The newly-completed Mangere Pump Station

Māngere Pump Station is the largest wastewater system in Auckland and will massively reduce wastewater overflows, improving the quality of Auckland’s waterways and beaches

Heatwave Mechanical has been working on this project for the past few years, with the project about to be completed and handed over to Watercare.

“We just love playing our part and bringing our expertise to major infrastructure projects like this,” says Heatwave’s Maksim Manko.

Case study Q&A

When did this project commence?

Maksim: I originally priced this job in 2018. From here I re-priced it several times while the specification and commercial terms developed. We secured the Contract in late 2021, and the client indicated that the job would take place in 2023/2024. However, due to the volatility of material and labour pricing during the Covid years, they wanted to implement an early design and procurement strategy to secure all materials well in advance of the installation and commissioning. So, in early 2022 we finished design and implemented early procurement.

What has this project entailed?

Maksim: The Central Interceptor project is a major utilities infrastructure project that will massively upgrade Auckland’s sewer capacity for the next 100+ years. The final part of the sewer is Māngere Pump Station – at the bottom of the drywell are the large hydraulic pumps. Heatwave’s scope of work has been to provide industrial-scale ventilation systems to the drywell, and ventilation/cooling systems to the switchboard rooms and generator room.

The switchboard rooms have critical electrical equipment for the 24/7 functioning of the Central Interceptor and require a positive room pressure, highly filtered air and close-control balance with the supply/ return-air from these rooms. The ventilation system is armed with control dampers that either recycle or exhaust the air, dependant on temperature control requirements, in order to keep the switchboard rooms as stable as possible, ensuring positive pressurisation. The ventilation systems are corrosion resistant – built to last.

What have been the major milestones?

Maksim: The Māngere Pump Station project is just about to be handed over to the client, Watercare, by the end of 2024. We are working on other minor plantroom projects along the Central Interceptor which are also to be handed over by the end of 2024.

I have to say that one of our milestones, which I also personally enjoyed, was the completion of the drywell ventilation shaft which is nearly 40 metres in length and a very impressive installation from our team. Having priced this job back in 2018, I really enjoyed seeing this being built, and now with the project being handed over I am very proud of our team’s hard work, dedication and extensive experience in tunnelling projects which has put our best foot forward throughout this entire project.

What challenges have been faced along the way, and what solutions was Heatwave Mechanical able to provide?

Maksim: The design of the switchrooms was a very technical process which I felt that Heatwave contributed significant engineering decisions to reach a fantastic solution. The solution involves a clear Functional Description, so the supply/return-air fans modulate with the various control dampers in order to achieve the correct room pressure and temperature by either recycling air, or exhausting warm air.

The construction of the 40-metre drywell shaft and various ventilation droppers was also a great feat that was challenging, but well within our reach as our skilled tradesmen and managers have faced similar construction challenges on other major tunnelling projects such as Waterview Tunnel and the City Rail Link.

What is the next stage for this project?

Maksim: As we look to handover the ventilation systems to the client in late 2024, we are focused on long-term asset maintenance and management to ensure the durable ventilation systems serve the Central Interceptor system well, without failure, for many years to come.

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