Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p8
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 8/11)
Character Range: 137795–140718

volume may be one or more individual 10 L samples from specific soil units or the area of a grid square multiplied by the investigation depth for raking and tilling methods (refer Schedule B2).

As outlined in enHealth (2005), the quantity of asbestos in soil may be estimated as follows:

                %w/w asbestos in soil = % asbestos content x bonded ACM (kg) /soil volume (L) x
                soil density (kg/L)

In the example included in enHealth (2005) it was assumed that:
    % asbestos content (within bonded ACM) = 15% and soil density (for sandy soils) = 1.65 kg/L
More representative results for asbestos concentration in soil can be calculated if the parameter values are analysed rather than assumed.

The assumption of 15% asbestos by weight in bonded ACM for sites contaminated with cement bonded ACM only is acceptable because typical compositions for bonded ACM products used in Australia are 1015% asbestos by weight. However, other bonded products may contain much larger proportions of asbestos, e.g. asbestos vinyl floor tiles may contain 830% asbestos (Workplace Health and Safety Queensland, 2011). The likely presence of bonded materials other than cement products should be addressed in the PSI and site inspection.  If found during sampling, the calculation will need to be adjusted either by making a conservative assumption or based on laboratory analysis of representative material from the site.

Soil densities are typically greater than about 1.5 kg/L (1500 kg/m3). The need to sample and analyse representative soil samples for soil density should be considered in the SAQP and will be required for dense and/or compacted soils.

The rationale for the calculation carried out, including the basis for all assumptions, should be documented in the site assessment report.

Depending on what is known of the site history and also the nature of the investigative methods used, the confidence in the calculation results will vary. In particular, hand-picking (using multi-directional raking and hand removal of fragments) and tilling surveys (mechanical turning over of surface soils to assist identification and collection of fragments) may provide less confidence compared with large volume mechanical screening (separation of fragments by automated sieving). Likewise, if the bonded ACM weight is estimated rather than measured, such as by estimating bonded ACM sheet area, then confidence in the results will be reduced. (Note that when considering which technique(s) to use that the increased confidence in results from mechanical methods should be considered in the context of the possible increased risk of releasing 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