How Does an Auditor Think About PFAS-Impacted Sites? Auditor Insights from Past Projects

PFAS Liability Surge

Per- and polyfluoroalkyl substances (PFAS), persistent 'forever chemicals' linked to health risks including immune suppression and certain cancers, have contaminated sites across Australia primarily from historical use in firefighting foams at military bases, airports, and industrial facilities.

The landscape shifted decisively in 2025. From 1 July 2025, the Australian Government prohibited the manufacture, importation, exportation, and use of three major PFAS—PFOS, PFOA, and PFHxS—under the Industrial Chemicals Environmental Management Standard (IChEMS), closing off new intentional releases while legacy contamination persists.

Concurrently, the PFAS National Environmental Management Plan (NEMP) version 3.0, endorsed in late 2024 and published in March 2025, updated guideline values for soil, water, and biota, with a stronger push toward active treatment and remediation hierarchies that prioritize destroying or removing PFAS rather than containment or landfill disposal.

Drinking water standards tightened significantly in June 2025, with the National Health and Medical Research Council reducing health-based guideline values to PFOS at 8 ng/L, PFHxS at 30 ng/L, and PFOA at 200 ng/L—far stricter than prior levels. Estimates suggest around 73,000 Australians may have been exposed above these new thresholds, often for years, heightening community pressure and potential health claims.

These developments raise concrete stakes. Responsible parties—defence, airports, fire services, and industries—face mounting costs for investigation, monitoring, and remediation, with some projects already underway at dozens of sites and remediation expenses potentially reaching hundreds of thousands per site depending on scale. Inaction risks regulatory penalties, forced cleanups, and liabilities from affected communities or ecosystems.

A key non-obvious tension lies in the auditor's perspective: independent contaminated site auditors must sign off on assessments and plans under frameworks like the Australian Site Contamination NEPM, weighing conservative risk approaches against feasibility. Stricter guidelines amplify long-term residual risks, even after treatment, creating trade-offs between expensive advanced remediation technologies and more affordable containment—yet the NEMP 3.0's emphasis on sustainability tilts against the latter. Critics note that while bans halt new inputs, legacy plumes in groundwater can migrate indefinitely, complicating closure and perpetuating uncertainty for property owners and water utilities.