Contaminated land: assessment, disclosure and remediation for AU residential

TL;DR

A clean-looking site is not necessarily a clean site. If the land had a former use that involved chemicals, fuel, heavy metals, or waste, every Australian planning regime will require a contaminated land assessment before you can build residential. The first hit is a Stage 1 preliminary assessment (desktop and walkover, no sampling), typically $2,000-$5,000. If that raises a flag, you’re up for a Stage 2 detailed investigation (soil and water sampling), which runs $10,000-$50,000 or more depending on the size and complexity of the site. Remediation can cost anywhere from tens of thousands to millions. The cost surprise that breaks feasibilities is almost always a Stage 2 or remediation bill that wasn’t factored into the land price or the build programme. Check the history of the site before you put in an offer, not after development consent.

What this article is for

Contaminated land surfaces at the DA stage, in conveyancing due diligence, or mid-build when unexpected material is uncovered. This article maps the regulatory framework, explains Stage 1 vs Stage 2 assessments, covers the former uses that most commonly trigger investigation, and flags the gotchas that derail budgets and programmes across every state.

The regulatory framework

All Australian jurisdictions reference the same national assessment standard: the National Environment Protection (Assessment of Site Contamination) Measure 2013 (ASC NEPM), which sets health investigation levels (HILs), ecological investigation levels (EILs), and groundwater investigation levels (GILs) used as screening benchmarks nationally. On top of the NEPM, each state has its own legislation that determines when an assessment is required and who decides whether land is fit for residential use.

Jurisdiction	Primary instrument	Regulator	Key mechanism
NSW	SEPP (Resilience and Hazards) 2021 Chapter 4 (replaced SEPP 55 in 2022) + Contaminated Land Management Act 1997	EPA NSW	Consent authority must consider contamination before granting DA consent; mandatory remediation work categories; S10.7 certificate notation
VIC	Environment Protection Act 2017, s.39 general environmental duty	EPA Victoria	Environmental Audit Overlay (EAO) in planning schemes triggers pre-permit audit; s.208 audit certificate required for sensitive use on EAO land
QLD	Environmental Protection Act 1994	DESI (Dept. of Environment, Science and Innovation)	Environmental Management Register (EMR) + Contaminated Land Register (CLR); land on CLR cannot be used for sensitive use without remediation
WA	Contaminated Sites Act 2003	DWER (Dept. of Water and Environmental Regulation)	Contaminated Sites Register; mandatory written disclosure on any property transaction involving a listed site
SA	Environment Protection Act 1993 + Planning and Design Code overlays	EPA SA	Site contamination provisions embedded in planning scheme; mandatory assessment before sensitive use change
TAS	Environmental Management and Pollution Control Act 1994	EPA Tasmania	No mandatory pre-DA assessment but contamination is a material planning consideration; assessment required where use change involves sensitive use
ACT	Environment Protection Act 1997	Access Canberra	Site history review required for DA on potentially contaminated sites; ACT Planning escalates to EPA where contamination suspected
NT	Waste Management and Pollution Control Act 1998	NT EPA	Assessment required before subdivision or sensitive use change

Disclosure at title

State	Where contamination shows up
NSW	Section 10.7(2) planning certificate: must note any EPA NSW significantly contaminated land declaration, management order, voluntary management proposal, or remediation order. See Section 10.7 certificates NSW.
VIC	Section 32 vendor’s statement: vendor must disclose known contamination and EPA notices. Planning scheme overlay search reveals any Environmental Audit Overlay (EAO).
QLD	Title search: EMR and CLR listings attach to title and are searchable via CITEC Confirm or the DESI register.
WA	Prescribed Form 6 written disclosure: owner of listed land must give written notice to buyer, mortgagee, or lessee at least 14 days before transaction completion. Failure to disclose is a criminal offence.
SA	Planning and Design Code site contamination overlay search; EPA SA also maintains a public site contamination register.

Absence from a state register is not a clean bill of health. Registers only list sites that have been assessed, notified, and declared. An unassessed contaminated site will not appear.

Stage 1 vs Stage 2 site assessment

Assessment	What it involves	Typical cost	Output
Stage 1 Preliminary Site Investigation (PSI)	Desktop review: historical maps, title records, aerial photos, council records, EPA registers, Dial Before You Dig. Physical walkover. No soil or water sampling.	$2,000-$6,000	”No RECs identified” (no further action) or “RECs identified” (Stage 2 recommended)
Stage 2 Detailed Site Investigation (DSI)	Intrusive: soil borings, groundwater monitoring wells, sampling and lab analysis. Comparison against NEPM health investigation levels. Site-specific risk assessment if HILs exceeded.	$10,000-$80,000+	Site suitable as-is, suitable with risk management, or requires remediation before use

A Stage 1 clearance is not a clean bill of health. “No RECs identified” means no desktop evidence of a contaminating use was found, not that the land has been tested. If a Stage 2 finds exceedances, a remediation action plan (RAP) and a validation report confirming remediation are typically required before a construction certificate or building permit can issue.

Common contamination triggers

These former site uses are the ones that most commonly produce a contamination finding and trigger investigation requirements.

