When PFAS shows up in a drinking water source, decisions need to be fast and defensible
Emerging contaminants are changing what “secure supply” means for water operators and communities. In Katherine, Northern Territory, historical use of aqueous film forming foam (AFFF) at RAAF Base Tindal led to per- and polyfluoroalkyl substances (PFAS) groundwater contamination in the Tindal aquifer. That aquifer supports the Northern Territory Power and Water Corporation (PWC) Katherine Water Treatment Plant, which supplies a community of about 10,000 people.
Katherine relies primarily on surface water from the Katherine River, with groundwater used to meet peak demand and provide backup capacity. Once PFAS was identified in the supply, the team needed an immediate solution that protected public confidence while building a longer-term strategy that could keep pace with tightening drinking water expectations.
A rapid response system that treated real water under real constraints
The first requirement was speed. Defence agreed to provide a treatment system, and the project team needed a proven technology that could be fabricated, shipped, installed and commissioned quickly in a remote location.
Onterris partnered closely with Defence and PWC to finalize the design and deliver an interim treatment system within four months of PFAS being identified. The interim plant supplied 1 megalitre per day (ML/d), about 10% of Katherine’s daily water demand, and provided a stable bridge while the team planned full-scale treatment.
The interim system paired pretreatment filtration for solids and co-contaminants with PFAS removal using proprietary SORBIX™ ion exchange (IEX) resins. The team built the system in the United States, packaged it in international shipping containers to support efficient transport and pre-shipment adjustments, then moved it to Australia. Defence accelerated delivery by air-freighting the system to Darwin on an Antonov An-124, followed by a 330-kilometre road move to Katherine. The interim plant went online in late October 2017 and treated more than 2.3 billion liters of water by March 2024.
Projects like this demand rigor and speed at the same time. We started in the lab, then carried that learning into a field-ready system that protected the drinking water supply while reducing waste and keeping future requirements in view.
Scaling from interim protection to full-town capacity, without reinventing the process
To secure long-term supply for Katherine, PWC engaged Onterris to design and deliver a full-scale treatment system capable of processing 10 ML/d. The goal was clear: cover full town demand when surface water is unavailable, whether due to maintenance or extreme weather, and build operational resilience into the facility.
The 10 ML/d plant uses the same proven treatment approach as the interim system, including pretreatment filtration and PFAS removal with SORBIX™ IEX resin. Regenerating resin after adsorption capacity is reached reduces waste generation and supports efficient lifecycle operation as PFAS requirements evolve.
The team designed the plant as three independent streams capable of processing 5 ML/d per stream, creating one redundant stream. That configuration supports maintenance without sacrificing current peak demand performance. Commissioning was completed in November 2023. After a successful three-month performance test period, the team shut down the interim plant in March 2024 and proceeded with decommissioning.
A model for remote communities managing emerging contaminants
The Katherine PFAS Water Treatment Plant demonstrates what strong emerging contaminant management looks like in practice: integrated teams, science-led design choices, proven treatment technology and lifecycle planning that reduces waste while keeping performance resilient. Recognition followed, including an Australasian Land and Groundwater Association Industry Excellence Award in 2019 and a 2024 Northern Territory Water Awards win for infrastructure project innovation.
Today, the full-scale system stands as Katherine’s long-term safeguard and a repeatable model for utilities facing PFAS in critical water sources, especially where geography and logistics leave little room for trial and error.