From Regulation to Reality: How Australia’s Proposed PFAS Standards Could Transform Drinking Water Management

Aurecon 's multidisciplinary experts, Sally Williamson , Farhana Allie and Matthew Tendam came together to discuss the implications of the recently proposed changes to PFAS drinking water thresholds in the Australian Drinking Water Guidelines.

What are PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4,700 chemicals used in various products, including firefighting foams, food packaging, cosmetics, medical devices, and industrial applications. Sometimes referred to as “forever chemicals”, their stability (due to the carbon-fluorine bond) makes them highly persistent in the environment, and long-term exposure poses health risks. Additionally, PFAS bioaccumulate and biomagnify throughout food chains, contributing to their concern. Drinking water is one of the human exposure pathways, particularly in communities near military bases, firefighting grounds, and areas where water bodies were previously exposed to PFAS contamination. Exposure through consumer products, dietary habits, and household dust are the most common pathways for communities not exposed to PFAS contaminated waters.

In Australia, PFAS levels in drinking water are regulated by the Australian Drinking Water Guidelines (ADWG), overseen by the National Health and Medical Research Council (NHMRC). In October 2024, the NHMRC released draft updates to the ADWG for public consultation, proposing new PFAS thresholds, with final recommendations expected in April 2025.The proposed NHRMC drinking water guidelines are summarised in the table below.

Why the Change?

Globally, nine countries and the European Union (EU) have set limits for PFAS in drinking water. Two approaches have emerged: regulating PFAS individually or as a class. Australia, the U.S., and several European nations regulate individual PFAS, while Canada and the EU use a class-based approach. For example, Canada caps total PFAS at 30 ng/L for 25 specified compounds, whereas the EU limits are set at 500 ng/L for a broader range of PFAS. Additionally, countries adopt varying methodologies to set limits suited to their risk-based approach and local context. The recent proposed changes to the ADWG bring the Australian limits more in line with those set internationally.

What are the Regulatory Challenges?

In the U.S., the Environmental Protection Agency (US EPA) has recently introduced stringent thresholds for PFOS and PFOA, setting both at 4 ng/L with a maximum contaminant goal of zero. Other PFAS, such as PFNA and PFHxS, are also regulated, with water utilities required to comply within five years. The U.S. thresholds represent the lowest detectable limits, which present technical challenges as "zero" concentrations cannot be measured. In comparison, the EU has adopted more lenient thresholds for a broader range of PFAS, while Canada is guided by reducing concentrations to as low as reasonably achievable (ALARA) through established treatment practices. Australia, however, bases its regulations on health-based guidance and considers the effects of long-term exposure through drinking water.

The debate over regulating PFAS individually or as a class remains unresolved. Regulating PFAS as a class accounts for uncertainty regarding the toxicity of individual compounds and mixtures. However, this approach may be overly conservative, as thousands of PFAS have distinct chemical and physical properties. On the other hand, regulating PFAS individually allows for targeted management based on established toxicity, but it does not fully adhere to the precautionary principle, given the time required to assess each compound’s effects.

How is Drinking Water Quality Management Impacted?

The proposed changes to the ADWG could have several implications for water utilities. The ubiquity of PFAS makes it difficult for drinking water managers to manage contamination they did not cause and for which they are not responsible. While responsible for providing safe water, utilities may face lengthy and complex processes to recover costs from the industries responsible for PFAS contamination. And all the while they are still required to plan for and fund efforts to comply with the lower proposed PFAS drinking water thresholds.

1. Infrastructure Upgrades: Water treatment plants may require augmentation to meet the new PFAS thresholds, imposing significant costs on utilities, which could be passed on to consumers.
2. Increased Monitoring: More frequent PFAS monitoring would lead to higher operational costs for water utilities.
3. New Compounds: The inclusion of PFBS in the guidelines presents uncertainties, as this compound has not been consistently monitored in Australian water supplies.
4. Future-Proofing: Utilities may need to prepare adaptive management strategies for further regulatory changes, potentially expanding to cover more PFAS or an entire class.
5. Reputational Risk: Exceeding the current or proposed PFAS limits could damage the reputation of water utilities, particularly in areas already impacted by contamination.

What are the Challenges Likely to be Faced?

There are unique challenges related to monitoring and regulating PFAS in drinking water for both large and small water utilities. Potential challenges relate to external technical factors and internal capability factors and include the following:

Technical Challenges:

• Limited Data: Most PFAS have limited toxicity data, complicating efforts to regulate them individually. Laboratories can only reliably detect around 40 PFAS compounds to varying levels of accuracy and detection limits, contributing to significant uncertainty about the health impacts of others.
• Limited Treatment Technologies: Only a few established technologies can effectively remove PFAS to meet the proposed ADWG thresholds. Several emerging technologies are available but come at significant investment and complexities with demonstrating the effectiveness of these technologies. Cost-benefit analyses and multi-year timelines will be required to implement feasible treatment options.
• Detection limitations: PFAS are already very difficult to measure accurately, due to their ubiquitous nature. Thus, analytical methods will need to be improved so that detections limits are at least as low as the guideline limits, whilst minimising the chance of false positives.

Capability Challenges: Smaller drinking water management entities, especially in regional areas, may lack the resourcing, funding and technical capacity to monitor and treat PFAS contamination.

• Financial Constraints: Smaller drinking water managers are likely to face funding issues to address expensive upgrades and monitoring programs required for PFAS compliance. Additionally, access to analytical laboratories equipped to undertake the required testing will provide costly constraints.
• Workforce Limitations: Increasing PFAS monitoring and implementation of adaptive management programs will strain an already stretched workforce, particularly for drinking water managers without the necessary expertise.

So What?

The proposed updates to the Australian Drinking Water Guidelines for PFAS represent a shift toward stricter regulation, aligned with global trends. While this brings Australia closer to international standards, it also presents significant technical, financial, and operational challenges for drinking water managers. The debate over how PFAS is regulated, whether as individual compounds versus as a class continues, and water utilities will need to adapt to evolving regulations while ensuring public safety.