Asbestos Containing Soil or Asbestos in Soil (ASBINS)
Asbestos contamination in soil and contaminated sites are common occurrence in Australia. The contamination can be a result of poor remediation or demolition of structures, deterioration of materials in-situ, historical burial of asbestos, contaminated fill or even illegal dumping of hazardous waste.
OHMS Asbestos operate a risk-based approach in relation to the management and remediation of asbestos soil contamination in line with the Department of Healths Guidelines for the Assessment, Remediation and Management of Asbestos-Contaminated Sites.
Where there is a presumption that a site is contaminated with asbestos it is recommended a preliminary site investigation (PSI) is undertaken. This involves an investigation of records and available material of the site history. It may also include a site walkthrough to identify possible surface contamination. Based on the findings of the PSI a detailed site investigation may be actioned which would involve sampling of the soil to identify hot spots and quantify the location of the contamination.
Nature of Asbestos Contamination
When we consider the nature of asbestos contamination it can be in a range of forms:
- Asbestos Containing Material (ACM) is the most common form of contamination. It is typically in sound condition, although possibly broken or fragmented, and the asbestos is bound in a matrix; for instance, asbestos fencing or vinyl tiles. This is also restricted to material that cannot pass through a 7mm x 7mm sieve.
- Fibrous material (FA) is friable (un-bonded) material such as weathered ACM or loose material such as insulation. FA and ACM alike can usually be detected visually.
- Asbestos Fines (AF) involves free asbestos fibres, small bundles and ACM that can pass through a 7mm x 7mm sieve.
The nature of the asbestos contamination and the proposed ongoing usage of the land assists OHMS Asbestos in advising the most suitable control measures or remediation techniques.
Asbestos Contamination and remediation Techniques
Potential remediation techniques may include:
- Hand pick (commonly referred to as emu pick, emu bob, chicken pick or sparrow picking) is only suitable for ACM that is visible to the surface;
- Tiling is a methodology used when the ACM contamination is identified to be no greater than 30cm in depth. It involves mechanical means to conduct the works.
- Screening if undertaken correctly can provide a high level of confidence that the processed soil achieves the required standard of cleanliness.
- Removal off site involves the excavation of the affected soil and disposal at a licensed facility. Often another location on the same site can be identified for burial of the material which negates the cost of disposal however this essentially only shifts the problem to another location and requires an ongoing asbestos management plan.
Contaminated land often has a Memorial on Title (MOT) which can impact on future sales or land usage. Through liaison with the client OHMS Asbestos understanding of the issues arising with asbestos in soil can help assist in the ongoing management or remediation of the affected land.