Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 3/5)
Character Range: 1604047–1607178

a minor effect on the resulting SQG(NOEC & EC10) (i.e. the PC80 for all species was 68 mg/kg while the corresponding value when the vertebrates were removed was 60 mg/kg).
Figure 5. The species sensitivity distribution (plotted as a cumulative frequency of the toxicity data against naphthalene soil concentration) of soil invertebrates, plants and terrestrial vertebrates to naphthalene.

5.6              Calculation of soil quality guidelines for fresh naphthalene contamination
Given that (a) there was sufficient toxicity data to use the BurrliOZ software, (b) the data could not be normalised to the Australian reference soil, and (c) the toxicity data could not be expressed in terms of added concentrations, it meant that there was a single output from the BurrliOZ SSD for each of the three land uses (that is, areas of ecological significance, urban residential/public open space, and commercial/industrial). Therefore, the output from the SSD was a single generic (not soil-specific) SQG for each land use.

5.6.1         Calculation of soil quality guidelines for fresh naphthalene contamination based on no observed effect concentration and 10% effect concentration toxicity data
The generic SQGs for naphthalene in soils with each of the three land uses are presented in Table 39.

Table 39. Generic soil quality guidelines for naphthalene in freshly contaminated soils with different land uses based on no observed effect concentration and 10% effect concentration toxicity data.
Land use                             SQG(NOEC & EC10)
                                     (mg/kg total naphthalene)
Areas of ecological significance     5
Urban residential/public open space  70
Commercial/industrial                150

5.6.1.1         Calculation of ambient background concentration values
There is no equation available to estimate the background concentration of naphthalene. Naphthalene is produced by some organisms (for example, magnolias and termites) but at very low concentrations, which are negligible in terms of ABC values. Naphthalene can also be synthesised as a result of fires and in fire-prone areas and it might be appropriate to determine naphthalene ABC values.

In most soils, naturally occurring naphthalene concentrations will be negligible. For the purpose of this guideline the ABC for naphthalene was assumed to be 0 mg/kg. Therefore, the reported toxicity values which were expressed as total naphthalene were identical to the data when expressed as added naphthalene concentrations (that is, total concentration – 0 = added concentration) and therefore the ACLs derived using the SSD methodology equalled the SQGs.

It should be noted that if a soil-specific ABC for naphthalene is determined then that could be added to the above values to obtain a soil-specific SQG. Otherwise, these generic SQGs are applicable to all Australian soils with these particular land uses.

5.6.2         Calculation of soil quality guidelines for fresh naphthalene contamination based on lowest observed effect concentration and 30% effect concentration data, and based on 50% effect concentration toxicity