Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:9:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 9 (pt 2/4)
Character Range: 1114911–1117870

potentially exposed populations.
Interpretation of site data and selection of input data used in the risk modelling is paramount to the outcome of the risk assessment and requires professional judgement. In the selection of appropriate representative input data, the assessor should consider the CSM and make it clear how the input values and modelling strategy (for example, use of fate and transport models) relate to the CSM.

The risk assessment should also consider detection limits and their appropriateness in relation to the screening criteria and/or toxicity of a substance. The risk assessor should justify the reasoning behind the input values chosen for any risk assessment.

The report language should be objective and avoid the use of subjective terms such as 'heavy/medium/light contamination' which can lead to confusion. In many parts of the risk assessment, expert judgement is necessary. It should be made clear where this is the case, and all assumptions should be identified and explained.

Further information on what is required and what to include in the five-step process that comprises the fundamentals of the risk assessment are presented in the following sub-sections.

9.3.2          Issues identification
Issues identification should be part of the introductory section of the risk assessment. Information on the following should be provided:
    * the nature of the problem (i.e. why this assessment is being carried out)
    * the stakeholders (including off-site receptors where relevant) and their objectives (as far as possible)
    * the objectives of the risk assessment (what the risk assessment is trying to determine)
    * an outline of the risk management decisions that need to be made.
The relationship between the risk assessment and the risk management process should be made clear.

9.3.3          Data collection and evaluation (development of a conceptual site model)
The data collection section relies on a well-designed site assessment developed with an understanding of potential exposure pathways/routes associated with past and present land use in mind. It is assumed here that the site investigation itself is presented as a separate document (or report section) which need not be repeated in the risk assessment though the raw data relied on in the risk assessment should be included as an appendix.

The data collection section should include the following:
    * identification of the data used in the risk assessment
    * consideration of the data quality objectives and whether these are met by the data available
    * identification of any significant data gaps.
The data evaluation section should include:
    * summary of 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)