Wollongong 2500

Our Wollongong WRRF is located at the northern end of the Port Kembla industrial area with the Port Kembla Coal Terminal to the south, Wollongong Golf Course to the north and east, and Touchdown Helicopters heli-port to the west.

It is our largest facility in the Illawarra region and services a population of about 200,000 from Bellambi, Cringila, Dapto, Keiraville, Port Kembla, Unanderra, Windang, Wollongong and Wombarra.

The facility, which treats 53 ML/d, was constructed in 1958 as a primary treatment plant and has undergone several improvements and augmentations since. A 20 ML/d recycled water plant has supplied high quality industrial reuse water to BlueScope Steel since 2006. A new ocean outfall, one kilometre offshore, was commissioned in 2006. The Stage 2 Recycled Water Scheme, commissioned in 2009, provides up to 2.2 ML/d of tertiary treated and disinfected water to the adjacent golf course and the coal terminal. This includes a small volume provided to Wollongong Council for irrigation purposes. The remaining treated disinfected wastewater is discharged to the South Pacific Ocean via the deep water outfall with diffuser zone.

The facility has hydraulic and biological capacity to serve the projected 2036 population of 281,000.

We'll be upgrading various processes and upgrading different equipment at the Wollongong WRRF. This includes:

• renewing the biosolids storage area - during the treatment process we separate water and solids before treating and releasing the water to the ocean. The solids go through a further biological treatment to reduce pathogens, odours and particles that attract insects and vermin. The resulting biosolids are used in agriculture, forestry, and land rehabilitation. 100% of our biosolids are beneficially re-used, with at least 70% used in agriculture
• renewing the dewatering system - this will increase the capacity of the waste activated sludge thickening and dewatering process that generates biosolids and will introduce a new process with digester recuperative thickening which increases solids in the wastewater so they can be easily extracted
• renewing inlet works at the odour control unit (OCU) - this will include structural remediation of the inlet works area including a new OCU comprising of bio trickling filters and future provisioning for the ability to retrofit additional stages or carbon polishing if an additional level of treatment is required
• renewing the step screen - improving the technology used to screen and remove rag and other debris from wastewater coming into the facility
• upgrading the surface aerators - surface aerators push water from under the water's surface up into the air, then the droplets fall back into the water, mixing in oxygen. The jets of water break the surface with varying degrees of force to allow for aerobic biodegradation of the organic materials in the wastewater. These will be removed and replaced with diffused air. This has the benefit of using less power, provides a better oxygen saturation for the biological stream, and limits any aerosols which can be present during surface agitation
• upgrading the scum system - wastewater settles in long tanks called primary sedimentation tanks and heavy organic material sinks to the bottom (as sludge). Light material (fats, oils and greases) floats to the top (as scum) which is removed by skimmers
• replacing the recycled water membranes - membrane filtration is a process used to remove micro organisms or particles from suspension in the recycled water after the treatment process, so that it meets the Department of Health regulations so we can supply recycled water for industrial and irrigation use in the area
• replacing eight weirs within the Biological Nutrient Removal (BNR) tanks
• renewing the Primary Sediment Tank (PST) and replacing the Constant Mass Flow (CMF) valve actuator
• upgrading lighting and flooring in existing switchrooms.

Some of the minor work above started in late 2022 as part of ongoing maintenance at the facility. Construction of the larger projects started in May 2023 and will be ongoing until mid to late 2027, pending weather conditions.