Contaminated Land Assessment, Management & Remediation - Sydney

Confluence Environmental are trusted environmental consultants in Sydney, delivering Preliminary Site Investigations (PSI), Detailed Site Investigations (DSI), Remedial Action Plans (RAP), Construction Environmental Management Plans (CEMP), and validation reports. Our assessments are led by a Certified Environmental Practitioner (CEnvP) and aligned with the ASC NEPM (Assessment of Site Contamination), NSW EPA reporting guidelines, and SEPP (Resilience & Hazards) 2021 – Chapter 4.

If you need a contaminated land assessment, site contamination assessment, or soil contamination report for your Development Application (DA), rezoning, subdivision, or due diligence, we deliver DA-ready reports that councils and planning authorities recognise.

When a PSI is Required in Sydney

A Preliminary Site Investigation (PSI) is the first step in assessing potential land contamination. Councils across Sydney, consistent with NSW planning requirements, may require a PSI to demonstrate that land is suitable for its proposed use.

You’ll typically need a PSI when:

• Council requests a report as part of a Development Application (DA), Planning Proposal, or Request for Additional Information (RAFI).

• Sensitive uses (residential, childcare, schools, aged care, recreation) are proposed on land with a history of industrial, commercial, or agricultural activity.

• Imported fill or neighbouring land uses may have introduced contamination risks.

• Rezoning, subdivision, or change of use triggers a contaminated land assessment.

• Property purchase or sale requires due diligence to confirm land suitability.

Our PSI Methodology (ASC NEPM–Aligned)

Each environmental site assessment is risk-based and aligned with ASC NEPM. A CSydney PSI typically includes:

• Desktop study – planning overlays, historical aerials, directories, trade listings, previous reports.

• Site walkover – visual signs of fill, staining, asbestos, or infrastructure that may indicate contamination.

• Receptors & pathways – identification of human health and environmental receptors, groundwater/surface water, and vapour pathways.

• Conceptual Site Model (CSM) – source–pathway–receptor diagrams and narrative.

• Risk screening & recommendations – determination of whether no further action is justified or a Detailed Site Investigation (DSI) is required.

Detailed Site Investigation (DSI) Sydney

If a PSI identifies data gaps or contamination risks, we design and complete a Detailed Site Investigation. Our DSIs include:

• Soil, groundwater and vapour sampling.

• Data Quality Objectives and laboratory analysis via NATA-accredited labs.

• Quantification of contamination risks to human health and the environment.

• Recommendations for remediation or validation.

A DSI is commonly required by councils as part of a DA when a PSI alone cannot rule out contamination risks.

Remediation Action Plans (RAP) & CEMPs

Where contamination is confirmed, our contaminated land consultants prepare a Remediation Action Plan (RAP) to outline how contamination will be managed or removed. RAPs set remediation objectives, identify suitable methods, and align with council and EPA requirements.

We also prepare Construction Environmental Management Plans (CEMP) to manage contamination risks during redevelopment, ensuring compliance with planning conditions and workplace health and safety requirements.

Site Validation

After remediation, we provide site validation reports to demonstrate that the land is suitable for its intended use. Validation includes confirmatory sampling and documentation in line with EPA contaminated land guidelines.

Due Diligence & Land Contamination

Our soil contamination and land contamination assessments also support due diligence for buyers, developers and investors. This ensures you understand potential liabilities before purchasing, leasing, or redeveloping land in Sydney.

Local Experience – Sydney Case Study

We recently completed a Preliminary Site Investigation (PSI) and Detailed Site Investigation (DSI) for a light industrial property on the Sydney. Our assessment identified imported fill and the potential for hydrocarbon impacts. Targeted DSI sampling confirmed the presence of metals in the fill, all of which were below the applicable commercial land-use criteria. With clear reporting and risk-based assessment, Council approved the Development Application without requiring additional remediation conditions.