NSW farmers to benefit from $94m wastewater facility upgrade

Two digesters have been installed at the North Head Water Resource Recovery Facility (WRRF), marking an important milestone in the facility’s $94 million upgrade.

The digestors will increase the amount of biosolids that can be reused as agricultural fertiliser from 40 to 70 tonnes per day by 2043. This fertiliser will continue to be delivered to farms in the Central Tablelands of New South Wales, including Bathurst and Orange.

The North Head WRRF provides wastewater facilities for one million Sydneysiders, from Seven Hills to Yagoona, to Ku-Ring-Gai and Collaroy. Sydney Water began to upgrade the facility in 2021, to improve how biosolids are processed for use as fertiliser for agricultural purposes.

The upgrades provide circular economy benefits in that almost 100% of biosolids will be reused for agricultural purposes. Recovering these biosolids also helps reduce waste to landfill while reducing the number of chemical fertilisers used on farms and enhancing soil structures.

Kelvin Chow, Sydney Water North Head Project Interface Manager, said the upgrades are a step forward in wastewater treatment.

Almost 60% of the facility’s total energy needs come from renewable sources, with Sydney Water constantly looking for alternative and renewable energy sources.

The facility features a hydroelectric generator, driven by treated wastewater which falls down a long drop shaft on its way to the deep-water ocean outfall, generating kinetic energy.

The facility also uses cogeneration to meet some of its energy needs. The anaerobic digesters capture methane gas, which is used to power a combustion engine that drives an electricity generator.

Upgrades to the North Head WRRF are due for completion by late 2024.