Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 2/3)
Character Range: 1739882–1742572

suburb, with high traffic volume.
Soil descriptors  an alkaline clay soil (pH 7.5, CEC 40) with 10% iron content.
The resulting ACL(EC50), ABC and SQG(EC50) values are:
ACL(EC50):    1200 mg/kg
ABC:    10 mg/kg
SQG(EC50):    1210 mg/kg, which would be rounded off to 1200 mg/kg.

9.8              Reliability of the soil quality guidelines
The SQGs for Ni were considered to be of high reliability, as the toxicity data set met the minimum data requirements to use an SSD method and there were normalisation relationships available to account for soil characteristics (Schedule B5b).

9.9              Comparison with other guidelines
Soil quality guidelines for Ni in a number of international jurisdictions are presented in Table 82. These SQGs have a variety of purposes and levels of protection and therefore a comparison of the values is problematic. The SQGs for Ni range from 24 to 500 mg/kg added and total Ni, with both of these values coming from countries within the EU. The superseded interim urban EIL for Ni (NEPC 1999) was 60 mg/kg total Ni.

There are also four health-based investigation level (HIL) values that range from 400 to 4000 mg/kg total Ni (see Schedule B1). The urban residential/public open space ACLs based on NOEC and EC10, LOEC and EC30, and EC50 data for fresh Ni contamination range from 10–170, 10–170, and 30 to 520 mg/kg added Ni respectively. These correspond to the 'minimal risk', 'warning risk' and the 'potential risk' values of EU member countries and the values are very similar. The urban residential/public open space ACLs based on NOEC and EC10, LOEC and EC30, and EC50 data for aged Ni contamination range from 15290, 30560, and 55910 mg/kg added Ni respectively. These limits permit higher concentrations than in any of the other jurisdictions, but this is not suprising as the other jurisdictions do not account for ageing or leaching, nor do they take into account the bioavailability in different soils.

The most meaningful comparisons can be made between the SQGs and the concentrations that would protect 95% of species based on NOEC and EC10 data that was derived in the EU ecological risk assessment for Ni (EC 2008b). These values ranged from 8.3 to 188.7 mg/kg added Ni for soils with CEC values ranging from 2.4 to 36 cmolc/kg (EC 2008b). SQGs that protected 95% of species were not derived, but rather the SQGs were derived that protect 99, 80 and 60% of species. The SQGs that aim to protect 99% of species based on NOEC and EC10 data ranged from 120 mg/kg added Ni. The SQGs that aim to protect 80% of species based on NOEC and EC10 data ranged from 10170mg/kg added Ni. These comparisons indicate that the SQGs derived