Securing the future of water for Queanbeyan

The Queanbeyan STP Upgrade will replace Queanbeyan’s existing sewage treatment plant with a modern treatment facility that protects public health and the environment for future generations.

The new 75,000 EP Queanbeyan Sewage Treatment Plant (STP) provides for the continued growth and development of Queanbeyan and is designed to meet stringent environmental objectives for effluent discharge into the Molonglo River that flows into Canberra’s Lake Burley Griffin. The design of the new facility has been developed in close consultation with Queanbeyan-Palerang Regional Council (QPRC) with a strong focus on reliable operation, sustainability and whole of life value to Council.

The Queanbeyan STP Upgrade uses an advanced treatment process that includes a continuous flow oxidation ditch and clarifiers providing biological nutrient removal, tertiary filtration and UV disinfection. The plant is configured with the ability to operate in a solids-contact mode to provide enhanced treatment during wet weather flows.

As the design consultant, Beca HunterH2O is supporting QPRC in delivery of the project through a scope of work that includes:

• Site investigations for the design and EIS
• Concept design and business case
• Coordination of the preparation of an Environmental Impact Statement
• Detailed design and tender documentation
• Tendering and procurement support
• Construction and commissioning support.

Extensive geotechnical investigation was undertaken in connection with the proposed upgrade of Queanbeyan STP. Beca HunterH2O was responsible for briefing, engaging and managing our sub-consultant, Douglas Partners, in addition to reviewing their outputs and commissioning further works (which are ongoing). The works completed by Douglas Partners included:

Site investigations

• 40 boreholes drilled by three rigs across a period of three weeks
  • In-situ testing
  • Geo-environmental sampling
  • Installation of two groundwater monitoring wells
  • Management of bushfire and poor air quality risks.
  • Laboratory testing

• Geotechnical analysis and design, accommodating project-specific considerations tailored to components of the design detailed by Beca HunterH2O, including:
  • Large bulk excavations
  • New pavements
  • Complex footing systems beneath settlement-sensitive structures.
  • Provision of a factual geotechnical report and interpretive geotechnical report.
• Finite element analysis of settlements to inform foundation design for key water retaining structures.

Beca HunterH2O’s geotechnical liaison officer was present onsite to manage the consultant due to the large scale of the works and the HSEQ issues that arose as a result of the 2019/20 bushfires.

Durability Plan

Beca HunterH2O prepared a durability plan for the Queanbeyan STP Upgrade Project. The objective of the Durability Plan is to provide an overarching framework to inform the design basis, design, construction, operations and maintenance phases for the components of the Queanbeyan STP Upgrade project with respect to specified end client design life requirements.

The Durability Plan is a live document and is intended to provide the minimum requirements for durability design and material selection. Where a selected or supplied material is of a higher grade or quality than the material specified in this report, the selected or supplied material will take precedence. This design and documents are currently being prepared.

One of the key challenges of the project was assisting QPRC on achieving regulatory approvals given the sensitive nature of receiving waters. An innovative procurement approach has been used on this project to reduce both project risk and cost.

Looking forward to completion 

The project is currently in concept design. Following a detailed concept design Beca HunterH2O is working with QPRC to take equipment packages to the market (e.g. blowers, screens, UV systems, dewatering). This enables the team to optimise lifecycle costs and to involve operators in equipment decision making. The next stage of design will progress with a high degree of certainty and we are confident a de-risked design will be presented to market securing enhanced value for QPRC.

Another exciting component of this project is development of the next generation operating system on the back of our digital design processes.

All project deliverables and plant commissioning are expected by January 2024.

Hear about how we're securing the future of water for Queanbeyan in the video below!