PFAS in Drinking Water

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic chemicals used for their water-, oil-, and stain-resistant properties. They have been widely used in industrial processes and consumer products since the 1950s.

PFAS are often called “forever chemicals” because they break down extremely slowly in the environment and can accumulate in water, soil, wildlife, and human tissue.

Drinking water has become one of the most common exposure pathways.

A precautionary, structured approach to understanding and reducing exposure is reasonable.

What Are PFAS?

PFAS are a family of thousands of fluorinated chemicals used in products such as:

• Non-stick cookware
• Waterproof clothing
• Food packaging
• Fire-fighting foams
• Industrial coatings
• Stain-resistant fabrics

Two of the most widely studied PFAS are:

• PFOA (Perfluorooctanoic acid)
• PFOS (Perfluorooctane sulfonate)

Many countries have phased out these compounds, but replacement PFAS chemicals remain in use, and many older contaminants persist in the environment.

Because PFAS are extremely stable, they can circulate through water systems for decades.

How PFAS Enter Drinking Water

PFAS contamination of water sources usually occurs through industrial and environmental release.

Common pathways include:

• Fire-fighting foam used at airports and military bases
• Industrial manufacturing discharge
• Landfill leachate entering groundwater
• Wastewater treatment plant discharge
• Contaminated soil runoff into rivers and reservoirs

Once in groundwater or surface water, PFAS can move through water systems and eventually reach municipal drinking water supplies or private wells.

PFAS in Australian Drinking Water

PFAS contamination has been documented in several regions across Australia, particularly near sites where fire-fighting foams were historically used.

Notable areas investigated include:

• Williamtown (NSW)
• Oakey (QLD)
• Katherine (NT)

Testing in some affected regions has found PFAS levels in groundwater and surface water above guideline values, leading to remediation programs and long-term monitoring.

Australia regulates PFAS in drinking water through guideline values established by the National Health and Medical Research Council (NHMRC).

Current Australian drinking water guideline limits include:

• PFOS + PFHxS: 70 ng/L
• PFOA: 560 ng/L

These values are designed to limit long-term exposure through drinking water.

However, regulatory limits vary internationally and continue to evolve as research develops.

Potential Health Concerns

Research into PFAS exposure is ongoing, but several associations have been reported in epidemiological and laboratory studies.

Long-term PFAS exposure has been linked to:

• Changes in cholesterol levels
• Immune system effects
• Thyroid hormone disruption
• Developmental effects during pregnancy
• Increased risk of certain cancers in highly exposed populations

Most research focuses on high exposure communities or occupational exposure, and the relevance to low-level background exposure remains an active area of scientific investigation.

Nevertheless, PFAS bioaccumulate, meaning small exposures over time can build up in the body.

Water Testing for PFAS

PFAS cannot be detected by taste, smell, or appearance.

Testing requires specialised laboratory analysis capable of detecting PFAS at extremely low concentrations.

Testing is generally recommended when:

• Living near known PFAS contamination sites
• Using private bore or well water
• Living near airports, military bases, or industrial sites
• Investigating unexplained environmental contamination

Most municipal water systems conduct periodic testing, but results may not always be easily accessible to residents.

Filtration Options for PFAS Removal

Certain household water filtration technologies can significantly reduce PFAS concentrations.

The most studied options include:

Reverse Osmosis (RO)

Reverse osmosis systems force water through a semi-permeable membrane that can remove many dissolved contaminants.

RO systems are capable of removing a wide range of PFAS compounds and are commonly used in under-sink drinking water systems.

Activated Carbon Filters

Granular activated carbon (GAC) filters can adsorb many PFAS compounds.

Effectiveness depends on:

• Carbon type
• Filter size
• Contact time
• Filter replacement frequency

Large carbon filters generally perform better than small cartridge filters.

Combination Systems

Some filtration systems combine carbon filtration and reverse osmosis, providing broader contaminant removal.

Filter performance varies by product and by the specific PFAS compounds present.

Regular maintenance and filter replacement are essential for consistent performance.

Practical Exposure Reduction

For households concerned about PFAS exposure:

• Review local water quality reports
• Consider independent water testing if using private water sources
• Use certified filtration systems designed for PFAS removal
• Replace filters according to manufacturer guidelines

Reducing PFAS exposure from water is one part of a broader strategy, as PFAS can also be present in food packaging, dust, and consumer products.

Summary

PFAS are persistent environmental chemicals that have entered water systems worldwide through industrial use and environmental contamination.

While research continues to clarify long-term health impacts, reducing unnecessary exposure — particularly through drinking water — is a reasonable precaution.

Testing and appropriate filtration technologies can help households better understand and manage potential exposure.