Drinking Water Treatment Plant in Katherine, Australia: From 1 ML/d Interim System to 10 ML/d Full Scale System

Solution

The interim treatment system included a pre-treatment filtration to remove solids and other co-contaminants, prior to the PFAS removal with ECT2’s proprietary  SORBIX^TM  ion exchange (IEX) resins. The system was manufactured in ECT2’s central fabrication shop in Maine and installed in international shipping containers for easy transportation across the globe. This approach facilitated operational adjustments prior to shipment and translated to faster on-site readiness. Defence further accelerated the delivery scheduled through air-freighting the system in an Antonov An-124 transport plane to Darwin, Australia, where it was then transported approximately 330 kilometres by road to Katherine. The interim 1 ML/d water treatment system went online in late October 2017, and by March 2024, had treated over 2.3 billion litres of water.

To meet long-term water supply requirements for the Katherine community, Power & Water Corporation engaged ECT2 to design a treatment system with the capacity to process 10 ML of water per day in order to supply the entire town water demand in situations where surface water cannot be supplied, whether due to maintenance at the surface water plant, or due to extreme weather. The 10 ML/d plant was also designed with 50% additional redundant capacity to increase the volume, if necessary.

The full scale 10 ML/d treatment system utilises the same proven process as the initial interim system, pre-treatment filtration to remove solids and other co-contaminants, prior to the PFAS removal with ECT2’s proprietary SORBIX^TM  ion exchange (IEX) resin. The ability to regenerate the resin once PFAS adsorption levels are reached results in a significant reduction in waste generated from the plant.

The plant has been designed and built as three independent streams capable of processing 5 ML/d per stream, resulting in one redundant stream, providing the ability to perform maintenance even when operating at current peak demand. The plant performance comfortably exceeds the requirements of the Australian Drinking Water Guidelines and is well placed to satisfy any potential future tightening of these guidelines, as the ability to regenerate the SORBIX^TM resins future proofs the plant operation at any level of PFAS regulation.

This was a unique project in Australia in both the scale of the plant and the execution of this project in a remote part of the Australian continent. The result ensures that the people of Katherine will have a secure and safe water supply for many years into the future.

The 10 ML/d plant was commissioned in November 2023. Following successful completion of a three-month performance test period for the full-scale plant, the interim plant was shut down in March 2024, and subsequently decommissioned.