Contamination Reports NSW DA 2026: When Councils Require a PSI, DSI, RAP or Site Audit

Answer first: Greater Sydney consent authorities must consider contamination under Chapter 4 of the State Environmental Planning Policy (Resilience and Hazards) 2021. Where a change of use hits the Planning Guidelines triggers — investigation area, Table 1 history, or incomplete knowledge for sensitive uses — lodge a Preliminary Site Investigation (PSI) with the DA. A Detailed Site Investigation (DSI), Remedial Action Plan (RAP) or EPA-accredited Site Audit Statement follows only when the PSI findings warrant it.

Author: Franz Phan, Senior Planning Consultant, giantA Pty Ltd · Updated 29 September 2026

When must a NSW consent authority consider contamination on a DA?

Under section 4.6 of the State Environmental Planning Policy (Resilience and Hazards) 2021 (Resilience and Hazards SEPP), a consent authority must not consent to development unless it has considered whether the land is contaminated; is satisfied the land is suitable in its contaminated state (or will be after remediation) for the proposed purpose; and, if remediation is required, is satisfied the land will be remediated before that use begins.

Before determining a change-of-use application on land specified in section 4.6(4), the consent authority must consider a report on a preliminary investigation carried out in accordance with the contaminated land planning guidelines. The applicant must provide that report. The consent authority may then require a detailed investigation if the preliminary findings warrant it.

Section 4.6(4) captures:

• land within an investigation area
• land on which a purpose referred to in Table 1 to the contaminated land planning guidelines is being, or is known to have been, carried out
• land proposed for residential, educational, recreational, child care or hospital use where knowledge of Table 1 history is absent or incomplete, and such development would have been lawful during the period of incomplete knowledge

Chapter 4 of the Resilience and Hazards SEPP now houses the former SEPP 55 remediation framework. NSW Planning’s contaminated lands overview confirms that planning decisions still turn on the Managing Land Contamination Planning Guidelines alongside EPA regulation under the Contaminated Land Management Act 1997 for sites serious enough to justify EPA intervention.

Sources: Resilience and Hazards SEPP — section 4.6 · NSW Planning — Contaminated lands · NSW EPA — Role of planning authorities.

Related giantA pathway reading: DA & CDC Checklist NSW 2026 · CDC vs DA Approval NSW · Specifications required for DA lodgement · Statement of Environmental Effects NSW DA 2026.

What is the difference between a PSI, DSI, RAP and Site Audit Statement?

Councils and the NSW EPA use staged investigation language. City of Sydney’s Contaminated Land Policy (approved November 2022) and Canada Bay’s Contaminated Land Policy both map the same broad sequence used in the EPA’s Consultants reporting on contaminated land guidelines (2020).

Sources: NSW EPA — Consultants reporting on contaminated land (PDF) · City of Sydney Contaminated Land Policy (PDF) · Canada Bay Contaminated Land Policy (PDF).

When do Greater Sydney councils typically require a PSI with the DA?

Assessing officers ask for a PSI when history, zoning or the proposed use raises a reasonable contamination question — not only on obvious former industrial yards.

Canada Bay restates the section 4.6 triggers and adds practical “reasonable grounds” cases: incomplete prior investigation or remediation information; regulatory restrictions that may relate to contamination; pollution incidents or illegal dumping on council records; and adjoining land with potentially contaminating activities where migration is likely. If the PSI justifiably concludes the site is suitable, further investigation is not required.

Inner West DCP Part 2.11 Contaminated Land requires that for known or suspected contaminated sites, a Phase 1 PSI or Phase 2 DSI be submitted by a certified consultant in accordance with the NSW EPA consultant reporting guidelines — covering nature and extent of contamination, fitness for the proposed use, and remediation actions where needed. Where remediation is required, works follow a RAP; development may only proceed once council has a Validation Report and, where necessary, a Section A Site Audit Statement from an EPA-accredited Site Auditor.

