PFAS Solutions: How Are We Tackling These Forever Chemicals :Engineering Institute of Technology

Australia’s current management plan for per- and polyfluoroalkyl substances (PFAS) provides the local backdrop for understanding how engineering professionals detect contamination, treat water, manage polluted soil and handle the waste left behind.

PFAS are often called “forever chemicals” because many of them barely break down in nature. That durability once looked like a major advantage. It made products resistant to heat, grease and water. PFAS were added to firefighting foams and used in industrial processes, along with many everyday goods.

The problem begins when those chemicals escape. PFAS can seep from soil into groundwater and move into nearby waterways. Cleaning up a spill years later is far harder than containing it when it happens.

Australia’s main guide for this work is the PFAS National Environmental Management Plan (NEMP) 3.1. It gives regulators and engineering professionals a shared framework for investigating contaminated sites and handling PFAS waste. The response depends on what could be exposed.

Finding Contamination Without Adding More

Engineering professionals first work out where the PFAS came from and where it may have gone. At a former firefighting training area, groundwater may carry pollution beyond the original release point.

Sampling sounds straightforward. PFAS makes it unusually fussy. Waterproof clothing, sunscreen, and some food packaging may contain the same chemicals being measured. Teflon parts on sampling equipment can also affect results. The NEMP’s sampling guidance calls for carefully selected equipment and blank samples that can reveal accidental contamination.

Back in the laboratory, instruments measure a set list of known PFAS. Thousands of PFAS exist, and one test cannot see them all. A method called the total oxidizable precursor assay can indicate whether other PFAS-related chemicals are hiding in the sample. It gives a broader warning, though it cannot name every compound.

Taking PFAS Out of Water

Ordinary water-treatment plants do not remove PFAS very well. Engineering professionals often add a separate treatment stage using granular activated carbon or ion-exchange resin.

Activated carbon works a little like a sponge. PFAS sticks to its large internal surface while water passes through. It is generally better at catching older, long-chain compounds such as PFOS and PFOA. Smaller short-chain PFAS can pass through sooner.

Ion-exchange systems use small resin beads that attract charged PFAS molecules. They can hold more of some compounds, although the resin eventually fills up. Another option is reverse osmosis, which forces water through a very fine membrane. This can achieve strong removal, but it uses considerable pressure and energy.

Every one of these systems leaves something behind. Used carbon and resin contain the captured PFAS. Reverse osmosis produces a smaller volume of water with a much higher concentration. Engineering professionals must plan where these wastes will go before the treatment plant starts operating.

What Happens When the Soil Is Contaminated?

PFAS-contaminated soil cannot be handled as ordinary construction spoil. Australia uses the waste code M270, and the NEMP identifies the material as Class 9 dangerous goods. Loads must be described and tracked under the rules of the relevant state or territory.

Even a temporary stockpile needs thought. A cover keeps rain from soaking through the pile. A liner helps stop contaminated water from reaching the ground. Drainage may need to be captured and tested.

Landfills face the same water problem. Rainwater passing through waste creates leachate, which can carry PFAS into a wastewater plant. Treatment then produces another concentrated residue. The waste has changed form, but it still needs a secure destination.

Why There Is No Simple PFAS Fix

Workers inspecting wastewater treatment facility for PFAS

Current technology can remove many PFAS from water and slow their movement through soil. Destruction at a useful commercial scale remains difficult. Some promising methods are still being tested, while others consume too much energy for routine use. Short-chain PFAS are especially mobile and can be harder to capture.

CSIRO is investigating better detection and new ways to break PFAS down. Any new process will need to prove that it works on real sites, where water contains other chemicals and contamination varies from day to day.

This work crosses several areas of engineering. A PFAS project might involve groundwater movement, water-treatment equipment and the safe storage of excavated soil. Engineering professionals need enough breadth to understand how one decision affects the next.

EIT’s 52925WA Graduate Certificate in Water Resources Engineering* builds knowledge in the assessment and management of water systems. Its Professional Certificate of Competency in Sewage and Effluent Treatment Technologies is more closely focused on treatment plants and operational problems. These are useful foundations for engineering professionals moving into water quality or contaminated-site work.

PFAS has no single engineering fix. Each treatment leaves a new question: where did the chemicals go next? The success of a cleanup depends on having a convincing answer.