Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:11:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 11 (pt 5/6)
Character Range: 1780861–1783736

data are considerably higher.

Nickel does not biomagnify so only the direct toxicity exposure route was considered in deriving the SQGs. Nickel, however, does have the potential to leach to groundwater. There was toxicity data for a total of 53 plant and animal species or soil microbial processes. In addition, there were normalisation relationships available for invertebrates, plants and soil microbial processes. A soil pH-modified ageing/leaching factor was available. The minimum data requirements to use the SSD method were exceeded, there were no normalisation relationships, and there was no ageing/leaching factor. Therefore high reliability soil-specific ACLs could be derived using NOEC and EC10, LOEC and EC30, and EC50 data for:
    * fresh contamination
    * aged contamination
    * areas of ecological significance, urban residential/public open space, and commercial/industrial land uses.
The soil-specific Ni ACLs based on NOEC and EC10 data for urban residential/public open space soils ranged from 10170 mg added Ni/kg for soils with a CEC ranging from 5 to 60 cmolc/kg. The corresponding ACL values for aged Ni contamination ranged from 15290 mg added Ni/kg. The ACL values based on LOEC and EC30 data and based on EC50 data were essentially identical and approximately 3 times larger than the NOEC and EC10-based ACL values. The range of international SQGs for Ni is 24500 mg/kg. Thus, only the urban residential/public open space ACLs for soils with a CEC above 40 cmolc/kg lie outside the range of internationally adopted SQGs. The superseded interim urban EIL for Ni was 60 mg/kg (total Ni). All of the SQGs would permit both lower and higher concentrations than the superseded interim urban EIL. In soils with a low Ni bioavailability, the maximum recommended concentration of Ni that can be added is 15 times the superseded interim urban EIL.

Trivalent chromium is an essential element for humans and animals but not for plants. It does not pose a potential environmental problem due to leaching (unless it is oxidised to hexavalent chromium), nor does it biomagnify. Toxicity data was available for a total of 21 invertebrate and plant species and soil microbial processes. There were only normalisation relationships available for earthworms. There was no ageing/leaching factor available for Cr (III). Therefore moderate reliability soil-specific ACLs could be derived using NOEC and EC10, LOEC and EC30, and EC50 data for:
    * fresh contamination
    * areas of ecological significance, urban residential/public open space and commercial/industrial land uses.
The  soil-specific Cr (III) ACL values based on NOEC and EC10 data for urban residential/ public open space land uses ranged from 3575 mg added Cr (III)/kg for soils with a clay content from 1 to greater than 10%. The ACL values based on LOEC and EC30 and based on EC50 data