Queanbeyan Sewage Treatment Plant Upgrade

We are responsible for the management and operation of the Queanbeyan Sewage Treatment Plant (QSTP) that provides treatment to sewage from Queanbeyan prior to discharge into the Molonglo River approximately 9 km upstream of Lake Burley Griffin.

Queanbeyan’s existing sewage treatment plant was constructed in the 1930s with the most recent major upgrade being completed in the 1980s. The existing treatment plant has a design capacity of 34,500 equivalent population (EP) and is currently servicing up to 52,000 EP seasonally. This plant is overloaded, at the end its service life and needs replacing. Due to its age, the plant is experiencing structural failure, reduced equipment reliability and maintenance issues.

The upgrade will replace the existing sewage treatment plant with a modern, robust and reliable treatment facility that will provide additional capacity and improve treatment reliability. It will provide 75,000 EP of treatment capacity to support growth and development in Queanbeyan including currently approved development.

Delivery of the project is well advanced, with design complete and planning approvals in progress.

We are responsible for the management and operation of the sewerage system that serves Queanbeyan. This includes the:

• Queanbeyan sewerage collection network and pumping stations
• Morisset and Jerrabomberra sewerage trunk mains; and
• Queanbeyan sewage treatment plant.

The QSTP is located on the banks of the Molonglo River in Jerrabomberra ACT. Treated effluent from QSTP is discharged to the Molonglo River approximately 9 km upstream of Lake Burley Griffin.

It provides treatment to a catchment that includes urban, light commercial, light industrial and some rural residential properties, including the NSW neighbourhoods of Crestwood, Jerrabomberra, Karabar, Queanbeyan, Queanbeyan East, Queanbeyan West, and Greenleigh, and the ACT suburb of Oaks Estate.

The Queanbeyan sewerage collection network includes a gravity collection system with 15 pump stations, approximately 286 km of pipeline and two major trunk mains that convey sewage to the QSTP.

Googong Township has its own water recycling plant. Googong will continue to be served by its own sewage collection and treatment system, which is completely independent of the Queanbeyan sewage system.

The Queanbeyan sewerage collection network and location of QSTP.  QSTP also treats sewage collected from the Icon Water sewage collection network within Oaks Estate.

The existing treatment plant is overloaded, at the end its service life and needs replacing. Due to its age, the plant is experiencing structural failure, reduced equipment reliability and maintenance issues.

Current sewage inflows exceed the treatment capacity of the existing treatment plant

The existing sewage treatment plant is   operating well above its design capacity. This limits the ability of the plant to achieve the treatment levels required prior to discharge into the Molonglo River. The existing treatment plant has an assessed capacity to treat sewage from an equivalent population (EP) of 34,500. An assessment of inflow completed in 2019 estimated that the plant was receiving a median load of 43,400 EP and a seasonal peak load of 52,000 EP. The population served by the QSTP is forecast to continue to increase as new and already approved developments connect to sewer. This will increasingly overload the existing STP. An assessment of future needs estimates that the QSTP will be required to treat an equivalent population of 73,000 EP by 2045.

We operate the Queanbeyan STP under the terms of an Environmental Authorisation granted by the EPA under the Environmental Protection Act 1997. During the most recent annual reporting period (2021-22) the effluent discharged into the Molonglo River from QSTP failed to meet the water quality requirements of this authorisation on multiple occasions.

Continued operation of the existing treatment plant as Queanbeyan’s population grows presents an increasing risk that the STP continues to fail to meet the EPA regulatory Environmental Authorisation requirements for effluent discharged to the Molonglo River. The resulting pollution could result in adverse impacts on aquatic species in the Molonglo River and Lake Burley Griffin, environmental prosecution, and substantial reputational damage.

The project will replace the existing sewage treatment plant with a modern, robust and reliable treatment facility that will provide additional capacity and improve treatment reliability. The upgrade provides 75,000 EP of treatment capacity to support growth and development in Queanbeyan including currently approved development.

The upgrade provides a tertiary treatment standard including filtration and UV disinfection that will improve the quality of the treated effluent discharged into the Molonglo River upstream of Lake Burley Griffin and enable us to continue to meet our regulatory requirements. The treatment plant has been designed to be expandable by 50% to a total of 112,500 EP if required in the future.

The proposed QSTP upgrade is located above flood level on the existing site.

The QSTP will be constructed on the existing lease area, located above the nominated flood level for the site, reducing the risk of damage during flooding. The location enables the existing STP to continue to provide treatment during the construction, testing and commissioning of the new facility, which is estimated to take two years.

The new STP will be robust, reliable and sustainable, and protect public health and the environment for future generations. This will provide for both immediate service needs and the identified future needs.

