Preliminary Site Investigations
Request a Preliminary Site Investigation Proposal
Confluence Environmental prepares Preliminary Site Investigations for development applications, planning proposals, subdivisions, property transactions and environmental due diligence across NSW.
Our assessments are scoped to the site history, proposed land use and available information, with a focus on identifying credible contamination risks and determining whether further investigation is warranted.
Reports are subject to technical quality assurance appropriate to the complexity of the project, with CEnvP Site Contamination (CEnvP-SC) and CPSS CSAM review or endorsement available where required.
To request a proposal, provide the site address, proposed development and any available Council correspondence, development plans or previous environmental reports.
We will review the available information and develop an appropriate scope for the Preliminary Site Investigation.
Preliminary Site Investigation and Contamination Assessment
Confluence Environmental undertakes Preliminary Site Investigations (PSIs) to identify actual or potential contamination risks and provide a clear technical basis for planning, development and property decisions.
A PSI is generally the first stage of contaminated land assessment and is used to establish the site history, identify potentially contaminating activities and determine whether further investigation or management is warranted.
The assessment considers the sources, pathways and receptors relevant to the site and proposed land use and develops a preliminary Conceptual Site Model to evaluate potential contamination risks.
Depending on the findings, the PSI may demonstrate that no further contaminated land assessment is required, identify specific data gaps requiring further investigation, or establish the basis for a Detailed Site Investigation.
Preliminary Assessment Scope
The assessment scope is developed from the site history, environmental setting, proposed development and available site information.
Depending on the project, a PSI can include consideration of:
historical land use and development, including former buildings and infrastructure;
imported fill and earthworks that may represent a potential contamination source;
industrial, commercial and agricultural activities associated with the property;
fuel, chemical and waste storage and other potentially contaminating infrastructure;
surrounding land uses that may influence the site;
geology, groundwater and surface water conditions; and
future land use and sensitive receptors relevant to the proposed development.
Potential contamination sources are documented as Areas of Environmental Concern and associated Contaminants of Potential Concern where appropriate.
Assessment Approach
Effective preliminary assessment begins with understanding how the site has been used and whether those activities could materially affect the proposed development.
We review available historical aerial imagery, planning information, regulatory records, previous environmental reports, geology, hydrogeology and other relevant information before undertaking a site inspection.
The available information is then integrated into the Conceptual Site Model to assess potential source–pathway–receptor relationships and identify material data gaps.
Where reliable previous investigation data are available, these are considered as part of the assessment rather than unnecessarily repeating existing work.
Clear, Defensible Outcomes
A Preliminary Site Investigation should provide more than a summary of historical land uses.
Our reports identify the contamination risks relevant to the site, assess the significance of the available evidence and provide a clear basis for determining whether further work is required.
Recommendations may include:
no further contaminated land assessment;
asbestos or hazardous materials assessment;
waste classification or soil reuse assessment; or
other contamination management measures relevant to the project.
The objective is to provide the information required to support a clear and defensible project decision.
Integrated with Planning and Development
Preliminary contamination assessment is undertaken with consideration of the broader project.
We consider matters such as proposed land use, development layout, excavation, existing buildings, sensitive receptors and future construction activities when assessing the significance of potential contamination risks.
This allows identified issues to be addressed at the appropriate project stage and provides a sound technical basis for Development Applications, planning proposals, property transactions and subsequent contaminated land assessment.
Experience Across Diverse Development Settings
Confluence Environmental has experience undertaking Preliminary Site Investigations across commercial, industrial, residential, agricultural, infrastructure and mixed-use development environments.
Our work includes assessments of former industrial properties, historical fuel infrastructure, agricultural land, imported fill, sensitive-use developments, large rural holdings and sites involving multiple Areas of Environmental Concern.
We also prepare PSIs for projects subject to independent technical review and where subsequent contaminated land investigations may be undertaken within Site Auditor frameworks.
Preliminary Site Investigations Across NSW
Confluence Environmental undertakes Preliminary Site Investigations across Newcastle and the Hunter, Lake Macquarie, Maitland, the Central Coast, Sydney and Greater Sydney, the Mid Coast, Mid North Coast and regional NSW.
Featured Projects
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![Confluence Environmental vehicle during a detailed site investigation at a rural property]()
North Richmond Preliminary Site Investigation
Redevelopment of historically used land can require early consideration of potential contamination to understand whether it may constrain the proposed land use. Confluence Environmental completed a Preliminary Site Investigation for a proposed mixed-use development in NSW, identifying key Areas of Environmental Concern and developing the Conceptual Site Model for the site. The assessment established the basis for targeted further investigation and provided a clear pathway for progressing the development through the contaminated land assessment process.
