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Bolivar Wastewater Treatment Plant

Preparing for a growing South Australia

Location

  • Australia

Client

  • SA Water

Project Status

  • Complete

Banner image courtesy of SA Water

At a glance:

  • The largest wastewater plant of its kind in South Australia, that serves over one million residents
  • Delivered with advanced modelling and automation to help deliver uninterrupted operations
  • Designed for long-term resilience, environmental performance and population growth
  • A benchmark project transforming legacy infrastructure into a future-proofed public asset

In the suburb of Bolivar, just north of Adelaide’s city centre, lies an unassuming powerhouse of climate-resilient infrastructure and public health.

Hidden in plain sight, the Bolivar Wastewater Treatment Plant – South Australia’s largest – has been treating wastewater since the 1960s. Nowadays, it processes over 70% of Adelaide’s sewage.

In a region that’s no stranger to drought, Bolivar is also a vital source of recycled water. More than 30% of sewage that passes through Adelaide’s three wastewater treatment plants is recycled for use in parklands, community grounds, and agriculture. There is also strong demand for biosolids from Bolivar, which farmers have been using for soil and crop enrichment for decades.


Transforming legacy water infrastructure into a modern environmental asset

The plant’s original inlet required upgrading to support burgeoning population growth across Adelaide, which is driving a need to treat higher inflows in the future as new developments progressively connect to SA Water’s network. WSP and Fulton Hogan were engaged by SA Water to support the significant upgrade – one of the largest in the plant’s history.

Appointed as the lead engineering consultant, our project team worked closely with Fulton Hogan and SA Water to deliver this critical project.

At Bolivar, we’ve brought 1960s infrastructure into the modern-day to prove that, with the right engineering vision, even legacy infrastructure can rise to meet the demands of a new century.

Increasing capacity whilst remaining operational

Upgrades to water assets require careful planning. Interrupting service or supply is rarely an option, as was the case with this upgrade, with the plant required to remain operational throughout the works.

Undertaking works in an operational plant also presented other challenges with installation of the new inlet structure needing to avoid existing underground services, including high voltage transformers, along with other site constraints.

Engineering solutions developed by the project team not only delivered, but set new benchmarks in design integration, digital engineering, and constructability.

The development and use of a highly detailed 3D engineering model was key. This model provided a design tool and enabled the design, construction and operations teams to collaborate in real-time. Used throughout planning and construction and to engage with subcontractors, the digital-first approach significantly improved efficiencies and project outcomes.

Incorporating modular design elements, such as the switchroom, which was prefabricated off-site and delivered as a complete module, also streamlined construction and reduced site risks.

The team’s cutover strategy included commissioning of the new inlet structure while the old system continued operating. The flow was gradually redirected to the new system with full operational readiness in place before the old inlet was decommissioned.

The team’s careful planning and innovative engineering solutions resulted in minimal to no disruption to wastewater treatment at the Bolivar plant, supporting continuity of services for SA Water’s customers.


Placing sustainability and community at the forefront

Sustaining healthy communities and safeguarding the health of our local waterways and ecosystems is paramount. Environmental sustainability was a core considerationthroughout the upgrade, with the need to reduce the risk of untreated wastewater discharges, particularly during peak flow events, critical.

Key sustainability outcomes included increasing capacity for the future population without compromising environmental performance, improved containment and flow, and optimised hydraulic design to improve operational efficiencies.

Reuse of existing infrastructure where feasible extended asset life and reduced the need for new construction and the associated environmental impacts.

Modern methods of construction, such as the off-site fabrication of the switchroom, reduced on-site waste, minimised disruption and improved quality control.


Supporting Adelaide’s economic growth and water resilience

More than one million residents across metropolitan Adelaide depend on Bolivar for the safe and reliable treatment of their wastewater. The plant’s processing capacity has been doubled from 300 million litres every day to approximately 630 million litres – all without compromising environmental standards.

Operational risks and maintenance costs have been reduced, whilst usability and performance have improved, providing long-term value to the community.

By introducing smarter, more adaptive solutions, the new and significantly larger inlet not only provides for residents, but caters for future population growth as new greenfield developments connect to SA Water’s sewer network.

Setting a new benchmark for wastewater infrastructure

With utilities currently facing challenges around upgrading ageing water infrastructure while preparing systems for growth, this project at Bolivar provides a blueprint for the industry. The team successfully delivered the upgrade whilst maintaining a fully operational wastewater treatment plant.

The solution encompassed technical innovation, collaborative delivery and a commitment to quality, and has resulted in a project that prepares critical infrastructure for a growing state.

Final works on the upgrade to the Bolivar Wastewater Treatment Plant are scheduled for completion in March 2026.

 

Frequently Asked Questions - Bolivar Wastewater Treatment Plant

What makes the Bolivar Wastewater Treatment Plant upgrade so significant for South Australia?

The Bolivar upgrade is one of the largest of its kind in the state, serving more than one million residents across metropolitan Adelaide. It transforms legacy 1960s infrastructure into a modern, climate-resilient facility that can process up to 630 million litres of wastewater daily. The project strengthens South Australia’s long-term water security and supports population growth without compromising environmental performance.

How was the plant upgraded while keeping it fully operational?

Keeping the plant running throughout construction was a key requirement. The project team used advanced digital engineering and 3D modelling to plan and coordinate the works, avoiding interference with existing underground assets. A detailed cutover strategy allowed the new inlet structure to be commissioned while the old system was still in operation, ensuring uninterrupted wastewater treatment for SA Water’s customers.

What sustainability and community benefits has the upgrade delivered?

Environmental sustainability was at the heart of the project. The new design increases capacity while reducing the risk of untreated discharges, particularly during heavy rainfall. Modular, off-site construction minimised waste and site disruption, while reusing existing infrastructure reduced material use and embodied carbon. The plant also continues to provide recycled water and biosolids that support local agriculture and green spaces across Adelaide.

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