Engineering challenges often dominate the conversation around offshore decommissioning in Perth. However, in our experience, hazardous waste management is one of the most critical and underestimated elements of a successful decommissioning program.
From residual hydrocarbons and toxic coatings to contaminated marine growth and legacy electrical components, offshore assets contain a wide range of hazardous materials.
They must be identified, isolated, and managed correctly to prevent serious risks to people and the environment. And, in turn, project schedules and long-term compliance.
In Western Australia, the hub of Australia’s offshore decommissioning activity, regulators and stakeholders are increasingly turning their attention to hazardous waste handling.
Why Hazardous Waste Is a Defining Challenge in Offshore Decommissioning
Offshore oil and gas infrastructure, including fixed platforms, pipelines, and FPSO (floating production, storage, and offloading) vessels, can be in operation for decades.
Many facilities were designed before modern safety standards were introduced. They may be improperly maintained or contain unrecorded hazardous chemicals.
This infrastructure is also remote, located in harsh seas hundreds of kilometres offshore. Exposure to saltwater accelerates corrosion, while weather conditions add uncertainty during lifting and transport operations.
Unlike onshore projects, managing hazardous waste in oil and gas decommissioning requires an integrated approach to safety, environmental protection, regulatory compliance, and technical innovation.
Poor handling carries serious risks:
- Exposing workers to toxic substances
- Contaminating marine ecosystems
- Delaying projects
- Creating long-tail liabilities that persist well beyond asset removal
In an industry facing heightened scrutiny from regulators, investors and the public, hazardous waste management has become a core measure of operator competence and ESG performance.
What Counts as Hazardous Waste in Offshore Decommissioning?
Offshore structures typically contain a broad spectrum of hazardous materials that accumulate over years and decades. These often include:
- Residual hydrocarbons such as oils, fuels, and sludges trapped in infrastructure
- Chemicals used during production, including corrosion inhibitors, solvents, and cleaning agents
- Lead-based paints, asbestos insulation, and polychlorinated biphenyls (PCBs) found in older infrastructure
- Mercury in legacy instrumentation
- Batteries, cabling, and electronic waste
Unfortunately, materials inventories are often incomplete or outdated. As a result, hazardous substances are sometimes discovered only once dismantling begins.
One of the less visible but still significant hazards is contaminated marine growth. Barnacles and shells can absorb hydrocarbons and heavy metals, creating both contamination and biosecurity risks when structures are brought onshore.
Regulatory Expectations in Australia and Western Australia
NOPSEMA: National Governance
The National Offshore Petroleum Safety and Environmental Management Authority, or NOPSEMA, governs oil and gas operations in Commonwealth waters.
Under the Offshore Petroleum and Greenhouse Gas Storage Act 2006, NOPSEMA requires operators to submit Environment Plans that identify hazards, assess risks, and demonstrate how impacts will be reduced to as low as reasonably practicable. These plans must address waste handling, transport, disposal, and monitoring.
NOPSEMA expects clear accountability from offshore removal through to final onshore processing. Reporting and record-keeping obligations are central to this process for traceability and regulatory oversight.
The Environmental Protection (Sea Dumping) Act 1981 can also impose conditions for safe material handling and penalties for pollution events.
DMPE: Regulating Oil and Gas Decommissioning in Perth and WA
Once materials reach shore, state and federal waste legislation applies.
In Western Australia, the Environmental Protection Act 1986 imposes strict duties of care for hazardous waste handling, transport, and disposal.
For example, only licensed facilities and transporters may process certain waste streams. However, operators remain responsible for compliance throughout the chain of custody.
Navigating these regulations is not easy. As an experienced oil and gas decommissioning consultant, we can help you understand your requirements and plan for compliance.
International Best Practices
Oil and gas activity is unique in that it is subject to international guidelines. In fact, there are several conventions, policies, and protocols that overlap with Australian and state-based regulations.
You can learn more about the complex oil and gas regulation landscape at NOPSEMA’s website.
The Risks of Poor Hazardous Waste Management
Poor hazardous waste management undermines an entire offshore decommissioning project. The risks extend well beyond compliance. They have decades-long environmental, safety, and financial consequences.
Environmental Impacts
Inadequate controls increase the likelihood of:
- Marine contamination from hydrocarbons and chemicals
- Long-term damage to sensitive seabed and coastal ecosystems
- Pollutants spreading beyond the original project footprint
Once contamination occurs offshore, remediation is complex, costly, and often difficult to fully reverse.
Safety Risks
Hazardous materials also present serious risks to people involved in removal and dismantling activities. These include:
- Exposure to toxic substances
- Fire or explosion risks from residual hydrocarbons
- Structural instability when cutting or lifting contaminated assets
These dangers are amplified when hazardous materials are not identified early or are allowed to mix with general scrap streams.
Financial and Legal Exposure
The commercial consequences can also be severe. Poor waste management can result in:
- Regulatory penalties and stop-work orders
- Costly clean-up and remediation programs
- Long-term liabilities and reputational damage
In some cases, liabilities can persist years after project completion, particularly where waste has been misclassified or disposed of incorrectly.
Best Practice Approaches to Hazardous Waste Management
To prevent as many of these risks as possible, hazardous waste management cannot be treated as an afterthought. It must be built into decommissioning programs from the outset.
Early Planning and Waste Audits
Best practice starts well before offshore removal begins. Detailed waste audits allow operators to identify and assess hazardous materials, and create long-term waste minimisation strategies.
Controlled Removal and Segregation
Hazardous materials must be isolated using specialist equipment and procedures. Once onshore, segregation is critical. Chemicals, oils, contaminated metals, and general scrap must be stored separately.
Compliant Transport, Disposal and Recycling
Hazardous waste must be transported by licensed providers, supported by clear chain-of-custody documentation, and delivered to approved facilities.
Wherever possible, recycling should be prioritised – particularly for metals, batteries and recoverable components. Recycling not only reduces landfill reliance but also delivers measurable commercial benefits and improves sustainability in oil and gas decommissioning.
Why a Specialist Partner Makes the Difference
Hazardous waste management in offshore decommissioning in Perth demands specialist expertise, not generalist waste handling.
Contamination risks are tightly regulated. Safe and responsible handling requires experienced personnel, certified systems, and purpose-built facilities.
C.D. Dodd has invested specifically to meet these challenges in Western Australia.
- Custom-designed flowline and umbilical processing equipment reduces manual handling, improves safety, and enables efficient dismantling offshore
- Purpose-built facilities located near Ashburton and Dampier ports, including a controlled decontamination facility at Onslow, provide efficient onshore processing
- Our local workforce and facilities are designed to minimise community impact and support ESG goals
With more than 50 years of experience and an uncompromising approach to safety and compliance, C.D. Dodd gives operators confidence that hazardous waste is managed correctly throughout decommissioning.
Contact C.D. Dodd to handle hazardous waste safely and efficiently for your next offshore decommissioning project.