Filtration fix for troubled waters
Sydney Water is tackling ‘forever chemicals’ in a local waterway with a mobile treatment solution.
A new mobile treatment system is helping Sydney Water overcome recent water quality challenges in the Blue Mountains.
The organisation commissioned the upgrade for the Cascade Water Filtration Plant late last year after elevated levels of per- and polyfluoroalkyl substances (PFAS) were discovered in June.
These synthetic compounds - also known as ‘forever chemicals’ - have been linked to serious health conditions such as cancer. At the Cascade plant, two forms of PFAS - perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonic acid (PFHxS) - were detected.
The new treatment system was developed by Montrose Environmental Group, a US-based company that specialises in treating PFAS-impacted water and has operations in Australia.
Its solution uses a dual-technology approach, combining granular activated carbon (GAC) and ion exchange (IX) resin to reduce PFAS levels in drinking water.
As researchers worldwide race to combat toxic contaminants like PFAS, methods like Granular Activated Carbon (GAC) and Ion Exchange (IX) are offering practical solutions for purifying drinking water (see box).
"It is important that communities are confident in the knowledge that they have access to safe and secure water, and this new technology will help us in those efforts."
Although the current PFAS levels at the Cascade Water Filtration Plant are compliant with current Australian Drinking Water Guidelines, Sydney Water said the new treatment system was developed to comply with stricter limits expected to be introduced later this year.
These new standards are being overseen by the National Health and Medical Research Council (NHMRC) and are due to be finalised in April. From there they are expected to be implemented by states and territories.
Sydney Water said the mobile Montrose system began operating in late 2024, with water quality results expected to be shared early this year. It confirmed that it would continue to collaborate with NSW Health to monitor and manage PFAS levels across its network, maintaining compliance with existing guidelines at Cascade WFP.
Sydney Water's Managing Director Roch Cheroux said: "This initiative reinforces Sydney Water's promise to deliver safe, clean, and reliable water to all our customers.”
NSW Minister for Water, Rose Jackson, added: “It is important that communities are confident in the knowledge that they have access to safe and secure water, and this new technology will help us in those efforts.”
PFAS are persistent, residual chemicals that can leach from industrial processes and household products to contaminate soil, surface water, and groundwater. Methods for removing them are the subject of much scientific research. Granular activated carbon (GAC) and ion exchange (IX) resin are two approaches that are gaining traction for treating contaminated water. GAC is a very porous carbon-based material that can target long-chain PFAS compounds and volatile organic compounds (VOCs). Ion Exchange (IX) Resin can remove short-chain PFAS using a process that exchanges harmful ions with harmless ones.
