Preliminary Site Investigation in Sydney: Council & EPA Requirements
When lodging a Development Application (DA) in Sydney, one of the most common council requirements is a Preliminary Site Investigation (PSI). For developers, town planners, and architects, a PSI is not just a formality — it’s a legal and regulatory necessity under NSW EPA guidelines to confirm whether land is suitable for its proposed use.
At Confluence Environmental, we prepare council-ready Stage 1 PSI reports across Sydney and NSW. Our reports are designed to satisfy council Development Control Plans (DCPs), align with EPA and NEPM standards, and help projects move through the planning system without delays.
What is a Preliminary Site Investigation (PSI)?
A Preliminary Site Investigation (Stage 1 PSI) is the first step in assessing whether a site may be contaminated due to past or present land uses. A PSI is required under the NSW Contaminated Land Management Act 1997 and is guided by the National Environment Protection (Assessment of Site Contamination) Measure (NEPM, 2013).
The purpose of a PSI is to:
Identify potentially contaminating activities (PCAs) such as fuel storage, industrial workshops, service stations, uncontrolled fill, or demolition debris.
Review the site’s environmental setting, including geology, hydrogeology, groundwater vulnerability, and flood risk.
Conduct a desktop study and site inspection to flag potential contamination issues.
Provide a council-compliant report that determines whether the land is suitable for the proposed development.
If contamination is suspected, the PSI will recommend a Stage 2 Detailed Site Investigation (DSI), which includes soil, groundwater, or vapour sampling.
Why Sydney Councils Require a PSI
Sydney councils are legally obliged to consider land contamination when assessing a DA, rezoning, or subdivision. Almost every Local Environmental Plan (LEP) and Development Control Plan (DCP) contains provisions that require a PSI where contamination may be present.
Examples include:
City of Sydney DCP 2012 – Section 3.13 Contaminated Land
Canterbury-Bankstown DCP – Clause 6.10 Land Contamination
Parramatta Development Control Plan – Part 5.4 Contamination
Blacktown City Council DCP 2020 – Section B5 Land Contamination
Northern Beaches Council DCP 2020 – Part E12 Contamination and Hazard
Liverpool City Council Contaminated Land Policy
Inner West Council – Contaminated Land Planning Guidelines
Penrith Development Control Plan 2014 – Chapter C2 Land Contamination
Without a PSI, councils will not approve a DA where there is any risk of contamination. This makes the PSI a gateway requirement for most Sydney projects involving rezoning, subdivision, or redevelopment.
Key Guidelines Referenced in a PSI
A compliant PSI in Sydney will reference:
NSW EPA – Guidelines for Consultants Reporting on Contaminated Land (2020)
Managing Land Contamination: Planning Guidelines (EPA & Department of Planning, 1998; updated 2021)
National Environment Protection Measure (NEPM, 2013)
State Environmental Planning Policy (Resilience and Hazards) 2021 – Part 4.11 Contaminated Land
Work Health and Safety Regulation 2017 (asbestos and hazardous materials management)
By embedding these standards, a PSI becomes a defensible, regulator-ready document that satisfies both councils and the EPA.
What a PSI Involves
Desktop Review
Historical aerial photos, land titles, and zoning maps.
EPA contaminated sites registers and council planning files.
SafeWork notifications and records of past uses.
Site Walkover Inspection
Identification of asbestos fragments, fill, soil staining, chemical drums, or underground tanks.
Environmental Setting Review
Soil type, hydrogeology, flooding risk, and surrounding sensitive receptors.
Conceptual Site Model (CSM)
Assessment of potential contaminant sources, migration pathways, and receptors.
Council-Ready Report
Prepared to EPA and NEPM guidelines, with a clear conclusion on suitability for the proposed use.
When a Detailed Site Investigation (DSI) is Required
If a PSI identifies potential contamination, the next step is a Stage 2 Detailed Site Investigation (DSI). A DSI involves:
Soil sampling (surface and subsurface).
Groundwater monitoring where aquifers are present.
Soil vapour testing for sensitive land uses like childcare centres.
Comparison to NEPM Health Investigation Levels (HILs) and Ecological Investigation Levels (EILs).
The results of a DSI may then inform a Remediation Action Plan (RAP), followed by validation reporting to demonstrate suitability.
Common Sydney Scenarios Where a PSI is Required
Rezoning land from industrial to residential.
Subdivisions of former agricultural land (pesticides, arsenic).
Redevelopment of service stations, workshops, or depots.
Construction on land with uncontrolled fill or demolition waste.
Childcare centres, schools, or health facilities on potentially contaminated land.
Benefits of Completing a PSI Early
Avoid DA delays – councils will not progress without a PSI.
Protect feasibility – early risk identification prevents cost blowouts.
Satisfy financiers – banks and investors often require contamination due diligence.
Preserve land value – addressing contamination early avoids disputes and project risk.
Why Choose Confluence Environmental
Choosing the right consultant for your Stage 1 PSI in Sydney can make the difference between a smooth approval and a stalled DA. Here’s why developers, planners, and architects trust Confluence Environmental:
Sydney Council Experience
We regularly prepare PSI reports for City of Sydney, Parramatta, Liverpool, Canterbury-Bankstown, Northern Beaches, Inner West, Blacktown, and Penrith Councils. We know how each council interprets contamination guidelines, so our reports are tailored for acceptance — no unnecessary delays or resubmissions.
EPA- and NEPM-Aligned Methodology
Every PSI we prepare references the NSW EPA consultant reporting guidelines (2020), the NEPM (2013), and the Planning Guidelines for Contaminated Land (2021). This ensures your report is compliant, defensible, and ready for council assessment.
End-to-End Expertise
We provide full contaminated land services:
Stage 1 Preliminary Site Investigations (PSI)
Stage 2 Detailed Site Investigations (DSI)
Remediation Action Plans (RAPs)
This continuity of service means you don’t have to change consultants halfway — we take projects from desktop study through to final sign-off.
Fast Turnaround for DA Deadlines
We know DA timelines are critical. Our team offers:
Rapid mobilisation for inspections.
Clear communication throughout the process.
Reports delivered on time, to standard, first time.
Why We’re Better Than Competitors
Local credibility – We’re Sydney-based, with established council relationships.
Multi-disciplinary expertise – Contaminated land, asbestos, hazardous materials, groundwater, and occupational hygiene.
Director-led projects – Every PSI is overseen by our Principal Consultant, a Licensed Asbestos Assessor and environmental scientist with 8+ years’ experience.
Actionable solutions – We don’t just flag risks; we provide clear, practical steps that help move your project forward.
Proven results – Trusted by architects, planners, and developers for council-ready contamination reports that withstand scrutiny.
Frequently Asked Questions
Do all Sydney councils require a PSI?
Yes. If a site has a history of industrial use, uncontrolled fill, or increasing land use sensitivity, a PSI is mandatory.
Can one PSI be used across multiple councils?
Yes. A PSI written to NSW EPA and NEPM standards is accepted across Sydney and NSW.
How long does a PSI take?
Typically 1–3 weeks depending on site complexity and council requirements.
What if contamination is found?
We will recommend a Stage 2 DSI, and if required, develop a Remediation Action Plan (RAP) and manage remediation to completion.
Get a Council-Ready PSI in Sydney
If you are preparing a Development Application, rezoning, or subdivision in Sydney, a Preliminary Site Investigation (PSI) is often mandatory. Confluence Environmental delivers EPA-aligned, council-ready PSI reports that ensure compliance, protect land value, and keep your project moving.
📞 Contact us today to request a competitive quote for your Stage 1 PSI report in Sydney.