Preliminary Site Investigations (PSI)

Preliminary Site Investigations (PSI) visual inspection
Preliminary Site Investigations (PSI) visual inspection

What is a Preliminary Site Investigation (PSI) and when is one required?

A PSI is essentially the first step in investigating risk associated with contamination under Australia’s national environmental guidelines.

Not every property requires a Preliminary Site Investigation (PSI), but yours might. The purpose of a PSI is to assess the potential for contamination of a site.

Typical triggers of a PSI include:

  • As part of your due diligence before you buy or sell a property, often required by financiers;
  • Your development application or planning permit may include a PSI as a council requirement;
  • Immediately preceding an application for change of land use;
  • Before an excavation of the subsurface;
  • Part of mergers and acquisitions processes, for the portfolios of properties;
  • Part of establishing a baseline of contamination conditions prior to lease or sale; and
  • Part of your lease conditions.

Your Preliminary Site Investigation will begin with a review of your property’s history. This is completed by the investigator off-site using historical government databases, historical aerial photographs, geological, groundwater, reports and other documents, planning drawings, and other available records. It is often referred to as a “desktop study”.

In addition, you can choose to have a site inspection conducted, where the investigator may need to ask some questions of everyone concerned, and walkover the property to make observations – this will take longer for industrial properties. Sometimes soil samples are taken during the PSI. This will depend on the nature of the reason you require a PSI, and the potential for contamination for the property. It is more cost effective to include soil sampling during the PSI, and this further reduces the risk substantially and increases certainty for potential purchasers.

Then you get your report. If your site has potential for contamination, the report will explain what the chemical contaminants are and where, and how this may be a concern for the current and future planned use of the property. The report will also explain what steps need to be taken next to investigate further. This is simply a preliminary report, but it is very detailed.

It is possible to “pass” a PSI, and have a property cleared as having a low risk of contamination and low contamination risk to people and the environment. Sometimes further investigation is not required.

The objective of the PSIs to help determine the potential for risk to human health and the environment from both current and historical, onsite and offsite land contamination.

Our overall approach to contamination and suspected contamination

Our approach has three main phases, each leading when neccessary to the next. Our aim is to control your costs through progressive elimination of risks and through knowledge acquired. Our approach enables you to have a good understanding of your suspected or confirmed contaminations and to enable you to effectively manage your site now and into the future. While the steps are common across remediation for many contaminants, our wide experience with individual contaminants allows us to deliver a timely cost effective solutions where you are in control of the process (and budget).
1. Preliminary site investigation
This is a paper based study that investigates the known history of the site, including its use and can provide good evidence on the the scale (if any ) of the contamination. We also look to the neighbouring geography to look for cross contamination. For many clients looking to cover their bases this might be as far as you need to go. If you need to go further it is an effective tool in fine tuning your onsite testing to reduce time and cost required.
2. On site testing
Based on the outcomes of our PSI or evidence you have collected from the site our next stage is to conduct field testing on site. The sample includes any zones of particular interest together with boundary samples or anything our modelling of water or land shifting suggests. Our tests are dependant on your intended land use in the future and can include top layer as well as bore samples. These build an effective evidence portfolio going forward
3. Site remediation
Based on the results our field tests and the intended land use we develop if needed a customised remediation plan including removal, capping layer(s) and vegetation solutions. Where appropriate we will engage soil, geotechnical and earth moving specialists that we know and have used for many years and take care of all the management of the entire project, with regular reporting to you!.
online environmental report
Onsite or online...its up to you!

PSI Options

We offer four levels of environmental background investigation and reports reviewed by a Certified Environmental Professional. You can choose what you need quickly for the best price and fastest delivery. The options are:

  1. Environmental desktop records and summary letter
  2. Desktop Preliminary Site Investigation (PSI), not including a consultant site visit.
  3. Preliminary Site Investigation (PSI), including a consultant site visit, without soil sampling.
  4. Preliminary Site Investigation (PSI), including a consultant site visit, with soil sampling and laboratory analysis of a comprehensive standard suite of contaminants.