Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p9
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 9/11)
Character Range: 140457–143250

fibres associated with bulk screening.)

A comparable gravimetric assessment approach may be applied to FA when large discrete pieces (e.g. asbestos gaskets and pieces of asbestos 'rope') are present in soil, however care should be taken during their removal to minimise potential fibre release.

If bonded ACM is in poor condition or site conditions are likely to result in degradation (e.g. due to acidic soil conditions) then the bonded ACM should be assumed to be FA for the purposes of comparing with the relevant screening level.

Schedule B2 and WA DoH 2009 (Section 4) provide more detailed guidance for sampling soil and determination of the %w/w asbestos in soil by gravimetric procedure.
Laboratory analysis
As yet there is no validated method, readily available in Australia, of reliably estimating the concentration of free asbestos fibres in soil. Soil contamination by free asbestos fibres should therefore be simply determined according to the presence or absence of fibres, in accordance with AS4964 – 2004: Method for the Qualitative identification of asbestos in bulk samples (Standards Australia 2004) by a laboratory accredited by NATA (or its mutual recognition agreement partners) for this method.

AS4964-2004 sets out a tiered approach to detecting the presence of asbestos (amosite, crocidolite and chrysotile forms) in soil samples using polarised light microscopy and dispersion staining techniques. If evidence of asbestos fibres is not found in the greater than 2 mm sieved fraction, a trace analysis is required of the residue (sub-2 mm fraction). Depending on the nature and size of the soil sample, the sub-2 mm residue material may need to be sub-sampled for trace analysis.

The nominal detection limit of the AS4964 method is around 0.01%. The examination of large sample sizes (at least 500 ml is recommended) may improve the likelihood of identifying asbestos material in the greater than 2 mm fraction.

Care should be taken in selecting samples for laboratory analysis to ensure that they comprise representative samples, as far as practicable, of the soil units to be tested or material from suspect areas. This may be difficult to achieve because of the complexity of the soil unit or large size of soil particles.

In the case of co-located bonded ACM, FA and AF, where significant asbestos may be present as fibrous asbestos or asbestos fines (greater than 10% (in total for FA and AF) of that present in the bonded ACM alone), then laboratory analysis may be necessary to assist with impact delineation. It may be possible in the initial AS4964 procedure to obtain an estimate of the weight of asbestos (such as small ACM fragments and fibre bundles) which does not pass through the 2 mm sieve. Depending on site circumstances, this information may