Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p73
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 73/117)
Character Range: 553078–556294

sample from each relevant stratum (or per 1 m depth for thick units) for test pits, trenches and core from boreholes and additional samples from suspect spots should be submitted for laboratory analysis. The rationale for this sample size is discussed in Section 4.10 of Schedule B1.
Additional information on recommended practice for carrying out gravimetric analysis can be found in WA DoH (2009a) and the annual summary/update of the guidance document (WA DoH 2012) available from the WA DoH website:
http://www.public.health.wa.gov.au/3/1144/2/contaminated_sites.pm.

    12              Assessment of dioxins and dioxin-like compounds
Laboratory analysis for dioxins is only recommended when the site history clearly indicates that dioxins are likely to be present as a by-product resulting from specific manufacturing and industrial activities, or from waste disposal. Dioxin contamination may be present following long-term and large-scale use of a site for the following activities:
    * manufacture and waste disposal associated with certain chlorinated compounds, for example, PCBs, phenoxy herbicides, organochlorine pesticides, chlorinated benzenes, chlorinated aliphatic compounds, chlorinated catalysts, and halogenated diphenyl ethers
    * bleach pulp and paper mill processes known to produce dioxin
    * incineration of substantial chlorinated compounds
    * former municipal solid waste incinerators
    * hospital waste incinerators
    * extensive use of pentachlorophenol (PCP) in timber treatment.
Where dioxins are detected at levels significantly above background, a site-specific assessment will be required to determine the appropriate action (refer to Schedule B4 for further information).

Further background information on dioxins is provided in Appendix E.

    13              Data analysis

13.1          Data quality assessment
Prior to carrying out any processing or statistical analysis of the data set, an evaluation of the data quality should be carried out. As a minimum, this should include:
    * checks on the completeness of the data as specified in the DQOs (all sample locations, sample depths etc. reported)
    * checks on the accuracy of the reported data (all samples are correctly identified by location, depth, type etc.)
    * identification of any obviously anomalous results such as elevated levels that are unexpected given the CSM and field notes on sampling (indicating a possible labelling or laboratory error)
    * identification of invalid data (for example where the field or laboratory record indicates that sample integrity may have been compromised).
The possible reasons for anomalous data results (also see section 13.2.2) should be investigated and sampling and analysis repeated if appropriate.

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

13.2          Statistical analysis

    13.2.1      General
Detailed guidance on statistical procedures is beyond the scope of this guidance but some general considerations are outlined below. It is the responsibility of the site assessor to ensure that appropriate statistical procedures are followed when comparing site data with the investigation and screening levels listed in