Environmental due diligence is the process of evaluating a property, asset or business before a transaction, so the buyer can understand and manage the risks and obligations that come with it. The risk it’s there to catch is a serious one: that the site you buy carries a contamination liability worth hundreds of thousands of dollars or more. In the worst cases, the cost of cleaning up the contamination is greater than the property itself is worth.
A due diligence assessment puts a number on that risk before you’re locked in. It lets you factor clean-up into the price, negotiate with the vendor, or decide the risk is more than you want to take on.
What an environmental due diligence assessment covers
An environmental site assessment is a study of the past and present activities on a site, so we can judge the likelihood of contamination and what it would mean for human health and the environment. The scope varies with the site and the level of detail you need, but in general it includes:
- a review of the current condition and history of the site
- a soil (and where needed, groundwater) investigation program designed for the site
- assessing the source, type, extent and level of any contamination present
- determining the risk that contamination poses to human health and the environment
- determining whether the land is suitable for its proposed future use
- recommendations for remediation or management, if any is needed.
The assessment is usually run in two phases, and culminates in a report you can act on, and put in front of a council, a regulator or the other side of a transaction.
Phase 1 and Phase 2
- **Phase 1** is a preliminary assessment: a desktop review of the site’s history and records, plus a site inspection, to work out whether contamination is likely and where. Many sites need nothing more than this.
- **Phase 2** takes the Phase 1 findings further, with sampling and laboratory testing of soil, and groundwater in some cases, to confirm what’s actually present and how much.
Airsafe carries out environmental site assessments in line with state and territory legislation and policies, Australian standards and EPA guidelines, and to the assessment framework in the National Environment Protection (Assessment of Site Contamination) Measure. For the full four-stage investigation and validation process, see our Contaminated Land Assessments page.
When you need one
An environmental site assessment is often part of regulatory compliance. The EPA or your local council may require one for a rezoning or redevelopment, or for a property purchase or divestment, due diligence, or a commercial liability clean-up. It’s worth doing whenever a site’s history, former industrial or commercial use, a service station, demolition, or imported fill, suggests contamination could be sitting in the ground. Common triggers we see include site acquisitions, subdivisions, redevelopments and former service station sites.
The right expertise, and the independent check
Not all site assessments need the same expertise. Environmental consultants typically cover a wide range of contamination issues, while occupational hygienists tend to specialise in asbestos. Airsafe brings both: site-specific risk assessment for organic and inorganic contaminants across industries from petrochemical and industrial to commercial, government and manufacturing, and decades of asbestos and hazardous material specialism, with asbestos identified in our own NATA-accredited laboratory and the wider soil and water chemistry analysed by an external NATA-accredited laboratory. Our consultants hold the certifications the work requires, including those the EPA requires for specific types of report.
Airsafe’s contaminated land reports are signed off by Michael Edwards, our Certified Environmental Practitioner (Site Contamination Specialist), CEnvP-SC No. 40039. That certification is recognised by the NSW EPA and gives a development application the best chance of progressing through council. A statutory Site Audit Statement is a separate, higher tier: it is issued by a separate EPA-accredited site auditor and is required only where works are regulated under the Contaminated Land Management Act or the Environmental Planning and Assessment Act, or where an authority requires one. Airsafe is not the statutory auditor; where one is needed, a separate accredited auditor is engaged.
We assess. A licensed contractor remediates.
If an assessment finds contamination that needs cleaning up, Airsafe writes the remediation or management approach and validates the work once it’s done, but we don’t carry out the remediation ourselves. A separate licensed contractor does that, and we can put the work out to tender and oversee it on your behalf. Because we don’t sell the remediation, our reports have no stake in the outcome.
A site assessment can also trigger legal obligations, for example, a duty to notify the EPA under the Contaminated Land Management Act where contamination is found above certain levels. We’ll tell you plainly where you stand and what you’re required to do.
From our case files
Assessments like these sit behind development applications and property decisions across NSW. Two recent examples:
- Arden Anglican School Junior Campus, Beecroft. A major campus redevelopment with Hornsby Shire Council: Airsafe carried out four preliminary site investigations and three detailed site investigations, approved by council as part of a large development application.
- 39 Carnation Avenue, Bankstown. A two-level childcare facility development application with Canterbury-Bankstown Council, taken through a detailed site investigation and a remedial action plan – the level of scrutiny that comes with a sensitive land use.
Both were signed off by Michael Edwards, our Certified Environmental Practitioner (Site Contamination Specialist).
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Frequently asked questions
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It’s the process of checking a property, asset or business for environmental risk before a transaction, so the buyer understands and can manage the liabilities that come with it. In practice, for land, that means an environmental site assessment: a study of the site’s history and condition, and where needed, sampling and testing, to work out whether it’s contaminated and what that would cost to deal with. It’s about going into a deal with your eyes open rather than inheriting someone else’s problem.
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Before you commit to a purchase, sale, lease or finance arrangement on a site that could be contaminated, and especially where the site has been used for industry, commercial activity, a service station, or has been demolished or filled. A council or the EPA may also require one as part of a rezoning or redevelopment. The earlier in a transaction you do it, the more room you have to negotiate or walk away. Call us on 1300 888 338 if you’re not sure.
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Phase 1 is a preliminary assessment, a desktop review of the site’s history and a site inspection, to judge whether contamination is likely and where. Many sites need nothing more than this. Phase 2 follows up with sampling and laboratory testing of soil, and groundwater where relevant, to confirm what’s actually there and how much. The work culminates in a report you can act on and put in front of a council, regulator or the other party.
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Sometimes, but it is a separate, higher tier from the assessment itself. Our contaminated land reports are signed off by Michael Edwards, our Certified Environmental Practitioner (Site Contamination Specialist), CEnvP-SC No. 40039, which is recognised by the NSW EPA and gives a development application the best chance of progressing through council. A statutory Site Audit Statement is issued by a separate EPA-accredited site auditor and is required only where works are regulated under the Contaminated Land Management Act or the Environmental Planning and Assessment Act, or where an authority requires one. Airsafe is not the statutory auditor; where one is needed, a separate accredited auditor is engaged.
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No. Airsafe is an independent consultant. We assess the site, write the remediation or management approach if one is needed, and validate the work once it’s done. The clean-up itself is carried out by a separate licensed contractor, which we can tender and oversee for you. Because we don’t do the remediation, our reports have no stake in the outcome.
Contact us for an environmental due diligence assessment today
Whether you’re buying, selling, financing or redeveloping, Airsafe will tell you what environmental liability a site carries, clearly, and in time to do something about it.
To organise an environmental due diligence assessment, call us on 1300 888 338.
Last updated: June 2026