The upgrade represents a solution that provides value for money, achieves targeted sustainability and public health outcomes, and will continue to meet regulatory requirements.

Additional benefits of the project include:

• Securing Queanbeyan’s sewage treatment needs for future growth
• Improved ability to control the water quality discharged to the environment and to protect public health
• Improved odour and noise outcomes
• Improved workplace health and safety for workers and visitors to the facility
• Providing improved treatment reliability
• Providing improved protection of the treatment plant against flooding and climate change sustainability
• Providing a source of recycled water that can be used for applications such as dust suppression
• Providing a local facility to receive and treat septage waste collected from domestic septic tanks and aerated wastewater treatment systems
• Improved treatment of the biosolids produced by the treatment process to a quality that is suitable for agricultural reuse
• Providing improved treatment of the waste screening and grit materials generated during the treatment process

Providing improved traffic access to the treatment plant by sealing the access road.

An extensive Community and Stakeholder Engagement Plan, based on the IAP2 protocol, has been prepared as part of the project. The aim of the Engagement Plan is to facilitate stakeholder and community input into key project decisions. In this way we hope to ensure that the new facility will properly address community concerns, minimise environmental impacts, maximise potential benefits, while remaining affordable and sustainable.

Key community engagement activities include:

• Public exhibition of the Masterplan
• Public exhibition of the Community and Stakeholder Engagement Plan
• Public exhibition of the Environmental Impact Statement
• Identification of negotiable aspects of the project and a minimum consult level of engagement with stakeholders on these aspects
• Public exhibition of the Development Application.

Download the Community and Stakeholder Engagement Plan(PDF, 2MB)

As part of the regulatory approvals process an environmental impact statement (EIS) has been prepared. The EIS describes the Proposal and provides an assessment of the potential environmental impacts that could occur as a result of its construction and operation. It also identifies measures to be implemented to avoid and minimise those impacts. The EIS was informed by environmental investigations, the concept design and stakeholder consultation. It focuses on the following environmental themes:

• Planning and land status
• Traffic and transport
• Utilities
• Materials and waste
• Asbestos
• Soils and geology
• Water quality and hydrology
• Climate change
• Air quality
• Health
• Socio-economic
• Noise
• Hazard and risk
• Bushfire
• Biodiversity
• Heritage
• Entity requirements

Mitigation measures identified in the EIS will be incorporated into the development application and design and construction documentation.

The completed EIS can be viewed on the ACT Government’s website at the following link:

https://www.planning.act.gov.au/applications-and-assessments/development-applications/browse-das/development-application-details?da-number=202342384&amendment-version=(External link)

Our sustainability commitments are outlined in two publicly available policies: Sustainable Design Policy for Council Buildings and QPRC Operations Sustainability Policy. In line with our Sustainable Design Policy for Council Buildings, the Infrastructure Sustainability Council (ISC) has been engaged to provide third party sustainability certification for the project. The goal is to obtain both Design and As-Built Infrastructure Sustainability (IS) Ratings of Excellent.

A Sustainability Management Plan (the SMP) has been prepared to outline how sustainability initiatives will be integrated into the project through a sustainability management system that allocates roles and responsibilities and tracks performance throughout the design and construction of the project.  The SMP describes how the project team proposes to manage the project to achieve ‘Excellent’ Design and As-Built IS Ratings. Project specific sustainability targets include:

• 15% reduction in green-house gas emissions compared to the base case through modelling (design) and monitoring (construction)
• 10% reduction in total water use compared to the base case
• Opportunities to reuse spoil are identified and implemented, targeting a >80% (by volume) of spoil to be reused
• Minimise total waste to landfill through waste avoidance initiatives and prioritisation of reuse and recycling, targeting >40% by volume of office waste to be recycled
• 20% substitution of non-renewable energy using renewable energy
• 50% substitution of potable water use using non-potable water
• Embedding consideration of environmental, social and economic factors when selecting suppliers/services using multi-criteria analysis
• “Excellent” IS Design and As-Built Rating.

