A $94 million upgrade to the North Head Water Resource Recovery Facility (WRRF) has seen more than 100 workers construct and install the two new digesters, which will almost double the facility’s capacity of sludge production for fertiliser from 40t to 70t per day by the year 2043.
Recovering biosolids from the new digesters will help reduce the waste in landfill while also reducing the number of chemical fertilisers that are used on farms and enhance soil structures, helping to boost the agricultural sector in New South Wales.
The North Head WRRF provides wastewater facilities for one-million Sydneysiders; from Seven Hills in the west, to Yagoona in the south and Ku-Ring-Gai and Collaroy in the north.
In 2021, Sydney Water began important upgrades to the facility to improve how it processes biosolids for use as fertiliser for agricultural purposes.
Sydney Water North Head Project Interface Manager, Kevin Chow, said the upgrades to the facility are important steps to move forward in figuring out how to treat wastewater.
“We proudly produce biosolids for agricultural purposes, which help reduce our environmental footprint,” Mr Chow said.
“Not only will these upgrades result in increased biosolids production, which are stable and odour free, but they will ensure the ongoing reliability of the facility.”
The North Head WRRF sources almost 60 per cent of the facility’s total energy needs from renewable sources, with the newly upgraded facility to include a hydroelectric generator.
The generator will allow for wastewater to fall down a long drop shaft on its way to the deep-water ocean outfall, to which the falling water will have enough kinetic energy to drive a water-powered generator.
Methane Gas (biogas) is also captured from the anaerobic digesters and used to power a combustion engine that is used throughout the facility to drive an electric generator as part of North Head’s co-generational approach to meet some of its energy needs.
The upgrades to the facility are expected to be completed by late 2024.
Featured image: Sydney Water Principal Project Manager, Ian Blair (left), and Project Interface Manager, Kevin Chow. Image credit: Sydney Water.