Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:9:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 9 (pt 3/4)
Character Range: 1117598–1120678

the CSM
    * selection of and justification for Tier 1 screening criteria
    * explanation of any fate and transport modelling used (e.g. groundwater fate and transport to estimate groundwater quality at an off-site receptor for comparison with drinking water standards)
    * identification of any need for site zoning to consider specific source areas separately (e.g. hotspots, or areas where different land uses apply)
    * explanation of the basis on which the site results are screened (e.g. comparison of 95% UCL of each zone to the screening criteria)
    * Tier 1 screening
    * identification of and justification for contaminants of concern for Tier 2 assessment
    * identification of critical exposed populations (including off-site receptors where relevant) and pathways for Tier 2 assessment
    * identification of and justification for any insignificant exceedences of screening criteria that will not be assessed at Tier 2.

9.3.4          Exposure assessment
This section should include a clear discussion on the exposure scenarios likely to occur at the site, and whether the site-specific situation fits into the exposure scenarios characterised in Schedule B7. If these scenarios are not applicable or representative of the exposure scenario under assessment, an explanation together with behavioural and lifestyle assumptions and site assumptions should be provided within the report.

Software and mathematical algorithms used to calculate the contaminant intake should be referenced. It is only necessary to present equations if the risk assessment uses a method that is not published in full (for example, if amendments to algorithms are made). An explanation of why the model or approach selected is appropriate should be given.

All input variables should be presented and justified. Use of default assumptions should be justified.

All reasonable efforts should be employed to validate exposure models (model uncertainty) with field data (for example, soil vapour data to inform outputs from the model developed by Johnson and Ettinger (US EPA 2004a)) where possible.

9.3.5          Toxicity assessment
In the hazard identification, a brief summary of the potential adverse effects of the contaminants of concern should be given. The summary should concentrate on the potential effects that are relevant to the contaminant in the context of the site and the exposure scenarios. Lengthy reviews of toxicology are not generally required. Clear presentation and referencing for physical and chemical properties is also required.

Doseresponse assessment involves selection of appropriate toxicity reference values. If toxicity reference values used are adopted from the relevant Schedule B7 appendix, then no additional explanation is required and a reference is sufficient. If toxicity reference values are selected for substances not included in Schedule B7, then explanation and justification of a similar order to that presented in Schedule B7 should be given.

9.3.6          Risk characterisation

9.3.6.1         Overview
This section needs