Download the Sustainability Management Plan(PDF, 2MB)

Current contracts awarded for the project by tender are listed below:

• Contract 10/2015 for Sustainability Rating Support Services to AECOM Australia Pty Ltd
• Contract 12/2015 for Design Consulting Services to Hunter H2O Pty Ltd
• Contract 2020-54 for Supply & Delivery of Screening & Screening Washing Equipment to Hydroflux Epco Pty Ltd
• Contract 2020-55 for Supply & Delivery of Grit Removal Equipment to VOR Environmental Australia Pty Ltd
• Contract 2020-56 for Supply & Delivery of Bioreactor & Digester Aeration, Mixer Systems and Air Scour Blowers Equipment to Xylem Water Solution Australia Ltd
• Contract 2020-57 for Supply & Delivery of UV Disinfection Equipment to Xylem Water Solution Australia Ltd
• Contract 2020-60 for Supply & Delivery of Centrifuge Equipment to GEA Westfalia Separator Pty Ltd
• Contract 2020-61 for Supply & Delivery of WAS Thickener Equipment to Hydroflux Epco Pty Ltd
• Contract 2020-62 for Supply & Delivery of Clarifier Equipment to Hydroflux Epco Pty Ltd.
• Contract 2021-14 for Supply & Delivery of Scum Harvester Equipment to VOR Environmental Australia Pty Ltd
• Contract 2021-15 for Supply & Delivery of Chemical Dosing Skid Equipment to Trility Solutions Australia Pty Ltd

A regulatory roadmap was prepared as part of the Master Plan that outlines the regulatory and planning approvals process for the project.

The Sewage Treatment Plant (STP) is located within the ACT and will require:

• Planning approval from ACT Environment, Planning and Sustainable Development Directorate (EPSDD) under Schedule 4 of the ACT Planning and Development Act 2007
• Environmental authorisation from the ACT Environment Protection Authority (EPA) under the Protection of the Environment Operations Act 1997; and
• Operating certificates for Design & Construction and Provision of Service from the ACT Utilities Technical Regulator under the Utilities (Technical Regulation) Act 2014.

The ACT Government approvals process considers the Federal Environmental Protection and Biodiversity Conservation Act 1999.

Additionally, the project requires regulatory approval from the NSW Government Department of Planning and Environment (DPE) under Section 60 of the Local Government Act 1993.

Download the Regulatory Road Map(PDF, 138KB)

Preliminary cost estimates for the project have been developed from a risk-based engineering cost estimate during the design phase. The current cost estimate for the total outturn project cost including work to date, contingency and escalation allowance is $188M.

The project will be funded through contributions from QPRC’s Sewer Fund, Section 64 developer charges, loan funding and government grants.

QPRC has received a $3M grant from the NSW Government through the Safe and Secure Water Program (SSWP) for development of the business case, reference design and to obtaining planning approval.

Anticipated dates for key project milestones are as follows:

• Revised business case approved – June 2024
• Planning approval (EIS and Development Application) – August 2025
• Detailed design completion – mid 2025
• Construction Tender Award – early 2026
• Operation of the new STP – mid 2028
• Overall project completion – early 2029

A procurement plan for the project was prepared early in the project and has been reviewed as the project progresses. The plan considers alternative delivery systems suitable for the characteristics and risks of delivering this project.

Key features of the procurement strategy are:

• The project will predominantly be delivered using a design then construct delivery approach
• The project is being managed by our Contracts and Projects team with support from external consultants
• A design will be prepared by a design consultant to document the project technical requirements and facilitate review by regulatory stakeholders
• Planning approvals will be obtained by Council during the design phase
• Construction will be delivered by a Principal Contractor. Engagement of the Principal Contractor will be by open Expressions of Interest with an Early Tenderer Involvement period for the shortlisted tenderers
• We will undertake early engagement with key equipment suppliers and award contracts for supply of equipment without installation. Equipment supply contracts will be novated to the Principal Contractor with equipment to be installed by the Principal Contractor
• Contract administration and technical support during construction will be provided by external consultants

We are finalising the detailed design and tender documentation for the upgrade and will call for expressions of interest for construction of the work as soon as planning approvals are confirmed.

To minimise procurement delay risks early vendor engagement has been used to select and establish contracts for the supply and delivery of key equipment packages for the upgrade.

A final Environmental Impact Statement for the project was approved by the ACT Government in June 2023. We lodged a Development Application with the ACT Government in December 2023 which has been delayed due to archaeological test excavations to achieve ACT Heritage approval.   We expect the DA to be approved in August 2025.

The project team are continuing to progress work to assist the project becoming ready for construction. Key actions include:

• Obtaining development approval from the ACT Government
• Progressing discussion with the ACT EPA regarding the operating and licencing requirements for the new facility
• Undertaking further early vendor engagement and tendering for equipment supply for the works
• Finalising detailed design and tender documentation
• Progressing design and  approvals for items including power supply upgrade and potable water supply.

What’s next?

• Further archaeological investigation
• Responding to DA request for information
• Seeking Expressions of Interest from suitably qualified contractors
• Submission to achieve an Infrastructure Sustainability Council (ISC) Design Rating
• Submission of a development application for the Mountain Road upgrade, boundary adjustments and electrical network adjustments

An design presentation and virtual tour was held on 4 April. This was recorded and is now available to view.