Preliminary Site Investigations (PSI)

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

iEnvi provides environmental investigations at the desktop or initial stage of investigation including preliminary site investigations (PSI) and desktop environmental due diligence (EDD).

Being able to assess risk at this early stage of investigation is critical to ensuring significant contamination is not overlooked, and that reports are accepted by regulators and financial institutions. Our Certified Environmental Practitioners Site Contamination Specialists (CEnvP CS Specialists) are available to design and review our due diligence/PSI projects.

Contamination of properties can cause the property asset to have a negative value (or worse) and is often underestimated in terms of importance in decision making, negotiations, and liability risk. Depending on the project requirements and use of the PSI report, iEnvi may include a scope that is a desktop review only, or include limited sampling as part of the PSI.

Our clients often need these services for mergers and acquisitions (M&A), buying or selling properties, and for finance using a property as collateral.  The initial investigations can help determine the potential environmental liability at a property, which can help with financing, determination whether to do further contamination investigation, suitability of a site for a proposed use, and risk.

What is a Preliminary Site Investigation (PSI) and environmental due diligence, and when is it required?

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

We service the whole of Australia in providing PSIs for a wide range of industries and developments from our offices located in:

  • Brisbane, Queensland (QLD)
  • Sydney, New South Wales (NSW)
  • Melbourne, Victoria (VIC)

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).

Quick Enquiry

  • ✓ Valid number ✕ Invalid number
  • This field is for validation purposes and should be left unchanged.

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 (DSI)
Based on the outcomes of our PSI or evidence you have collected from the site our next stage is to conduct sampling on site (a detailed site investigation - DSI). A sampling, analysis and quality plan (SAQP) is developed to make sure we sample the right locations and depths, and test for targeted types of contamination. Sampling may include soil, groundwater, surface water, building materials, or gas/air. We test general or targeted locations, and will often try and determine if any contamination has migrated off your site.
3. Site remediation
Based on the results our field tests and the intended land use we progress from a Tier 1 up to Tier 3 risk assessment. If that indicates an unacceptable risk to human and ecological receptors, we develop a customised remediation action plan (RAP) which assesses remediation options and outlines the best fit for the project and how the remediation should be implmented. Where appropriate we will engage technical specialists and contractors 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!

Like to do this all online? At we offer four levels of environmental background investigation and reports reviewed by a Certified Environmental Professional in Australia’s first online shop. 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.

More details are located here:

Our daughter business – provides businesses and individuals a no-fuss, highly cost and time effective means of acquiring the environmental reports on what lies beneath the ground, without the hassle of dealing with consultant quotes, wait times and added expense.

Speak to us at [email protected] or try our online 2 minute PSI quotation portal if you prefer easy, quick no-nonsense payment and delivery.

Some of the organisations our expert team have helped

Comments are closed.