Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:6:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 6 (pt 4/5)
Character Range: 1620023–1623076

b to protect 85% of species, c to protect 65% of species.
It should be noted that if a site-specific ABC for DDT is determined (and there is sufficient justification for this ABC to be used instead of the default value of 0 mg/kg) then it may be added to the above generic SQG(NOEC & EC10) values to obtain a site-specific SQG(NOEC & EC10). As the values in Table 43 are generic SQG(NOEC & EC10) values they should be applied to all Australian soils that have the particular land use.

6.6.2         Calculation of soil quality guidelines for fresh DDT contamination based on lowest observed effect concentration data and 30% effect concentration data, and based on 50% effect concentration toxicity data
The SQG(LOEC & EC30) and SQG(EC50) values were calculated using the same method as that for the corresponding values for Zn, As and naphthalene. The data used to calculate these SQGs is presented in Table 42. To maximise the data available to generate the SQG(LOEC & EC30) and SQG(EC50) values, the available toxicity data was converted to the appropriate measure of toxicity using the default conversion factors recommended in  Schedule B5b and presented in Table 30.

As with the SQG(NOEC & EC10) values for DDT, soil-specific SQG(LOEC & EC30) and SQG(EC50) values could not be generated, so rather a single generic SQG(LOEC & EC30) and SQG(EC50) was generated for each of the three land uses (Table 44). As these are generic SQGs, they should be applied to all Australian soils with the particular land use.

Table 44. Soil quality guidelines for DDT in freshly contaminated soil with different land uses based on lowest observed effect concentration and 30% effect concentration toxicity data, and based on 50% effect concentration toxicity data.
Land use                             SQG(LOEC & EC30) (mg/kg total DDT)  SQG(EC50)
                                                                         (mg/kg total DDT)
Areas of ecological significance     3                                   6
Urban residential/public open space  180                                 360
Commercial/industrial                640                                 1300

6.7              Calculation of soil quality guidelines for aged contamination
There is currently no ageing or leaching factor available for DDT and therefore SQGs for aged contamination could not be derived.

6.8              Reliability of soil quality guidelines
The DDT SQGs were considered to be of moderate reliability as the toxicity data set met the minimum data requirements to use an SSD method but there were no normalisation relationships available to account for soil characteristics (Schedule B5b).

6.9              Important metabolites of DDT
The most common metabolites of DDT are shown in Table 45. DDE is a well-known metabolite of DDT and is relatively well studied. However, there is considerably less information available on the environmental fate, metabolism, degradation and toxicity of these metabolites than on DDT. The HILs and some soil quality guidelines use a