MOA POINT WASTEWATER TREATMENT PLANT

The Project

McKay was engaged by Wellington Water to deliver the Electrical, Instrumentation, and Controls (EIC) Renewals programme at the Moa Point Wastewater Treatment Plant, a complex, multi-package project focused on modernising and replacing ageing electrical and control systems critical to the plant’s ongoing performance.

One of the key challenges of this programme is that the facility must remain fully operational throughout the works, requiring meticulous planning, staged delivery, and continuous coordination with plant operations at every step. Once complete, the project will deliver improved reliability, modernised process control, and enhanced operational efficiency in support of Wellington Water’s long-term asset management strategy.

Project Deliverables

McKay’s scope covers the full renewal of electrical, instrumentation, and control systems across the Moa Point WWTP.

• LV Switchboards, Distribution Boards & MCCs: Replacement of low voltage switchboards, distribution boards, and motor control centres across the plant, designed to increase system reliability and provide capacity for future load growth.
• Cabling Infrastructure: Installation of new cable containment systems and cabling to support power and control upgrades, including rerouting and labelling of existing circuits to ensure full traceability and safe maintenance access.
• PLC & SCADA Upgrades: Upgrade of PLC and SCADA interfaces to improve reliability, redundancy, and system monitoring, with cybersecurity considerations incorporated to safeguard critical infrastructure against emerging threats.
• Operational Integration: Careful tie-ins with existing operational systems to maintain continued treatment capacity during cutovers, supported by comprehensive testing and temporary bypass strategies to prevent any process interruptions.
• Compliance & Quality: All works designed and delivered in accordance with NZS/AS standards, seismic safety requirements, and Wellington Water’s operational protocols, with additional quality checks embedded into each stage to ensure all assets meet regulatory and client performance expectations.

Our Approach

The defining challenge of Moa Point is that there is no opportunity to simply shut the plant down, wastewater treatment must continue uninterrupted throughout the entire programme. This shapes everything about how McKay has approached delivery: works are carefully staged, cutovers are planned in close consultation with plant operations, and temporary bypass strategies are in place to ensure no stage of the upgrade compromises the facility’s treatment capacity.

The breadth of the scope, spanning electrical, cabling, control systems, and compliance,  requires a fully integrated team capable of managing multiple workstreams simultaneously without losing coordination. McKay’s experience across similar live-environment renewals at water and wastewater facilities has been central to navigating the complexity of this programme safely and effectively.