Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 3/8)
Character Range: 102923–105962

relevant should be considered in the data analysis. The data should be evaluated for trends and the presence of hot spots prior to the application of any biodegradation factors.

    3.2.2          Exceedence of Tier 1 investigation and screening levels
The magnitude of the exceedence should be considered in the context of the CSM (that is, whether the exposure pathways are plausible and whether exposure will result in harm). In cases of minor exceedence of investigation or screening levels, a qualitative risk assessment may be sufficient to evaluate the potential impact.

Where exceedence of Tier 1 investigation and screening levels indicates that there is a likelihood of an adverse impact on human health or ecological values for that site, site-specific health and/or ecological risk assessment (Tier 2 or 3) should be carried out as appropriate. This will usually require the collection of additional site data.

Alternatively, appropriate management options may be considered such as engaging with landowners and occupants/site users regarding the nature of the contamination and implementing appropriate site management plans. Guidance on community engagement and risk communication is provided in Schedule B8.

The nature of the response should be determined on a site-specific basis and be proportional to the potential risk posed to human health and/or the environment.

    3.2.3          Procedure if no generic investigation or screening levels are available
Site-specific investigation levels will need to be developed when:
    * investigation or screening values are not available for the contaminants of concern and/or insufficient data is available for the derivation of generic guideline values
    * site conditions, receptors and/or exposure pathways differ significantly from those assumed in the derivation of the generic investigation or screening levels.
Consult Schedules B4 and B7 for guidance on deriving site-specific HILs and on applying the HIL methodology to derive HILs for additional substances.

Consult Schedule B5b for guidance on applying the EIL methodology to derive EILs for additional substances. Schedule B5b Appendix B provides guidance using a method of soilwater partitioning coefficients for deriving EILs that are protective of aquatic ecosystems.

3.3              Specific considerations for  petroleum hydrocarbons
The flowchart in Figure 1 (below) provides a general overview of the application of the HSLs and ESLs for petroleum hydrocarbons including linkage to the 'management limits' for TPH contamination. Information on these screening levels can be found in:
Human health concerns
    * HSLs check list – ASC NEPM Toolbox
    * Vapour inhalation pathway – HSLs – Section 2.4
    * Direct contact pathways – HSLs – Section 2.4
    * Consumption of groundwater – GILs – Section 2.8 and Schedule B6
    * HILs – Benzo(a)pyrene, total PAH and lead – Section 2.2 and Schedule B7
    * Aesthetics – Section 3.6
    * 'Management limits' – Section 2.9.
Ecological concerns
    *