The problem
An established industrial property in South Australia is under contract for acquisition and staged redevelopment into multi‑unit warehouses. A 2008 site assessment recorded shallow fill (rubble and gravel) with no visual contamination indicators but no laboratory testing. Future multi‑tenancy raises practical risks from fuels, oils, solvents, concrete additives and everyday trade waste.
What iEnvi reviewed
iEnvi reviewed the historic assessment and public records through 2025 and found the site has remained in industrial use. Stakeholders want a proportionate strategy that gives certainty on contamination risks, regulatory standing and spoil disposal pathways without committing unnecessarily to intrusive investigation.
Recommended scope — a proportionate PSI first
Recommended first step: an updated Preliminary Site Investigation (PSI) prepared in accordance with the national site contamination framework (ASC NEPM). The PSI should include:
- desktop historical review and development of a Conceptual Site Model (CSM);
- full site inspection (visually examine surfaces, floor slabs, drainage, staining, dumped materials and standing structures);
- an SA EPA Section 7 search and review of council planning and building files for historic uses, notices or previous remediation work; and
- simple, documented lines of enquiry with current tenants/operators about on‑site chemicals, fuel storage, bunding and spill history.
Why a PSI first?
A properly scoped PSI follows the ASC NEPM staged approach (PSI → DSI only if triggered). This gives a defensible, efficient decision path: avoid routine drilling where no indicators exist, but enable rapid escalation to a targeted Detailed Site Investigation (DSI) if the PSI identifies triggers.
Triggers that justify a targeted DSI or intrusive testing
- evidence of bulk fuel, chemical or solvent storage, or historic service stations on or adjacent to the title;
- visible or odorous hydrocarbon staining, unsealed high‑use work areas, on‑site maintenance pits or trade‑waste drains;
- large volumes of dumped or unknown fill (including recycled fill), or obvious demolition rubble that could contain asbestos; and
- a material change in planned land use or a requirement by a regulator or financier for quantitative data.
Excavation, spoil and waste classification
Before any excavation, undertake waste classification testing so spoil can be lawfully managed and costed. Follow a recognised waste classification procedure (stepwise chemical assessment and leachability tests where relevant) rather than assuming clean‑fill status — this materially reduces disposal risk and cost surprises at construction stage.
Groundwater and bore use
Maintain a prohibition on using groundwater unless and until site‑specific testing and hydrogeological assessment confirm it is suitable. In South Australia the EPA has used formal Groundwater Prohibition Areas (GPAs) where local groundwater is known to be contaminated; check whether the property sits within any GPA as part of the PSI.
Unexpected finds protocol
Adopt and document an unexpected‑finds protocol to be used by discovery during construction. Minimum elements:
- stop‑work and cordon procedures;
- initial visual assessment and photograph record;
- rapid sample collection and analysis by a NATA‑accredited laboratory for asbestos, petroleum hydrocarbons and metals (or other suspected contaminants);
- notification pathways to client, principal contractor and regulator as required; and
- emergency handling and temporary segregation of suspect spoil pending classification.
Practical benefits for acquisition and staged redevelopment
- Faster transaction certainty: a PSI + Section 7 search typically completes quickly and clarifies regulatory status for lenders and purchasers;
- cost control: intrusive works are reserved for sites where evidence justifies them, limiting early capex and design delay;
- compliance clarity: correct waste classification avoids unlawful disposal and expensive rework; and
- operational risk reduction: tenant management, spill controls and housekeeping reduce ongoing liabilities and insurance risk.
One‑page takeaways
- Start with a NEPM‑aligned PSI (desktop, inspection, Section 7 and council file searches, tenant lines of enquiry).
- Only escalate to DSI if site inspection or records show clear indicators (bulk fuel, staining, dumped fill, etc.).
- Require waste classification testing before spoil leaves site or is re‑used.
- Keep groundwater off‑limits until tested; confirm whether a SA EPA Groundwater Prohibition Area applies.
- Implement a written unexpected‑finds protocol that covers asbestos in soil, petroleum hydrocarbons, metals and chemical residues.
Next step: if you’re progressing acquisition or planning works, iEnvi can scope a NEPM‑aligned PSI that meets regulator, lender and developer needs. Call 13000 43684 or use our contact page: /contact/.