Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:11:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 11 (pt 2/6)
Character Range: 1772820–1775876

identical to the lowest corresponding international SQGs, while the higher Zn ACLs are considerably larger than any international SQG.

Arsenic does not biomagnify in oxidised soils but has the potential to leach from contaminated soil to groundwater. Therefore, only the direct toxicity route of exposure needs to be considered in deriving the SQGs. The minimum data requirements to use the SSD method were exceeded, there were no normalisation relationships, and an ageing/leaching factor was available.

The toxicity data could only be expressed in terms of total As concentrations, therefore moderate reliability generic (not soil-specific) As SQG(NOEC & EC10), SQG(LOEC & EC30) and SQG(EC50) values could be derived for:

    * fresh contamination
    * aged contamination
    * protection of aquatic ecosystems
    * areas of ecological significance, urban residential/public open space, and commercial/industrial land uses.

The generic As SQG(NOEC & EC10) value for soils with areas of ecological significance, urban residential/public open space and commercial/industrial land uses were 8, 20 and 30 mg/kg (total As) respectively. The SQG(LOEC & EC30) and SQG(EC50) values were approximately 2.55 and 3.755 times larger, respectively, than the corresponding SQG(NOEC & EC10) values. The As SQG(NOEC & EC10) for urban residential/public open space soils is identical to the superseded interim urban EIL of 20 mg/kg (NEPC1999). Both the As SQG(NOEC & EC10) and the superseded EIL lie in the lower portion of the range of international As SQGs. The SQG(NOEC & EC10) for aged contamination, at 40 mg/kg, was twice the superseded interim urban EIL for As. The aged As SQG(LOEC & EC30) for urban residential/public open space soils lies in the upper part of the range of international SQGs while the aged As SQG(EC50) value for urban residential/public open space soils is markedly larger than any other international SQG.

Naphthalene does not biomagnify and has only a moderate potential to leach to groundwater. Therefore, only the direct toxicity exposure route was considered in deriving the SQGs. The minimum data requirements to use the SSD method were exceeded, there were no normalisation relationships, and there was no ageing/leaching factor. The toxicity data could only be expressed as total naphthalene concentrations. Therefore, moderate reliability generic (not soil-specific) naphthalene SQG(NOEC & EC10), SQG(LOEC & EC30) and SQG(EC50) values could be derived for:
    * fresh contamination
    * areas of ecological significance, urban residential/public open space and commercial/industrial land uses.
The generic naphthalene SQG(NOEC & EC10) values for soils with areas of ecological significance, urban residential/public open space and commercial/industrial land uses were 5, 70 and 150 mg/kg (total naphthalene) respectively. The SQG(LOEC & EC30) and SQG(EC50) values were approximately 22.5 and 5 times larger, respectively, than the corresponding SQG(NOEC & EC10) values. There is only a very limited number of international