City of Sydney Contaminated Land Policy aligns DA assessment with Resilience and Hazards SEPP Chapter 4 and the Planning Guidelines, and defines PSI as the normally desktop (sometimes limited-field) investigation that identifies past or present potentially contaminating activities and decides whether a DSI is needed.

Do not invent a universal fee or dollar threshold for when a PSI is required. Triggers are planning and risk-based. Check the local contaminated-land policy or DA lodgement guide, and read the Section 10.7 planning certificate carefully.

Sources: Canada Bay Contaminated Land Policy · Inner West DCP — 2.11 Contaminated Land · City of Sydney Contaminated Land Policy.

What must a council-ready PSI include?

Generic “no contamination” letters are rejected. The NSW EPA’s 2020 Consultants reporting on contaminated land guidelines (made under section 105 of the Contaminated Land Management Act 1997) set the PSI objective: assess whether contamination has the potential to exist and whether further investigation is needed. Key factors include:

1. Purpose of the investigation — proposed use and planning pathway stated clearly.
2. Site history — past and present potentially contaminating activities (on- and off-site), using planning authority and EPA information plus site inspection.
3. Potentially contaminated media — soil, sediment, groundwater, surface water, soil vapour, indoor/outdoor air as relevant.
4. Site condition and setting — surrounding environment, geological and hydrogeological context.
5. Preliminary assessment — contaminants of potential concern, including emerging contaminants identified during the PSI.
6. Conceptual site model (CSM) — sources, pathways, receptors and exposure mechanisms; assumptions, uncertainty and data gaps.
7. Recommendations — no further work, limited preliminary sampling, or progression to DSI / RAP.

The EPA guidelines treat a CSM as essential at PSI stage. Where a complete site history clearly shows non-contaminating activities, no off-site impacts and no contamination indicators on inspection, further sampling may not be needed. Where history is incomplete or contaminating activities are suspected, preliminary sampling may be required to decide on a DSI.

For reports going to the EPA, the Contaminated Land Consultant Certification Policy requires preparation or review/approval by a certified contaminated land consultant (CEnvP Site Contamination or equivalent CPSS CSAM). Many Greater Sydney councils expect the same standard for DA-grade reports — confirm your council’s wording.

Sources: EPA Consultants reporting guidelines (PDF) · EPA statutory guidelines index · EPA — Engaging a consultant.

How do ASC NEPM and the Planning Guidelines sit behind the PSI?

Two references sit behind almost every council-ready contamination package:

• National Environment Protection (Assessment of Site Contamination) Measure 1999 (ASC NEPM, as amended) — the key EPA-approved national guidance for assessment process, site characterisation and investigation levels. The EPA consultant reporting guidelines require consultants to work to ASC NEPM Schedules A and B with other statutory guidelines.
• Managing Land Contamination: Planning Guidelines (the SEPP 55–Remediation of Land guidelines still named in section 4.6) — the framework planning authorities use for early identification, rezoning and DA decision-making, planning certificates, and remediation process design.

Practically: the Planning Guidelines tell the consent authority when a preliminary or detailed investigation is required; ASC NEPM and the EPA reporting guidelines tell the consultant how to investigate and report so those conclusions can be relied on.

Sources: Managing Land Contamination Planning Guidelines (PDF) · NSW Planning — Contaminated lands.

How should contamination sit in the SEE and Planning Portal package?

The Statement of Environmental Effects remains the integrating planning narrative. The PSI / DSI / RAP prove the technical conclusions. A common RFI pattern is a thin SEE that says “see contamination report” with no synthesis — or a PSI that assesses an outdated architectural or use description.

• Keep in the SEE: why contamination is relevant under Resilience and Hazards SEPP section 4.6; a short summary of history and PSI conclusions; whether remediation is proposed and how suitability will be achieved before the use begins; cross-reference to the PSI/DSI/RAP PDFs on the NSW Planning Portal.
• Keep in the consultant reports: CSM, sampling rationale, laboratory data, risk discussion, RAP staging and validation criteria.
• Match the drawings: proposed use, excavation depth, basement/OSD tanks, fill import/export and landscaping must match what the consultant assessed.

