Somersby Preliminary Site Investigation – Proposed Function Centre Development

Confluence Environmental was engaged to undertake a Preliminary Site Investigation (PSI) for a property in Somersby, NSW, proposed for redevelopment as a function and events centre.

The investigation was undertaken in response to requirements arising through proceedings in the NSW Land and Environment Court, with the objective of independently assessing whether historical land uses had the potential to present contamination risks relevant to the proposed change in land use.

The site had historically operated as a commercial orchid and nursery operation, introducing specific considerations relating to legacy agricultural activities, imported fill and historical chemical use.

Description of Services

Confluence Environmental completed a comprehensive contaminated land assessment in general accordance with NSW EPA and planning guidance applicable to preliminary investigations.

The scope of work included a detailed desktop review of historical aerial imagery, planning records and land use information to establish a clear understanding of historical site activities and potential contaminant sources. This was supported by a systematic site inspection to assess current site conditions, surface materials and any visual indicators of contamination.

A key component of the investigation was the development and refinement of a conceptual site model (CSM), identifying potential sources, pathways and receptors relevant to the proposed function centre land use.

The PSI was prepared to directly address the matters raised through the court process and to provide a defensible, evidence-based foundation for planning and regulatory decision-making.

Site-Specific Considerations

While horticultural land uses are often perceived as low risk, the historical operation of an orchid and nursery facility introduced several potential contamination considerations, including:

• Historical use of pesticides, herbicides and fertilisers

• Potential importation of fill or growing media

• Storage and handling of chemicals associated with commercial horticulture

• Localised disturbance associated with past structures and infrastructure

These factors required careful assessment to distinguish theoretical risk from actual site conditions and to avoid unnecessary escalation of investigation scope.

Key Challenges

The primary challenge associated with the project was responding to the elevated level of scrutiny associated with a Land and Environment Court–driven assessment, while maintaining a proportionate investigation approach consistent with a preliminary level of assessment.

Clear articulation of assumptions, limitations and conclusions was essential, particularly where the absence of evidence for contamination needed to be justified in a regulatory and legal context.

The PSI was structured to transparently demonstrate how conclusions were reached, and to clearly identify whether any further investigation would be warranted prior to development.

Outcomes

The completed PSI provided a clear, independent assessment of contamination risk relevant to the proposed function centre development. The report established a defensible understanding of site history and environmental risk, supporting informed decision-making by planners, regulators and legal representatives.

By addressing the court-raised concerns directly and logically, the investigation enabled the project to progress without unnecessary escalation to intrusive assessment where it was not justified by site conditions.

Why This Project Matters

Court-triggered investigations require a higher standard of clarity, justification and documentation than routine planning assessments. This project demonstrates the importance of:

• Robust site history analysis

• Clear conceptual site modelling

• Proportionate investigation aligned with actual risk

• Reporting that withstands regulatory and legal scrutiny

Confluence Environmental’s approach ensured that contamination risk was assessed thoroughly, transparently and efficiently, providing confidence to all stakeholders involved.