Preliminary Site Investigations on the Central Coast

Confluence Environmental provides Preliminary Site Investigations (PSI) and contaminated land assessments throughout the Central Coast for development applications, rezoning, subdivision, redevelopment and property due diligence.

The Central Coast contains a diverse mix of former agricultural land, industrial and commercial areas, historical filling, fuel infrastructure and older development. These land-use histories can become important when sites are rezoned, subdivided or converted to more sensitive uses.

Our role is to determine whether historical activities represent a credible contamination risk to your project, what Council is likely to require and whether further investigation is actually necessary.

If you have received a contamination-related request from Central Coast Council, are preparing a Development Application or are considering purchasing a site, send us the property address, proposed development and available planning information and we can advise on an appropriate scope.

Call 1300 855 447 or request a proposal from our contaminated land team.

For a detailed explanation of the investigation process, see our Preliminary Site Investigation services across NSW.

Contaminated Land and Development on the Central Coast

Development across most of the Central Coast is now governed by the Central Coast Local Environmental Plan 2022 (CCLEP 2022) and Central Coast Development Control Plan 2022 (CCDCP 2022).

The consolidated controls commenced on 1 August 2022 and replaced the former Gosford and Wyong planning controls for most of the LGA.

The Gosford City Centre is an exception and remains subject to the relevant provisions of the State Environmental Planning Policy (Precincts—Regional) 2021.

Contamination also needs to be considered within the broader NSW planning framework, including Chapter 4 of State Environmental Planning Policy (Resilience and Hazards) 2021.

In practice, the amount of contaminated land assessment required depends on:

• the historical use of the property;

• what Council already knows about the site;

• the proposed development;

• whether the land use is becoming more sensitive;

• the presence of fill or former infrastructure;

• surrounding potentially contaminating activities; and

• previous environmental investigations.

This is why two development sites of a similar size can require very different contamination assessments.

Planning Proposals and Rezoning

Contaminated land assessment is particularly important where land is being rezoned.

Central Coast Council's current documentation requirements for requests to amend CCLEP 2022 identify a Phase 1 Contaminated Land Assessment as mandatory for all planning proposals.

In NSW terminology, this is generally undertaken as a Preliminary Site Investigation.

For developers and landowners considering rezoning, completing the PSI early can help establish whether contamination is likely to represent a constraint before the planning proposal progresses further.

It can also identify whether more detailed investigation should be incorporated into later stages of the project rather than becoming an unexpected issue during the Development Application.

Common Contamination Issues on the Central Coast

The appropriate investigation depends on the individual property, but several issues regularly arise across the region.

Former Agricultural and Horticultural Land

Large parts of the Central Coast have historically been used for orchards, market gardens, nurseries, poultry farming and other agricultural activities.

Depending on the history of the property, a PSI may need to consider:

• historical pesticide and herbicide use;

• chemical storage and mixing areas;

• former sheds and workshops;

• fuel storage;

• waste disposal;

• poultry or agricultural infrastructure; and

• historical filling.

The presence of a former orchard or nursery does not automatically mean the land is contaminated.

The purpose of the PSI is to determine what activities actually occurred and whether they create a credible contamination risk for the proposed use.

Imported and Uncontrolled Fill

Fill is another common issue across development sites.

Older properties may have been levelled, raised or modified without reliable records showing where the fill originated.

Fill can potentially contain:

• demolition debris;

• asbestos-containing materials;

• metals;

• hydrocarbons;

• ash or industrial material; or

• otherwise unsuitable material.

A PSI considers historical earthworks, aerial photographs, site levels and current site conditions to determine whether fill represents an issue requiring further assessment.

Workshops, Fuel and Commercial Land Uses

Former workshops, service stations, depots and commercial properties may also require consideration of:

• petroleum hydrocarbons;

• underground or above-ground fuel storage;

• oils and solvents;

• metals;

• waste storage; and

• historical spills or maintenance activities.

For redevelopment projects, identifying former infrastructure before design or excavation begins can substantially reduce uncertainty later.

Former Landfills and Historical Waste Disposal

The Central Coast also has a legacy of historical landfill sites.

Central Coast Council identifies a number of open-space and sporting facilities that occupy former landfill sites dating from the 1960s and 1970s. Council continues to monitor several of these sites for groundwater, surface-water and landfill-gas issues.

This does not mean land surrounding former landfill sites is necessarily contaminated.

However, where a property is located on, adjoining or close to historical filling or waste-disposal areas, the potential for migration through groundwater, surface water or landfill gas may need to be considered.

This is another reason why a PSI should consider surrounding land uses as well as the history of the subject property itself.

Why Local Knowledge Matters

A database search alone does not tell you the full history of a Central Coast property.

A site may currently contain a dwelling, warehouse or vacant paddock while having a historical use involving:

• horticulture;

• industrial activities;

• uncontrolled filling;

• workshops;

• fuel storage;

• waste disposal; or

• demolition.

A good PSI brings the available information together and asks whether those historical activities actually matter to the proposed development.

At Confluence Environmental, we focus on identifying credible Areas of Environmental Concern rather than automatically treating every historical activity as a reason for further investigation.

This helps ensure that any subsequent investigation is proportionate and directed toward the issues that genuinely require resolution.

Our Central Coast Experience

Confluence Environmental is based on the Central Coast and regularly undertakes contaminated land investigations throughout the region.

Our local experience includes:

• residential and subdivision projects;

• commercial and industrial redevelopment;

• former agricultural and horticultural land;

• childcare and other sensitive-use developments;

• sites containing imported fill;

• former workshops and fuel infrastructure;

• property acquisition due diligence; and

• contaminated land assessments prepared in response to Council and planning requirements.

Our contaminated land reports undergo technical quality assurance appropriate to the complexity of the project, and we regularly involve CEnvP Site Contamination (CEnvP-SC) and CPSS CSAM practitioners in the review of our work, including where formal certified endorsement is not specifically required.

Why Engage Confluence Environmental?

Local experience
We work across the Central Coast and understand the land-use histories and development issues that regularly arise in the region.

Proportionate investigation
Our aim is not to automatically recommend further investigation. We identify genuine data gaps and explain why additional work is or is not required.

Planning-focused advice
We understand that developers and planners need a clear answer about how contamination affects the proposed development—not simply a technical report.

Clear next steps
Our reports are designed to explain what has been identified, why it matters and what needs to happen next.

Preliminary Site Investigations Across the Central Coast

Confluence Environmental provides PSI and contaminated land services throughout the Central Coast, including:

Gosford and surrounds – West Gosford, East Gosford, North Gosford, Erina, Somersby and surrounding areas.

Southern Central Coast – Woy Woy, Umina Beach, Ettalong Beach, Kincumber and surrounding areas.

Northern Central Coast – Wyong, Tuggerah, Warnervale, Lake Munmorah, Toukley and surrounding areas.

Coastal areas – Terrigal, Avoca Beach, The Entrance and surrounding suburbs.

Need a PSI on the Central Coast?

If you are preparing a Development Application, planning proposal, subdivision or property transaction, send us:

• the site address;

• proposed development;

• Council correspondence;

• planning or concept drawings; and

• any previous environmental reports.

We can review the available information and develop a project-specific Preliminary Site Investigation scope.

Call Confluence Environmental on 1300 855 447 or request a proposal from our contaminated land team.

For more information about the investigation process, see our Preliminary Site Investigation services across NSW.