Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:20:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 20 (pt 1/7)
Character Range: 1691238–1693908

20              30

8.6.1.3         Examples of soil quality guidelines for fresh lead contamination in Australian soils based on no observed effect concentration and 10% effect concentration data
The ABC values for Pb vary with the iron content of the soil. Therefore, it is not possible to present a specific set of SQGs(NOEC & EC10), but rather two examples of the range of SQGs that will be encountered in urban settings are presented.
Example 1
Site descriptors  urban residential land/public open space use in a new suburb (i.e. fresh contamination).
Soil descriptors – a sandy acidic soil (pH 5, CEC 10) with 1% iron content.
The resulting ACL(NOEC & EC10), ABC and SQG(NOEC & EC10) values are:
ACL(NOEC & EC10):   130 mg/kg
ABC:     1 mg/kg
SQG(NOEC & EC10):   131 mg/kg, which would be rounded off to 130 mg/kg.

Example 2
Site descriptors  commercial/industrial land use in a new suburb.
Soil descriptors – an alkaline clay soil (pH 7.5, CEC 40) with 10% iron content.
The resulting ACL(NOEC & EC10), ABC and SQG(NOEC & EC10) values are:
ACL(NOEC & EC10):   220 mg/kg
ABC:    15 mg/kg
SQG(NOEC & EC10):   235 mg/kg, which would be rounded off to 230 mg/kg.

8.6.2         Calculation of soil quality guidelines for fresh lead contamination based on LOEC and 30% effect concentration toxicity data and on 50% effect concentration data

8.6.2.1         Calculation of soil-specific added contaminant limits
ACLs based on LOEC and EC30 toxicity data (ACL(LOEC & EC30)) and based on EC50 data (ACL(EC50)) were calculated using the method used to derive the ACL values based on NOEC and EC10 data, the one exception being that in order to maximise the amount of LOEC and EC30 and EC50 data, actual measured NOEC data was used to estimate LOEC, EC30 and EC50 data. This was done using the conversion factors derived by Heemsbergen et al. (2008) and presented in Table 17. The geometric means of the LOEC and EC30 data and of the EC50 data for the various species/microbial processes that were used to derive the ACL(LOEC & EC30) and  ACL(EC50) are presented in Table 62.

The resulting ACL(LOEC & EC30) and ACL(EC50) values for the three land uses are presented in Table 65. As expected, these values are larger than the corresponding ACL(NOEC & EC10) values. The ACL(EC50) values are also generally larger than the ACL(LOEC & EC30) values, with the exception of the values for areas of ecological significance. This occurs because the slope of the SSD for the LOEC and EC30 data is less than that of the EC50 data, the SSDs intersect and the LOEC and EC30 data ends up having larger toxicity values.
Table 65. Generic ACLs (mg/kg) based on LOEC and 30% effect