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Oregon’s Game-Changer for “Forever Chemicals”: Understanding DEQ-28-2025

By November 3, 2025 No Comments

On September 12, 2025, the Oregon Environmental Quality Commission adopted Administrative Order DEQ-28-2025, updating OAR 340-122-0115(30) to include six specific per- and polyfluoroalkyl substances (PFAS) as “hazardous substances” under the state’s Cleanup Law. This rule gives the Oregon Department of Environmental Quality (DEQ) explicit authority to investigate, require cleanup, and enforce remediation when PFAS are released into the environment.

PFAS—known as “forever chemicals”—have been used for decades in waterproof coatings, non-stick cookware, firefighting foams, and industrial processes. Their chemical stability makes them useful but also persistent in soil and groundwater, where they resist breakdown and can accumulate over time. Exposure to certain PFAS has been linked to increased cholesterol, developmental issues, immune suppression, and some cancers.

What’s Changing

Before DEQ-28-2025, Oregon’s ability to compel cleanup of PFAS contamination was limited or legally ambiguous. The new rule closes that gap by naming six specific compounds now regulated as hazardous substances:

  • Perfluorooctanoic acid (PFOA)

  • Perfluorooctanesulfonic acid (PFOS)

  • Perfluorohexane sulfonic acid (PFHxS)

  • Perfluorononanoic acid (PFNA)

  • Hexafluoropropylene oxide dimer acid (HFPO-DA, “GenX Chemicals”)

  • Perfluorobutane sulfonic acid (PFBS)

This designation empowers DEQ to investigate PFAS-impacted sites, require responsible parties to take remedial actions, and treat PFAS releases with the same seriousness as other hazardous substances.

Why It Matters

The adoption of DEQ-28-2025 aligns Oregon with EPA’s 2024 National Primary Drinking Water Regulation for PFAS and other emerging state-level initiatives. More importantly, it extends Oregon’s cleanup authority beyond drinking water—reaching contaminated soil, groundwater, and site remediation.

The implications are wide-ranging:

  • Expanded cleanup liability: Owners, operators, and potentially prior landholders at sites with historical PFAS use may now fall under DEQ’s cleanup authority.

  • Increased due-diligence obligations: Environmental consultants will need to consider PFAS screening during Phase I and II ESAs to ensure compliance with the updated state definitions.

  • Stronger regulatory alignment: The six PFAS covered by Oregon’s rule mirror those under EPA’s enforceable Maximum Contaminant Levels (MCLs), reinforcing consistency across state and federal programs.

  • Broader policy momentum: Oregon’s rule is part of a growing suite of PFAS controls—including bans on PFAS-containing foodware (effective 2025), firefighting foams (effective 2026), and cosmetics (effective 2027).

Who’s Impacted

Several sectors are most likely to feel the effects of DEQ-28-2025:

  • Property owners and developers with historical industrial, manufacturing, or fire-training operations should evaluate potential PFAS liabilities.

  • Environmental professionals should integrate PFAS sampling into their investigation and remediation strategies.

  • Public water systems and utilities may see overlapping regulatory actions as Oregon aligns with EPA’s drinking-water standards.

  • Manufacturers and suppliers that use PFAS in production should prepare for increased scrutiny and possible reformulation requirements.

What to Do Next

If your organization operates or owns property in Oregon, now is the time to take proactive steps:

  1. Conduct a PFAS inventory – Identify any historical or current uses of the six listed compounds.

  2. Review existing environmental data – Determine whether PFAS sampling has been performed and whether concentrations may exceed DEQ or EPA screening levels.

  3. Integrate PFAS into due diligence – For property transactions, ensure that Phase I and Phase II ESAs include PFAS considerations where relevant.

  4. Plan for remediation contingencies – Facilities with known or potential releases should prepare site-specific cleanup strategies.

  5. Stay current on guidance – DEQ is expected to issue additional technical and enforcement guidance following DEQ-28-2025’s adoption.

Looking Ahead

Although DEQ-28-2025 currently applies to six PFAS compounds, this is likely just the beginning. As scientific understanding evolves, Oregon and other states are expected to expand their hazardous-substance lists and tighten exposure thresholds. The rule underscores a broader national trend toward treating PFAS contamination with the same rigor as other hazardous-waste issues.

For Oregon’s environmental community—consultants, property owners, and public agencies alike—this regulation is both a challenge and an opportunity: a challenge to adapt quickly, but an opportunity to lead in sustainable, defensible environmental management.

McAlister GeoScience is actively monitoring Oregon’s PFAS regulatory developments and assisting clients in adapting to DEQ-28-2025. If you manage sites with historical industrial activity, conduct property due diligence, or suspect PFAS impacts, reach out to our team for support in navigating sampling, risk assessment, and cleanup requirements.

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