Former use	Typical contaminants	Notes
Service station or fuel depot	Petroleum hydrocarbons (BTEX), PFAS in fire-fighting foam	Often plumes in groundwater; remediation costs frequently exceed $500,000 on larger sites
Dry cleaner or laundry	Chlorinated solvents (PERC/PCE, TCE)	Pre-1991 sites are highest risk; dense non-aqueous phase liquids (DNAPL) can sit deep in the profile
Former orchard or market garden	Organochlorine pesticides (DDT, dieldrin), lead arsenate, copper	NSW EPA has specific guidance for orchards; lead arsenate from apple sprays common in older growing regions
Former industrial site	Variable: heavy metals, asbestos, hydrocarbons, solvents, cyanide	Broad category; stage 1 historical research is critical
Filled site (unknown fill origin)	Asbestos, hydrocarbons, construction waste, putrescible material	Very common in older suburban infill lots that were topographically altered
Former landfill or tipping site	Landfill gas, leachate, asbestos, heavy metals, putrescible waste	Buffer zones and gas investigation usually required even after formal closure
Former sheep dip or veterinary site	Organochlorine pesticides, arsenic	Common in rural residential and peri-urban rezoning land

DA implications

In NSW, Chapter 4 of the SEPP (Resilience and Hazards) 2021 is the direct planning mechanism. The key operative clause (clause 4.6) requires that a consent authority must not grant development consent unless it has:

Considered whether the land is contaminated.
If contaminated, satisfied itself that the land is suitable in its contaminated state for the proposed use, or that it will be suitable after remediation.
If remediation is required, satisfied itself that the remediation will be carried out.

Before determining a DA that involves a change of use on land with a potentially contaminating history, the consent authority must consider a preliminary investigation report (Stage 1). If the Stage 1 raises issues, a Stage 2 (and possibly a remediation action plan) becomes a condition of consent or a pre-determination requirement.

Remediation under Chapter 4 splits into two categories:

Category 1 remediation work: requires development consent before it starts. This applies to high-risk work such as excavation and removal of contaminated soil from a sensitive land use site.
Category 2 remediation work: does not require consent but the council must be notified before work starts and again when it is complete. Lower-risk work such as in-situ treatment and capping typically falls here.

A council may impose conditions requiring the submission of a Stage 2 report, a remediation action plan, and a validation report (confirming remediation outcomes) as conditions of consent on any DA where contamination is a concern.

State variance

State	Key variance
NSW	SEPP (Resilience and Hazards) 2021 Chapter 4 is the direct planning obligation. DA applicant must provide a Stage 1 PSI for any potentially contaminated land. Consent authority cannot approve without considering it. S10.7 certificate discloses EPA register entries.
VIC	Planning scheme Environmental Audit Overlay (EAO) is the trigger. Land with an EAO cannot be used for sensitive residential use until a s.208 environmental audit statement or certificate of environmental audit is issued under the EP Act 2017. No EAO on title does not mean the land is clean, just that the overlay has not been applied.
QLD	Two registers: EMR (land with notifiable activity history) and CLR (land requiring remediation). CLR land cannot proceed to residential use without remediation to a standard set by DESI. EMR land requires a site suitability statement from a site suitability evaluator before residential development is approved.
WA	Contaminated Sites Register (DWER). Mandatory written disclosure on any transaction involving listed land. Classification system: contaminated, remediated for restricted use, possibly contaminated, decontaminated. Residential development on “contaminated” classified land requires a site remediation plan and DWER sign-off.
SA	Contamination provisions operate through the Planning and Design Code. A site contamination report from an accredited site contamination assessor is required for change of use to sensitive use. The EPA SA may become the relevant authority if remediation is needed.
TAS/ACT/NT	No equivalent mandatory register trigger, but contamination is a material planning consideration. In practice, councils routinely request a Stage 1 PSI as part of any DA on land with a contaminating land-use history.

What can go wrong

Assuming a Stage 1 clearance means no problem. “No RECs identified” in a Stage 1 means there is no desktop evidence of a contaminating use, not that the soil has been tested. Unexpected finds during earthworks still happen. Build a contingency in every programme on a site with urban or peri-urban history.

Skipping pre-purchase due diligence. Former orchards, service stations, and filled sites often sell as clean vacant land. A Stage 1 PSI before offer, at under $5,000, can avoid a six-figure surprise after exchange.

Underestimating remediation timeframes. Petroleum hydrocarbon and chlorinated solvent plumes can take years to remediate. In-situ treatment requires monitoring periods. If a DA condition requires remediation before construction, it must be in the programme and the feasibility from day one.

Expecting title searches to catch everything. A site with a contaminating history that has never been assessed will not appear on any register.

Missing the sale price impact. A management order or CLR listing is public and stays on title until formal remediation and delisting. Land with a known listing priced at market rates without factoring in remediation cost is a common feasibility error.

SEPPs in NSW covers the broader structure of which SEPPs apply to which issues; contaminated land sits inside the Resilience and Hazards SEPP.
Section 10.7 certificates NSW explains the full list of what a planning certificate reveals and how to order one.
Planning instrument hierarchy AU puts the state-by-state planning framework in context.
Acid sulfate soils is a related ground-condition planning risk that can trigger its own assessment and DA condition obligations.

References

State Environmental Planning Policy (Resilience and Hazards) 2021 (NSW), Chapter 4, via legislation.nsw.gov.au (verified 2026-05-23).
NSW Planning Portal, contaminated lands guidance, via planning.nsw.gov.au (verified 2026-05-23).
National Environment Protection (Assessment of Site Contamination) Measure 2013, via nepc.gov.au (verified 2026-05-23).
EPA NSW role of planning authorities in contaminated land, via epa.nsw.gov.au (verified 2026-05-23).
EPA Victoria, duty to manage contaminated land (s.39 EP Act 2017), via epa.vic.gov.au (verified 2026-05-23).
Victorian Environmental Audit Overlay overview, via environment.vic.gov.au (verified 2026-05-23).
Queensland land registers (EMR and CLR), via qld.gov.au (verified 2026-05-23).
WA Contaminated Sites Act 2003, via legislation.wa.gov.au (verified 2026-05-23).
NSW EPA, assessing former orchards and market gardens, via epa.nsw.gov.au (verified 2026-05-23).