Ohio EPA deploys supercritical water oxidation to destroy 53,000 litres of legacy AFFF

Overview

The Ohio Environmental Protection Agency has successfully deployed commercial-scale supercritical water oxidation (SCWO) to destroy approximately 53,000 litres (14,000 US gallons) of concentrated legacy aqueous film-forming foam (AFFF) collected from 118 regional fire departments. The operation demonstrates that definitive, non-combustion destruction of stockpiled PFAS concentrates is now a practical reality at commercial scale, not merely a laboratory concept. For contaminated land consultants and remediation contractors, this milestone changes how we assess and recommend remedial options for PFAS source zones, stockpiled concentrates, and investigation-derived wastes.

Key details

Supercritical water oxidation works by pushing water past its critical point, specifically above 374 degrees Celsius and 221 bar of pressure. Under these conditions, water becomes a powerful solvent for organic compounds, and oxidation reactions occur rapidly and completely. The key technical aspects of the Ohio deployment include:

• Complete mineralisation: The SCWO process breaks the strong carbon-fluorine bonds that give PFAS their persistence in the environment. The end products are fluoride ions (which can be captured and managed), carbon dioxide, and clean water. This represents true destruction rather than transfer of contamination from one medium to another.
• Non-combustion process: Unlike high-temperature incineration, SCWO does not involve combustion. This eliminates the risk of incomplete destruction and the formation of products of incomplete combustion (PICs), which have been a concern with thermal treatment of fluorinated compounds.
• Commercial scale: The processing of 53,000 litres of concentrated AFFF demonstrates that SCWO can operate at volumes relevant to real-world waste management, not just bench-scale or pilot testing.
• Source collection programme: The Ohio EPA coordinated the collection of legacy AFFF stocks from 118 fire departments across the state. This type of coordinated collection and destruction programme provides a model for similar initiatives in other jurisdictions.

Australian context

Australia holds significant stockpiles of legacy AFFF, particularly at current and former Department of Defence sites, civilian airports, fuel storage facilities, and fire training grounds. The PFAS National Environmental Management Plan (PFAS NEMP 3.0) establishes the management hierarchy for PFAS-containing materials, which prioritises destruction and irreversible transformation over landfilling and long-term containment.

The Department of Defence’s PFAS Investigation and Management Program has identified dozens of sites across Australia where AFFF has been used historically. At many of these sites, stockpiled AFFF concentrates and PFAS-contaminated investigation-derived wastes require management. The availability of proven commercial-scale destruction technologies is directly relevant to these programmes.

State regulators are also increasingly focused on PFAS destruction. Key regulatory considerations include:

• Queensland: The Environmental Protection Regulation includes provisions for PFAS waste management, and the Queensland Government has invested in PFAS treatment research through partnerships with universities and industry.
• New South Wales: The NSW EPA’s regulatory framework for PFAS continues to evolve, with increasing emphasis on destruction pathways for concentrated wastes.
• Victoria: The Victorian EPA has published guidance on PFAS management, and several pilot destruction technology trials have been conducted in the state.
• Western Australia: PFAS contamination at Williamtown-adjacent sites and RAAF bases has driven regulatory attention to destruction technologies.

Currently, Australia’s onshore capacity for commercial-scale PFAS destruction is limited. Technologies being trialled or deployed include supercritical water oxidation, mechanochemical destruction (ball milling), electrochemical oxidation, and pyrolysis. The successful Ohio deployment adds further evidence that SCWO is a commercially viable option and may support business cases for establishing Australian SCWO facilities.

Practical implications

For contaminated land consultants, remediation contractors, and site owners managing PFAS contamination, the implications include:

• Remedial options assessment: The availability of proven destruction technologies expands the range of remedial options that can be included in feasibility studies and remediation action plans. SCWO should be evaluated alongside other destruction methods when assessing management options for PFAS concentrates.
• Waste management planning: Sites holding stockpiled AFFF or generating PFAS-concentrated investigation-derived wastes should include destruction pathways in their waste management plans, rather than defaulting to long-term storage or landfill disposal.
• Regulatory submissions: Demonstrating that destruction technologies are available and proven can strengthen remediation proposals submitted to state regulators for approval.
• Cost planning: While SCWO treatment costs remain higher than landfill disposal on a per-unit basis, the elimination of ongoing liability, monitoring obligations, and the risk of future regulatory tightening can make destruction the more cost-effective long-term option.
• Coordinated collection programmes: The Ohio model of collecting legacy AFFF from multiple smaller sources for centralised destruction could be replicated in Australian states, potentially through coordination between fire and rescue services, local government, and state EPAs.

References and related sources

• Original source article – WYSO
• PFAS National Environmental Management Plan (PFAS NEMP 3.0)
• Department of Defence PFAS Investigation and Management Program

How iEnvi can help

iEnvi’s contaminated land and remediation specialists have extensive experience managing PFAS-contaminated sites across Australia. We provide PFAS site investigations, human health and ecological risk assessments, remediation feasibility studies, and remediation action plan development. Our team works with the latest PFAS destruction and treatment technologies to design management strategies that align with the PFAS NEMP hierarchy and state regulatory requirements. For complex PFAS matters requiring independent technical opinion, our expert witness team can provide support for litigation and regulatory proceedings. Contact iEnvi to discuss your PFAS investigation and remediation needs.

This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

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