Asbestos contamination isn’t a static issue. Materials can move through soil and water systems and dramatically alter your site’s risk profile.
Understanding how asbestos behaves in the environment and how to identify small changes is critical in developing a robust safety and compliance program.
In this guide, we explain how asbestos moves through soil and water and how our consultants design investigations that account for redistribution. For more, get in touch.
Asbestos is typically found within asbestos containing materials (ACMs) like cement sheeting, insulation and building debris. In time, these materials break down into smaller fragments and fibres that can penetrate ecosystems.
The way and degree to which asbestos moves depends on:
Whether it is friable or non-friable
The condition of the material
The surrounding soil type and moisture levels
Whether the site has been disturbed
Non-friable asbestos is typically more stable, while friable materials release fibres easily and are more likely to cause contaminated soils.
Removal, excavation and other physical disturbances are the most common ways that asbestos move through soil. Grading, trenching and landscaping pose a similar risk.
This is particularly relevant for:
Sites with buried demolition waste or fill material
Areas where fill has been imported without verification
Brownfield sites undergoing redevelopment
If asbestos is disturbed it will spread quickly and the area of contamination will rapidly increase.
In undisturbed conditions, asbestos will rarely move through soil. However, natural processes can trigger conditions ideal for redistribution.
Soil erosion, for example, can expose buried ACMs to the elements or transport fragments downhill. Cracking soils may bring asbestos closer to the surface and biological activity (such as root growth) can shift soil layers.
These processes are all slow burns, but they can still influence your site’s contamination profile over time.
Rainfall mobilises asbestos on the surface, particularly if the area in question is sloped or has poor drainage. Runoff can see those fragments carried into:
Low lying areas
Drainage channels
Waterways
It’s worth noting that this is more likely where ACMs are exposed or where potentially contaminated soil has been disturbed.
Asbestos fibres do not readily dissolve in water. However, very fine fibres can be transported through soil pores with moving water.
This type of redistribution is typically limited, but it can still contribute to the spread of contamination if conditions allow.
Asbestos movement is not strictly limited to soil and water processes. Airborne transport plays a key role in how contamination moves through the environment.
When asbestos containing materials are disturbed, fibres can become suspended in the air and settle in surrounding areas. This process redistributes contamination and exposes that new area to the soil and water movements discussed above. There is also an increased risk of human exposure during dry or windy conditions.
At West Soil & Water, our consultants have designed asbestos investigations that consider both the source and potential movement pathways of contamination.
Our process includes:
Assessing site history to identify how asbestos may have been introduced
Targeted sampling in areas where movement is likely
Evaluating how proposed works may further redistribute contamination
Our investigations are designed to provide a more accurate picture of site conditions and support remediation planning.
Asbestos contamination in soil and water isn’t necessarily confined to its original location. Whether through disturbance, movement or airborne transport, ACMs can spread across site and dramatically alter how you approach risk.
Recognising these processes is critical in designing effective and compliant remediation strategies. WSW is experienced in helping WA operators implement compliance focused programs that provide actionable data.
To learn more about guidelines for asbestos in soil and water or to arrange a consultation, get in touch.