Switchgear cabins installed as Clarks Beach Wastewater Treatment Plant prepares for commissioning

The final pieces of electrical infrastructure have been installed at the $38.3 million upgraded Clarks Beach Wastewater Treatment Plant, ahead of cold commissioning works Watercare is scheduled to begin early next year.

This milestone marks a crucial step forward in delivering essential wastewater infrastructure to support projected growth in Auckland’s south-west, which is expected to reach approximately 30,000 people by 2050.

Watercare project manager Dave Kennerley says it took about a day to lift and install the two switchgear cabins.

Both switchgear cabins were lifted into place by crane at the Clarks Beach Wastewater Treatment Plant.

“Together, these cabins will serve as the plant’s engine room, powering critical systems that treat and manage wastewater for the growing Clarks Beach community.

“Each cabin is a self-contained unit, fitted with reinforced flooring to support the switchboards, internal lighting, and poly panelling for complete soundproofing.

“The two switchgear cabins are fully containerised units prepared by McKay Hamilton who are the lead electrical sub-contractor on the project.

“A six-week fit-out included painting, pedestrian door installation, internal lining, flooring, and pre-mounted cable containment to streamline on-site works.

“Once complete, the switchboards and programme logic control cabinets were integrated into each cabin before transporting them to site for final positioning and cable installation.”

Kennerley says the upgraded plant is on track to be completed by June 2026.

“Once it’s brought into service, the Clarks Beach Wastewater Treatment Plant will be capable of treating over five million litres of wastewater per day to a very high standard, thanks to the advanced MABR and MBR technologies now being installed.

“These technologies are highly effective at removing organic matter and nutrients, largely thanks to microorganisms - or bugs - that do the heavy lifting. We simply create the right conditions for them.

“The membranes are very effective at removing pathogens, and any that pass through are further treated using ultraviolet disinfection, ensuring the final discharge meets stringent environmental standards.”

Kennerley adds that work is now complete on the Clarks Beach outfall, which will transport highly treated wastewater and discharge it approximately 100 metres into the Waiuku Channel - a highly dynamic part of the harbour where it will quickly disperse.

“In the new year, our crew will kick off cold commissioning - the first stage in bringing the upgraded wastewater treatment plant into service.

“During this phase, we’ll carry out a series of checks and preparation works to ensure the plant is mechanically and electrically sound and fully operational before the treatment process begins.

“The goal of cold commissioning is to minimise risks and identify potential problems with individual items of plant in a safe environment.

“After the cold commissioning is finished, we’ll then move into the hot commissioning process, where wastewater is introduced to check the treatment processes, before connecting it into the outfall where the wastewater will be dispersed.

“We want to thank the community for their patience and support throughout the upgrade works, especially those who experienced disruptions while this critical work took place.”