
Can you see evidence of suspected external ACM such as cladding, roofing, guttering etc?
Do which indicate that asbestos was present?

It is always a good idea to get a professional asbestos surveyor to answer these questions for you, to ensure you do not miss anything which might indicate that ACM is present at the property that may lead to soil contamination.

Source of below picture is branz.co.nz