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 1/2)
Character Range: 1533534–1536397

20                     60

For aged contaminated sites (i.e. the contamination has been in place for at least two years, see Schedule B5b) the methodology recommends using the 25th percentiles of the ABC data for the 'old suburbs' of Olszowy et al. (1995) (see Table 14). The ABC values for Zn in 'new suburbs' were similar to the values predicted by the Hamon et al. (2004) method. Therefore it is recommended that the Hamon et al. (2004) method be used to generate ABC values for new suburbs (that is, <2 years old) as soil-specific values will be generated, while for old suburbs with aged contamination (that is, >2 years) it was recommended that the 25th percentile of the ABC data from old suburbs (Olszowy et al. 1995) be used.
Table 14. Zinc (Zn) ABC based on the 25th percentiles of Zn concentrations in 'old suburbs' (i.e. >2 years old) from various states of Australia (Olszowy et al. 1995).
Suburb type               25th percentile of Zn ABC values (mg/kg)
                          NSW                                       QLD  SA  VIC

New suburb, low traffic   25                                        15   25  15
New suburb, high traffic  45                                        30   30  20
Old suburb, low traffic   75                                        80   55  40
Old suburb, high traffic  120                                       160  90  55

3.6.1.3         Examples of soil quality guidelines for fresh zinc contamination based on no observed effect concentration and 10% effect concentration data
To calculate an SQG(NOEC & EC10), the ABC value is added to the ACL(NOEC & EC10). ABC values vary with soil type. Therefore, it is not possible to present a single set of SQG(NOEC & EC10) values. Thus, two examples of SQG(NOEC & EC10) values for urban contaminated soils are provided below. These examples would be at the low and high end of the range of SQGs values (but not the extreme values) generated for Australian soils.

Example 1
Site descriptors  urban residential/public open space land use in a new suburb.
Soil descriptors – a sandy acidic soil (pH 5, CEC 10) with a 1% iron content.
The resulting ACL(NOEC & EC10), ABC and SQG(NOEC & EC10) values are:
ACL(NOEC & EC10):   45 mg/kg
ABC:     10 mg/kg
SQG(NOEC & EC10):   55 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 a 10% iron content.
The resulting ACL(NOEC & EC10), ABC and SQG(NOEC & EC10) values are:
ACL(NOEC & EC10):   480 mg/kg[1]
ABC:    40 mg/kg
SQG(NOEC & EC10):   520 mg/kg

3.6.2         Calculation of soil quality guidelines based on protecting aquatic ecosystems from leaching of fresh zinc contamination
As indicated in the exposure pathway assessment, the log Kd values for Zn measured in a range of Australian soils were below 3 and therefore