Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 4/5)
Character Range: 1585281–1588204

apply to all Australian urban residential/public open space soils.

4.6.1         Calculation of soil quality guidelines for fresh arsenic contamination based on no observed effect concentration and 10% effect concentration toxicity data
All the available As toxicity data (apart from that of Song et al. 2006) were reported as total concentrations without making a distinction between added and background concentrations. The Hamon et al. (2004) method can predict the ABC for As in Australian soils. For European soils or toxicity studies, the Dutch background standardisation equation for As can be used (Lexmond et al. 1986):
    As= 0.4*(clay content + organic matter content)   (equation 5)

However, the As toxicity studies did not report the Fe and Mn contents (required by the Hamon et al., 2004 method) or the organic matter or clay content (required by the Lexmond et al. 1986 method) of the soils in which the toxicity was determined. Therefore, it was not possible to estimate the ABC nor express toxicity in terms of added concentrations. As a result, no ACL values could be calculated.

The situation for As was that:
    * there were sufficient toxicity data to use the BurrliOZ software
    * the data could not be normalised to the Australian reference soil
    * the toxicity data could not be expressed in terms of added concentrations
    * a background concentration for As could not be calculated.
Therefore, only a single numerical value was generated by the BurrliOZ SSD method for each of the three land uses (that is, areas of ecological significance, urban residential/public open space, and commercial/industrial).

The output was the SQG(NOEC & EC10) for that particular land use and no soil-specific SQG(NOEC & EC10) values could be calculated. The As SQG(NOEC & EC10) values for the three land uses are presented in Table 31.
Table 31. Generic soil quality guidelines based on no observed effect concentration and 10% effect concentration toxicity data (SQG(NOEC & EC10)) for fresh arsenic (As) contamination in soil with different land uses.
Land use                             SQG(NOEC & EC10)
                                     (mg/kg total As)
Areas of ecological significance     8
Urban residential/public open space  20
Commercial/industrial                30

It should be noted, because As has generic SQG(NOEC & EC10) values, that they should be applied to all Australian soils that have the particular land use.

4.6.1.1         Calculation of ambient background concentration values
Despite the fact that ACLs could not be derived for As, the issue of background concentrations of As in Australian soils will be discussed as the situation could change in the future if additional data becomes available. If, in the future, toxicity data can be expressed in terms of added concentrations, it is recommended that the method of Hamon et al. (2004) be used to derive ABC values.