Baseline Environmental Condition Investigation – Western Melbourne Bus Depot

The issue

An established bus depot in western Melbourne, Victoria, required a Baseline Environmental Condition Investigation (BECI) to meet Department of Transport & Planning expectations for continuing depot operations. Adjacent historic investigations had found petroleum hydrocarbons and asbestos in nearby land, creating a need to confirm whether refuelling, bus wash and maintenance activities had affected soil or groundwater on this property.

What we did

iEnvi carried out a targeted, regulator-focused investigation and compliance audit. Scope delivered for the western Melbourne depot included:

• site inspections and compliance audits of depot operations;
• installation of 10 new soil bores and associated bore logging;
• installation of groundwater monitoring wells and groundwater sampling;
• targeted soil and groundwater laboratory testing for: petroleum hydrocarbons, heavy metals, PFAS (Per- and Poly‑Fluoroalkyl Substances), nutrients, and asbestos in soil;
• consolidated Environmental Site Assessment reporting suitable for regulators and land‑transaction due diligence.

Key findings

• No significant contamination requiring remediation was identified at the depot.
• Only minor, naturally occurring background concentrations of some metals were recorded in soil.
• Reported groundwater concentrations of copper and nickel were interpreted as geogenic (natural) rather than resulting from depot activities — the site conceptual model and local geology supported this interpretation (see notes about verification below).
• PFAS and nutrient concentrations were well below relevant screening thresholds used for investigation and risk assessment.

Regulatory context and benchmarking

Investigations were benchmarked to the nationally‑accepted site assessment framework and jurisdictional guidance used in Victoria. Reporting and the assessment approach were prepared to align with the national assessment framework for contaminated sites and current PFAS assessment guidance. The BECI and consolidated reports provide a documented basis for compliance with obligations under Victoria’s Environment Protection Act 2017, including the requirement to manage risks to human health and the environment as far as reasonably practicable.

Recommendations

• No remediation works were required for the depot based on the investigation results.
• Preparation and implementation of a Fuel System Operating Plan (FSOP) was recommended to formalise operational controls for refuelling and reduce ongoing risk and compliance exposure.
• Maintain a simple groundwater monitoring program and retain laboratory certificates and chain‑of‑custody documentation for future audits or property transactions.

Practical takeaways for owners, operators and purchasers

1. Targeted, risk‑based sampling reduces unnecessary cost: focusing on likely pathways (refuelling areas, wash bays, tank locations) and using a defensible conceptual site model provides cost‑effective assurance.
2. Operator controls such as an FSOP are often a lower‑cost way to manage residual operational risks than large‑scale remediation when investigations show no significant contamination.
3. Well‑documented, NEPM‑aligned reporting and clear monitoring records materially reduce transaction and regulatory risk during sale, lease or audit processes.

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Next steps & contact

If you operate transport or heavy‑vehicle facilities, a proportionate BECI and straightforward operational controls (for example an FSOP) will reduce environmental and commercial risk while keeping costs down. Contact our contaminated‑land and groundwater specialists for a pragmatic site review and tailored scope.

Call 13000 43684 or contact us to discuss a site assessment or compliance audit.