Fonterra Edendale RO-EDI Boiler Feedwater Plant
Southland, New Zealand

Client
Plant Capacity
Technology
Source Water
Quality Issue
High-Purity Boiler Feedwater System at Fonterra Edendale
Fonterra required a high-purity water treatment system to support a new electrode boiler at its Edendale site. The system needed to consistently achieve ultra-low conductivity feedwater while integrating with site automation and minimising operator intervention.
FILTEC designed and delivered a dual-train reverse osmosis and electrodeionisation (RO–EDI) system producing 32 m³/h of high-purity water with >99% availability. The plant supports reliable boiler operation, reduced maintenance and consistent steam production.
High-Purity Feedwater for Electrode Boiler Performance
Fonterra’s Edendale site required a new high-purity water system to supply its new electrode boiler, which demands exceptionally low-conductivity feedwater to operate efficiently and avoid scaling or corrosion. To ensure reliable steam production and equipment protection, Fonterra needed a robust, low-maintenance reverse osmosis and EDI solution capable of continuous operation and easy integration with the site’s automation systems.

High-Efficiency RO–EDI Design for Boiler Feedwater
FILTEC designed a dual-train high-purity water treatment system based on Xylem reverse osmosis and electro-deionisation technology. Each train produces 16 m³/h, providing a combined capacity of 32 m³/h at over 99 percent availability. The system achieves final water quality of < 0.06 µS/cm conductivity and < 0.01 mg/L silica, ensuring consistent boiler feedwater quality. A compact skid-mounted layout simplifies installation and maximises spatial requirements for maintenance.


Seamless Integration and Commissioning
FILTEC delivered full mechanical, electrical and automation installation on site and integrated the system with Fonterra’s SCADA network via a remote I/O panel. The design minimises manual intervention by automating start-up, shutdown and performing self-flushes for membrane protection.
RO membranes and EDI modules require infrequent cleaning with the feedwater quality used, reducing operator workload, downtime, chemical consumption. All commissioning and training were completed within the scheduled shutdown window, enabling Fonterra to bring the new boiler online without delays.
CIP Servicing and Performance Support
Post-commissioning, FILTEC’s local Dunedin service team has provided CIP services. Performance data is monitored by site Operators to ensure the RO and EDI units continue to meet design treated water quality parameters and flows.

Consistent High-Purity Water and Operational Efficiency
The new RO–EDI system delivers reliable high-purity water that protects boiler equipment and maintains steady steam output for production. Water quality has exceeded design targets, supporting consistent boiler operation and reduced maintenance needs. By producing consistent, low-conductivity feedwater, Fonterra has enhanced operational stability and helped advance its long-term sustainability goals.

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For a concise, printable overview of the Fonterra Edendale RO-EDI Boiler Feedwater Plant, download the project profile below.