Contamination packages often coordinate with sister lodgement reports — Construction Management Plans, Waste Management Plans (especially soil disposal classification), and Landscape Plans where capping, deep soil or imported fill interfaces with remediation. Keep one coordinator so versions do not drift.

Brief the consultant early with survey, DA drawings, Section 10.7 certificates, known prior uses/tanks/fill/asbestos history, and any previous PSI/DSI/RAP/SAS. Freeze a “contamination revision base” if the architecture is still moving. Related: SEE NSW DA 2026 · Architectural services.

What are the common RFI traps on contamination reports?

• Generic “no contamination” letters with no site history, no CSM and no data-gap discussion.
• Outdated reports that pre-date a change of use, a new basement depth, or a different sensitive use.
• Missing CSM — the EPA guidelines treat the conceptual site model as essential at PSI stage.
• PSI that should have been a DSI — where Table 1 history is clear or sampling already shows impacts, some councils expect the deeper package (sometimes including a RAP) at lodgement.
• Ignoring Section 10.7 notations — EPA declarations, management orders, voluntary management proposals, ongoing maintenance orders and site audit statements must appear on section 10.7(2) certificates; councils may also record other information under section 10.7(5).
• Uncertified consultants where the council or EPA pathway expects CEnvP(SC) / CPSS CSAM (or equivalent) sign-off.

CDC versus DA — a soft note on contaminated sites

Complying Development under the Codes SEPP is a separate, highly constrained pathway. Contaminated or formerly contaminating sites frequently need a Development Application so the consent authority can apply Resilience and Hazards SEPP section 4.6 properly. If contamination history is live, verify CDC exclusions and council advice before locking a CDC programme — treat DA + SEE + PSI as the safer default until those checks are clear. Confirm the current Codes SEPP and your certifier’s scope; this article does not invent CDC clause numbers.

Pathway reading: CDC vs DA Approval NSW · DA & CDC Checklist.

Frequently asked questions

Do all NSW residential DAs need a Preliminary Site Investigation?

No. Section 4.6 always requires the consent authority to consider contamination, but a formal PSI report is required for the change-of-use situations in section 4.6(4) — and councils may also require one on reasonable grounds under their contaminated land policies. Check your LGA lodgement guide and Section 10.7 certificate before assuming exemption.

Who should prepare the PSI or DSI for Greater Sydney councils?

A suitably qualified contaminated land consultant. Reports submitted to the EPA must be prepared or reviewed/approved by a certified consultant under the EPA Contaminated Land Consultant Certification Policy. Inner West expressly requires certified consultants reporting to the NSW EPA guidelines for known or suspected contaminated sites.

When does a PSI become a DSI?

When the preliminary investigation shows potential or actual contamination that may make the land unsuitable for the proposed use. Resilience and Hazards SEPP section 4.6(3) lets the consent authority require a detailed investigation if the preliminary findings warrant it.

What is a Site Audit Statement, and is the site then “clean”?

A Site Audit Statement is issued by a NSW EPA-accredited Site Auditor after an independent site audit. Canada Bay’s policy notes that a SAS does not mean the site is clean — it confirms suitability for a particular use. Inner West may require a Section A SAS with validation where remediation was needed.

Can remediation be left as a condition after DA consent?

Consent authorities still need to be satisfied under section 4.6 that the land will be suitable after remediation and that remediation will occur before the use begins. Some councils expect a RAP at lodgement where remediation is already indicated, rather than deferring the entire contamination package.

How do Section 10.7 certificates relate to contamination?

Section 10.7(2) certificates must record prescribed Contaminated Land Management Act matters (significantly contaminated land, management orders, approved voluntary management proposals, ongoing maintenance orders, and site audit statements). Councils may also include other contamination information under section 10.7(5).

If you are preparing a Greater Sydney DA and need the contamination story coordinated with architecture, SEE and Portal lodgement, ask giantA via Help — we can review whether a PSI is likely and how it should match your drawings and sister reports. Soft next step only — no invented fees or turnaround promises. Also see architectural services, DA & CDC checklist and specifications required.