Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:20:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 20 (pt 3/7)
Character Range: 1696353–1699382

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(EC50), ABC and SQG(EC50) values are:
ACL(EC50):    890 mg/kg
ABC:    15 mg/kg
SQG(EC50):    905 mg/kg, which would be rounded off to 900 mg/kg.

8.7              Calculation of soil quality guidelines for aged lead contamination

8.7.1         Calculation of an ageing and leaching factor
Smolders et al. (2009) examined the literature and developed ALFs for Pb for a range of different organisms. The resulting ALFs ranged from 1.1 to 43 with a median of 4.2. The value of 4.2, recommended by Smolders et al. (2009), was adopted and used in the EU ecological risk assessment of Pb (LDA 2008). Leaching factors for Pb have been developed for five Australian soils from South Australia, which ranged from 0.92 to 2.98 and a median and geometric mean of 1.66 and 1.61 respectively (Stevens et al. 2003).

Given the values of Stevens et al. (2003) only account for leaching and not ageing, it is likely any ALFs for Australian soils would be larger and therefore are likely to be consistent with the ALF of Smolders et al. (2009). An ALF of 4.2 was adopted in this project to calculate the SQGs for aged Pb contamination.

8.7.2         Calculation of soil quality guidelines for aged lead contamination based on NOEC and 10% effect concentration toxicity data

8.7.2.1         Calculation of soil-specific added contaminant limits
The ACL values for aged contamination were calculated in exactly the same manner as those for fresh contamination except that the NOEC and EC10 toxicity data was corrected using the Smolders et al. (2009) ALF of 4.2. The resulting ACL values are presented in Table 66.
Table 66. Generic ACLs (mg/kg) based on NOEC data and 10% effect concentration data (EC10) for aged lead (Pb) contamination in soil with various land uses.
Land use                             ACL(NOEC & EC10)
                                     (mg/kg)
Areas of ecological significance     170
Urban residential/public open space  530
Commercial/industrial                940

8.7.2.2         Calculation of ambient background concentration values
For aged contaminated sites (that is, the contamination has been in place for at least 2 years), the methodology (Schedule B5b) recommends using the 25th percentiles of the ABC data for the 'old suburbs' from Olszowy et al. (1995) (see Table 67).
Table 67: Lead (Pb) ABCs based on the 25th percentiles of Pb concentrations in 'old suburbs' (i.e. >2 years old) from various states of Australia (Olszowy et al. 1995).
Suburb type               25th percentile of Pb ABC values (mg/kg)
NSW                       QLD                                       SA   VIC
Old suburb, low traffic   100                                       30   30   35
Old suburb, high traffic  160                                       150  90   70

8.7.2.3         Examples of soil quality guidelines for aged lead contamination in Australian soils based