Common Instructions

These are the terms and instructions clients, councils and legal teams commonly use for this work in Australian practice.

• Preliminary Site Investigation
• PSI report
• Preliminary site investigation report
• Phase 1 ESA Australia

Reviewer

Reviewed by Michael Nicholls, Principal Environmental Scientist (CEnvP #0831, Site Contamination Specialist SC40037).

Last reviewed 24 May 2026.

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Primary Sources

These official references commonly inform the way this work is scoped, interpreted or defended.

• ASC NEPM
• NSW EPA contaminated land guidelines

Contaminated land due diligence

Preliminary site investigations that clarify contamination risk early.

iEnvi prepares preliminary site investigations for acquisition, planning, redevelopment and broader due diligence where the first question is whether contamination is likely, material and decision-relevant.

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Typical matters

Typical matters

• Property transactions, site acquisition and refinancing.
• Development applications and early planning-stage contamination review.
• Sites with historical industrial, commercial or fill-related land use risk.

Scope of advice

Scope of advice

• Desktop review, site history assessment and conceptual site model development.
• Site reconnaissance and targeted advice on whether intrusive investigation is warranted.
• Clear reporting on likely risks, data gaps and recommended next steps.

How we work

How we work

• Focus on the commercial and regulatory significance of the likely contamination issues.
• Senior contaminated land judgement available where the matter needs it.
• A practical first-step report rather than a generic template exercise.

Related projects

Selected project summaries.

These published project summaries provide practical examples of adjacent site issues and service delivery.

Project summary

Preliminary Site Investigations for Potential Acquisition, VIC and WA

Two coatings manufacturing sites in Victoria and Western Australia were assessed by iEnvi through preliminary site investigations (PSI) to identify contamination risks, regulatory implications…

Read project summary

Project summary

From Quarterly to Biannual: Groundwater Monitoring that Keeps Risk Low

Practical groundwater monitoring that confirms monitored natural attenuation, meets regulator expectations, and supports a safe transition from quarterly to biannual sampling with clear triggers…

Read project summary

Project summary

Preliminary Site Investigation – Abbotsford Residential Development

iEnvi completed a desk-based Preliminary Site Investigation (PSI) for a proposed residential development in Abbotsford, VIC. The PSI found a low risk of contamination…

Read project summary

Related pages

Further reading and related service pages.

Detailed Site Investigations

Learn more

Contaminated Land

Learn more

Property and Development Services

Learn more

Need advice on this issue?

Contact iEnvi on 13000 43 684 or email info@ienvi.com.au to discuss the site, timing and available information.

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Common Questions

What is included in a Preliminary Site Investigation?

A PSI typically includes a review of site history using aerial photographs, historical records, and government databases; a search of contaminated land registers (EMR/CLR in Queensland, EPA records in other states); an assessment of surrounding land use and potential off-site sources; a site walkover to observe current conditions; and a report with a conceptual site model and recommendations on whether further investigation is needed.

How long does a PSI take to complete?

A standard PSI for a residential or commercial property can usually be completed within 1–2 weeks from instruction, depending on the availability of historical records and site access. More complex sites with extensive industrial history or multiple lots may take longer. We provide a clear timeline at proposal stage.

Is a PSI enough to satisfy council requirements?

It depends on the findings. If the PSI concludes that the site has a low risk of contamination and no further investigation is warranted, council will often accept this as sufficient. If the PSI identifies potential contamination sources or data gaps, council will typically require a Detailed Site Investigation (DSI) before approving the development application. The PSI report will clearly state the recommended next steps.