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    Investigating and testing


If you want to investigate your land further, or if your land is on the LLUR and you want to know whether it is contaminated you must engage a suitably qualified and experienced practitioner (SQEP). They will undertake a Preliminary Site Investigation (PSI) that will show whether the land needs further investigation through Detailed Site Investigation(DSI).

 A preliminary site investigation (PSI) is often referred to as a desktop study because it doesn’t usually involve sampling and analysis of the soil. The main objectives of a PSI are to gather information about a piece of land to determine whether it may potentially be contaminated, to assess the suitability of the land for its current or intended land use, and to design a detailed site investigation (if required).This link provides more information about a detailed site investigation.

The National Environmental Standard requires that any investigations are undertaken and signed off by a SQEP. This is someone who is independent, applies good professional practice and reports against appropriate contaminated land and industry guidelines. A Detailed Site Investigation should be signed by a suitably qualified experienced practitioner. They will certify that the report complies with good practice and professional standards and that the practitioner stands by the conclusions of the report.

The expected minimum qualifications for a suitably qualified practitioner are:

  • Senior or principal scientist/engineer
  • Relevant tertiary education
  • At least 10 years of contaminated land experience.

Every person involved in the Detailed Site Investigation and subsequent report preparation does not necessarily have to meet all these minimum qualifications but the person certifying the report on behalf of their company would be expected to meet them.

To select a suitably qualified and experienced practitioner (SQEP), consult the Environmental Consultants listings in the Yellow Pages or online. You should seek comparative quotes from different practitioners before engaging a consultant.

Ideally the certifier would belong to a recognised professional body that assesses and certifies environmental professionals in the competency criteria of training, experience, professional conduct and ethical behaviour – membership of an industry association alone does not qualify. Professional bodies include:


Undertaking investigations is a staged process and is carried out in accordance with government guidelines.

A Detailed Site Investigation report should:

  • Assess the area, extent and nature of soil contamination at the site.
  • Evaluate whether soil contaminant concentrations exceed human health standards and guideline values established in the National Environmental Standard (NES) and other sources.
  • Identify and assess potential risks from identified contaminants to public health and the environment.

You can find out more about the process here and on the following site.

The following link provides useful information from the Western Australian (WA) Department of Health (DOH) for the investigation, remediation and management of asbestos-contaminated sites, and it is based on both Australian and international best practices. Click here for more information.


Investigation costs vary.  They can depend on the size of your site, the current and previous land uses and the hazardous substances that might be present. 

You need to ask the specialist practitioner for an estimate of costs. We recommend seeking and comparing quotes from different practitioners.

If a site investigation finds that the concentration of hazardous substances poses a risk to human health or the environment, you may need to remediate or manage your site. Your SQEP will be able to provide you with additional advice about the next steps for you to take.