The opening of NPDC’s new thermal drying facility this morning will help future-proof wastewater treatment in New Plymouth District for another 25 years.
Formally opened by managers from the National Infrastructure Funding and Financing Ltd (NIFF) and NPDC, the new facility at the New Plymouth Wastewater Treatment Plant has been in construction for the past two and half years. It replaces the previous dryer which had become difficult to safely repair and maintain due to its age and the building’s limitations.
Drying excess sludge is a key part of the process that treats wastewater from nearly 62,000 residents from Waitara to Ōakura.
The project will end up within the $75.4m budget, $37m of which came from the Government’s Infrastructure Reference Group Fund, managed by NIFF.
“It’s taken hundreds of thousands of work-hours to get to this point with contractors from Taranaki and overseas working on various parts of the project,” says NPDC General Manager Operational Excellence Sarah Downs.
“The last thermal dryer had done us great service but it just couldn’t be repaired anymore after 22 years of service, and it was critical that it be replaced.
“The new one has been designed to be more energy-efficient and it can handle larger volumes of sludge – about 20 per cent more – which gives us some future-proofing for a growing population.”
The previous thermal dryer was 20 years old when construction started in 2023 of the new thermal dryer and its building, silos, access road and other site upgrades.
At today’s opening were representatives from main contractor Downer, thermal equipment supplier Haarslev and facility designer Beca.
At a glance:
- Every year, the NPWWTP treats about 10.8 million cubic metres of wastewater – up to 4,300 Olympic-sized swimming pools’ worth.
- When it was built in 1984, the NPWWTP was the first of its kind in New Zealand.
- The plant reuses 500,000 litres of treated effluent every day as part of its operation instead of using regular drinking water.
- The treatment plant uses bacteria to ‘eat’ the wastewater as part of the treatment. This causes the number of bacteria to grow, and the system syphons off excess bacteria (sludge) to be dried in the thermal dryer.
- The dried sludge has been sold as the nutrient-rich fertiliser BioBoost.
