Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 3/6)
Character Range: 1181710–1184654

work identifies both the extent and degree of on-site contamination and the contaminants of concern. At this point in the ERA framework, contaminants of concern are those chemicals that have concentrations above the background concentrations or those that may have concentrations above the background based on the site history.

The selection of the most appropriate EILs to apply for the contaminants of concern is dependent on whether soil-specific EILs are available for the appropriate land uses(s). If soil-specific EILs are available, then the decision should be based on the physicochemical properties of the soil at the site. Otherwise, the selection will be based on land use.  Schedule B1 provides examples on the application of EILs.

4.2              Receptor identification
In a Preliminary ERA, it is assumed that all biota and supporting ecological processes that are of ecological value to the land use (that is, areas of high ecological value, urban residential and open public space, commercial and industrial) are of ecological value to the site. However, where a particular species (for example, giant Gippsland earthworm) or type of organism (for example, soil microbial processes) that is an important part of the ecological value[2] at a site was not considered in the derivation of the most appropriate EILs (see Section 5.5), the EIL may not provide adequate protection and a Definitive ERA should be undertaken. The basis for such a decision should be clearly presented in the Preliminary ERA report.

4.3              Exposure assessment
In a Preliminary ERA, it is assumed that all exposure pathways considered in the derivation of the EILs are applicable. The physical setting of the site significantly influences exposure, since features such as soil type, soil organic matter content, paving and buildings can impact upon exposure pathways and contaminant availability. Exposure is also influenced by physical and chemical properties of the contaminants (for example, solubility in water, n-octanol/water partition coefficient (Kow), soil/water partition coefficient and volatility). Each of these parameters may be evaluated to take account of site conditions, therefore providing a more site-specific estimate of the amount of a chemical an organism or a population may receive. If the results of the above analysis indicate that exposure pathways that are thought to be significant have not been considered, or that the magnitude of an exposure pathway is suspected to be underestimated in the derivation of EILs, a Definitive ERA should be undertaken. The basis for a decision to proceed or not to a Definitive ERA should be clearly presented with justifications in the Preliminary ERA report.

4.4              Toxicity assessment
In a Preliminary ERA, it is assumed that the toxicity data and methods used to calculate the endorsed EILs are sufficiently protective of the general ecological system and biota