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![A commercial property during a PSI impacted by contaminated fill material]()
Bathurst Preliminary Site Investigation
Legacy industrial activities, historical filling and former fuel infrastructure can introduce uncertainty when land is proposed for redevelopment. Confluence Environmental completed a Preliminary Site Investigation for a proposed industrial development in regional NSW, identifying the key Areas of Environmental Concern and potential contamination risks relevant to the future land use. The assessment established the Conceptual Site Model and provided the technical basis for determining the scope of further investigation required to support the development.
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![Confluence car parked with a view of the central tablelands during a detailed site investigation of the Uungula Wind Farm Project]()
Uungula Wind Farm Project Preliminary Site Investigation
Large-scale renewable energy projects can extend across diverse geological settings and land-use histories, creating a range of potential environmental constraints. Confluence Environmental completed a Preliminary Site Investigation for a major wind farm development in regional NSW, identifying key Areas of Environmental Concern and potential contamination and naturally occurring mineral risks across the project area. The assessment established the Conceptual Site Model and provided the technical basis for targeted further investigation and environmental management as the project progressed.
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![A former factory at Woy Woy Storage Park subject to numerous potentially contaminating activities and subject to Confluence Environmental Preliminary Site Investigation]()
Woy Woy Preliminary Site investigation
Operational commercial sites can present contamination assessment challenges where buildings and infrastructure limit access to parts of the property. Confluence Environmental completed a Preliminary Site Investigation for a storage facility on the NSW Central Coast, identifying the key Areas of Environmental Concern, access limitations and potential contamination risks relevant to the proposed redevelopment. The assessment established the Conceptual Site Model and provided the basis for a staged investigation strategy as the site became progressively accessible.
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![A Confluence consultant conducts a Site walkover during a Preliminary Site Investigation of Lake Munmorah]()
Lake Munmorah Preliminary Site Investigation
Planning for future residential development requires early consideration of historical land use and potential contamination constraints. Confluence Environmental completed a Preliminary Site Investigation for a proposed residential rezoning project on the NSW Central Coast, assessing potential risks associated with historical site activities, imported fill and the broader environmental setting. The assessment established the Conceptual Site Model and provided the technical basis for progressing the planning proposal and identifying any further investigation required at subsequent development stages.
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![A former residential property subject to a Preliminary Site Investigation to determine future suitability]()
Muswellbrook Preliminary Site Investigation
Redevelopment of established public land can require consideration of historical fill, former structures and building-related contamination risks. Confluence Environmental completed a Preliminary Site Investigation for a Council-managed site in Muswellbrook, NSW, identifying the key Areas of Environmental Concern and developing the Conceptual Site Model for the proposed works. The assessment established a proportionate pathway for managing the identified risks and informed the environmental requirements for subsequent development activities.
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![A residential property requiring a Preliminary Site Investigation to determine suitability for a proposed subdivision]()
Goulburn Preliminary Site Investigation
Residential subdivision of previously disturbed land can require early assessment of historical filling and other potential contamination constraints. Confluence Environmental completed a Preliminary Site Investigation for a proposed residential subdivision in Goulburn, NSW, identifying uncontrolled fill as the principal Area of Environmental Concern and developing the Conceptual Site Model for the site. The assessment found no evidence of widespread contamination that would preclude the proposed development and established the basis for targeted further investigation to support the Development Application.
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![A commercial property nearby a copper smelter subject to a Preliminary Site Investigation]()
Port Kembla Preliminary Site Investigation
Industrial precincts can present contamination risks even where potentially contaminating activities have not occurred directly on the site. Confluence Environmental completed a Preliminary Site Investigation for a proposed commercial development in Port Kembla, NSW, identifying potential risks associated with historical industrial emissions, hazardous building materials and localised hydrocarbon impacts. The assessment established the Conceptual Site Model and provided the basis for targeted further investigation and management to support the proposed development.
Differentiators
Technical Leadership
DSI scopes, investigation strategies and reporting maintain direct senior technical involvement, with CEnvP-SC endorsed reporting available where required.
EPA Site Auditor Review Experience
Our team has extensive experience preparing investigations for independent review under the NSW EPA Site Auditor Scheme, including complex, multi-stage contaminated land projects.
Integrated Environmental Capability
Our contaminated land capability is supported by in-house expertise across asbestos and hazardous materials, occupational hygiene, waste classification and environmental monitoring, allowing related risks to be addressed within a coordinated project team.
Major Project Delivery
Confluence has delivered investigation and risk-management programs for complex infrastructure and development projects, including the Uungula Wind Farm and large former industrial sites involving soil, groundwater, surface water and soil vapour assessment.
In-House Field Capability
We maintain our own core investigation, monitoring and field equipment, reducing reliance on equipment hire and external mobilisation and providing greater control over project scheduling and field delivery.
Specialist Consultancy Model
Clients retain access to experienced technical practitioners throughout the project, combining the capability required for complex investigations with the responsiveness of a specialist consultancy.
Preliminary Site Investigation Resources
Learn more about Preliminary Site Investigations, contamination assessment and the NSW planning process in our technical guides.