Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:10:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 10 (pt 4/4)
Character Range: 1753168–1755227

data and the overlaps in the sensitivity of the organism types, all the Cr (III) toxicity data was used to derive the SQGs.
Figure 10. The SSD (plotted as a cumulative frequency against added trivalent chromium (Cr (III)) concentration) of Cr (III) for soil invertebrate species, plant species and soil microbial processes.

10.6          Calculation of soil quality guidelines for fresh trivalent chromium contamination

10.6.1     Calculation of added contaminant limits for fresh trivalent chromium contamination
Only the Cr (III) toxicity data for E. fetida and E. andrei could be normalised to the Australian reference soil. Thus, a set of generic ACLs and a set of soil-specific ACLs were derived (for the earthworms). The soil-specific ACL values below a clay content of 10% were smaller than the generic ACL values. The soil-specific ACL at a clay content of 10% equalled the generic ACL, and all soil-specific ACLs for soils with a clay content greater than 10% were larger than the generic ACLs. The lower of the soil-specific ACL values and the generic ACL values were adopted as the final ACLs for Cr (III). Thus, the situation was simplified to the soil-specific ACLs only applying up to a clay content of 10% at which point the generic ACL values apply. The generated ACLs for the three land uses and the three types of toxicity data (that is, NOEC and EC10, LOEC and EC30, EC50) are presented in Table 85.

The range between the largest and smallest ACL values generated was approximately 4.0 to 470 mg added Cr (III)/kg. The residential/urban ACLs based on NOEC and EC10, LOEC and EC30, and EC50 data ranged from 3575, 75160, and 110230 mg added Cr (III)/kg respectively.

Table 85. The ACLs based on NOEC and 10% effect concentration (EC10) data, LOEC and 30% effect concentration (EC30), and 50% effect concentration (EC50) toxicity data for trivalent chromium (Cr (III)) for various land uses. These are based on all the Cr (III) toxicity data, except the catalase and nitrogenase enzyme activity data.
Data type  Land use  Clay content