Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p10
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 10/117)
Character Range: 372892–376231

dispatcher, courier and laboratory) should complete the chain-of-custody documentation so that it gains the status of a valid record of sample transfer to the laboratory. An example of a chain-of-custody form can be found in NSW EPA (1994).

The assessment report should include a copy of the receiving laboratory's advice with respect to:
    * the condition in which the samples and chain-of-custody documentation were received and the container type
    * cross-checking information on sample identification numbers and paperwork received
    * confirmation of preservation method.

5.5              Choice of analytes
Analyte choice should be informed by the site history findings and data gaps identified in the development of the CSM and the DQO process. Depending on the available history, potentially contaminated fill may require a more extensive suite of analytes. The appearance and odour of soil and groundwater samples may influence the selection of analytes.

Appendix A provides a list of possible analytes by contaminant grouping. Specific information on the assessment of asbestos and dioxins can be found later in this Schedule.

Additional information on the selection of possible analytes is available in the Standard guide to the investigation and sampling of sites with potentially contaminated soil (AS 4482.1-2005), WA DoE (2004), and Turczynowicz (1991).

5.6              Data quality assessment
Checking the validity and usability of the data collected assists with ensuring that only representative and reliable data meeting the specified requirements is considered in the assessment. Activities include verification of sampling procedures, data verification and validation and determination of data usability. The principal assessment measures (also known as Data Quality Indicators or DQIs) are precision, accuracy or bias, representativeness, completeness and comparability.

Further information is provided in Section 13.1, Appendix C and US EPA (2006a).

    6                   Sampling Design

6.1              Introduction
The site assessor should exercise professional judgement to select and develop an appropriate sampling design, based on accurate and reliable site-specific information (as integrated in the CSM) as far as practicable to obtain sufficient representative data to address the DQOs. For example, if the objective is to establish whether a site is contaminated, a limited number of samples located in those areas most likely to be contaminated may be sufficient, however, a greater number of samples and effort would be required to delineate known contamination. An explanation of, and justification for, the sampling design selected should be provided in the assessment report.

6.2              Categories of sampling designs
Source: US EPA (2002)
There are two main categories of sampling design: judgemental and probability-based sampling programs. The advantages and disadvantages of judgemental and probability-based sampling are listed in Table 2.
Table 2. Advantages and disadvantages of probability-based and judgemental sampling
               Probability-based                                                              Judgemental
Advantages         * Designs are unbiased                                                         * Can be less expensive than probabilistic