Upgrading Murwillumbah's Wastewater Treatment Plant

Council is planning to upgrade the Murwillumbah Wastewater Treatment Plant (WWTP) to cater for further residential, commercial and industrial growth in Murwillumbah. The upgrade will also ensure the treatment plant continues to meet its NSW Environment Protection Authority (EPA) licence conditions.

The current treatment plant

Currently, the Murwillumbah WWTP:

• has a capacity of 16,000 ep (equivalent persons)—the amount of wastewater produced on average by 16,000 people
• processes up to 3 megalitres of wastewater daily, with a significant portion further treated for reuse and supplied to the Tweed Jockey Club and Co-Generation Plant at Condong
• safely discharges the remaining treated wastewater into the Rous River—under strict licence conditions set by the EPA.

Why the upgrade is needed

Murwillumbah is growing, and with that comes the need for modern, future-ready infrastructure. This upgrade will ensure the treatment plant:

• can support further residential, commercial and industrial growth in Murwillumbah
• continues to meet NSW Environment Protection Authority (EPA) licence conditions
• can manage peak loadings, such as during holiday periods
• supports the environmental health of the fragile Rous River system.

About the upgrade

The Murwillumbah WWTP upgrade will:

• increase the plant’s capacity to 24,000 ep, with provisions for future growth up to 32,000 ep if needed
• add an additional bioreactor to support increased capacity
• upgrade key infrastructure, including the tertiary treatment facility (which treats recycled water for reuse) and improve biosolids handling processes
• identify and implement an alternative discharge location for treated wastewater that is not reused.

The Rous River’s smaller flow and agricultural activity along its catchment make it vulnerable to environmental stress. To improve the health and water quality of the Rous River, Council is proposing to relocate the Murwillumbah WWTP's discharge point to the Tweed River, somewhere between Mayal Creek and the Condong Sugar Mill. The Tweed River is a much larger river system with stronger flow, which would allow for significantly faster dilution and dispersion.

The exact discharge location is yet to be determined and will be informed by community consultation.

The upgrade works are expected to begin in the first half of 2028, with project completion targeted for June 2030.

Concept design

Council has engaged BECA Hunter H2O to develop the preferred upgrade option into a concept design, expected to be completed late 2025. This will:

• outline the technical details of the treatment plant's upgrade
• assess any environmental impacts of the proposed works and the treatment plant’s ongoing operation
• guide how the upgrade works will be procured.

Initial studies

To guide this project and ensure the treatment plant upgrade meets the community's needs as well as EPA licence conditions, we engaged consultants to complete the following key studies:

• Water quality modelling of the mid to lower Tweed River
  • Conducted by the NSW Office of Environment and Heritage in conjunction with the University of Western Australia, this modelling assessed the environmental impact of discharging treated wastewater. It helped determine:
    • the level of treatment needed to support river health
    • the most suitable locations for future treated wastewater discharge.
• Options study
  • Led by NSW Public Works Advisory, this study explored best practices in wastewater treatment and identified the preferred option for upgrading the treatment plant.

Further environmental assessments will be undertaken before the upgrade begins. This will likely involve a Review of Environmental Factors (REF), which examines potential impacts such as noise, odour and effects on vegetation. If significant environmental impacts are identified in the REF, a more detailed Environmental Impact Statement (EIS) will be required.