Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p15
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 15/117)
Character Range: 387368–391006

a specific area, sampling points are located relative to the suspected source(s) using judgemental sampling stepping out from the suspected source location, or systematic grid sampling centred on that location.

Specialised professional advice should be sought in developing sampling plans for rock soil mixtures at waste rock dumps, tailings dams, heap leach pads, and other artificial structures associated with mining site contamination.

Table 3 presents examples of example investigation scenarios that may be encountered and suggests sample designs that may be relevant. As indicated below, a more sophisticated sampling design may follow on from a preliminary (screening) investigation.
Table 3. Selecting an appropriate sampling design
If you are…                                                                                                and there is…                                            consider using…                           in order to…
performing a relatively small scale  screening investigation                                               limited budget and/or schedule                           judgemental sampling                      assess whether further investigation is warranted
developing an understanding of where contamination is present                                              adequate budget for the number of samples needed         grid sampling                             acquire coverage of the area of concern with a given level of confidence that a hotspot of a given size would be detected
estimating a population mean                                                                               adequate budget for the number of samples needed         systematic or grid sampling               produce information on spatial or temporal patterns
developing a detailed understanding of where contamination is present and/or estimating a population mean  spatial or temporal information on contaminant patterns  stratified sampling                       increase the precision of the estimate in key areas of concern
                                                                                                                                                                    (includes judgemental and grid sampling)

Adapted from US EPA 2002

6.4              Sampling density and depth of sampling
The aims of an SAQP (refer Section 5.3) are to reduce the likelihood of under assessment (that could result in significant adverse effects from unidentified contamination) or over assessment (concluding that a site requires further investigation when in reality it does not) and to enable an appropriate level of remediation of contamination that is sufficient to protect human health and the environment.

The information presented in this section can be applied to both horizontal and vertical sampling.

Consideration of the CSM and DQOs should inform the requirements for sampling density and depth of sampling. The amount of sampling required will depend on an integrated appraisal of factors including:
    * the size of contaminated areas to be detected
    * the number of stages of sampling considered feasible
    * the size of the site and final subdivided lots if the site is to be subdivided
    * the distribution of uses on the site and the disposition of structures
    * the site history (which may vary across the site).
When developing a sampling program, consideration should be given to numerous factors including, but not limited to:
    * the likely heterogeneity of any surface fill and underlying geological units
    * whether knowledge of background