Originally awarded to Earth Tech in 2005, McKay’s involvement in the project began in 2009, delivering the electrical, control, and instrumentation portion of the work for the main treatment plant and 13 associated sewerage pump stations. Over the course of the project, the principal contractor changed through several organisations including WI Group, Pentair, and Trility. The plant now operates as part of Kaipara District Council’s three waters infrastructure under Ventia’s management.
McKay was involved from the early stages of the project, contributing to the electrical and control concept design, including the development of the control philosophy and switchboard design. This was followed by the detailed design, installation, testing, and commissioning of the complete electrical, control, and instrumentation systems. The scope included the delivery of custom-designed switchboards, programmable logic controller (PLC) systems, supervisory control and data acquisition (SCADA) and historian platforms, telemetry systems, instrumentation, and motor control infrastructure.
The control system architecture was designed to maximise operational efficiency and reliability while reducing installation complexity. For the main treatment plant, McKay implemented a smart, communication-based control structure that significantly reduced field wiring requirements. The pump station switchboards were specifically engineered for the project, with a strong emphasis on durability, operational accessibility, and ease of maintenance in all weather conditions.
The completed system incorporated Prisma and Cubic switchboards, Schneider Premium PLCs with Advantys I/O for the main plant, Kingfisher CP11 remote terminal units (RTUs) for outstations, Citect SCADA and Historian platforms, DNP3 telemetry communications, Schneider switchgear and speed drives, and Endress+Hauser instrumentation. The integration of these systems provided a robust and highly functional control environment capable of supporting the long-term operation of the wastewater treatment network.
Following completion, McKay continued its involvement with the facility as the control systems maintenance contractor, supporting ongoing optimisation, reliability, and asset performance. This long-term relationship reflects McKay’s capability to deliver complex water and wastewater infrastructure projects and provide ongoing technical support for critical community assets.
Delivered on time and within budget, the Mangawhai Wastewater Treatment Plant project demonstrates McKay’s expertise in electrical engineering, industrial automation, and infrastructure delivery, as well as its ability to work collaboratively across evolving project teams and with operational stakeholders to achieve successful project outcomes.
