Tomaree Sandbeds
Desalination makes high-quality drinking water from seawater. As one of the few water source options not dependent on rainfall, desalination was identified in the 2022 Lower Hunter Water Security Plan as a key action to help us continue to support our customers and communities with a safe and reliable water source regardless of changes in weather or climate.
This permanent seawater desalination plant will provide important water infrastructure to the Lower Hunter. Desalinated water is a particularly valuable water source as it's a reliable source of drinking water, even in a severe drought. It will significantly enhance the region's drought preparedness and response capabilities.
What is the Belmont Desalination Plant?
The Belmont Desalination Plant is Hunter Water’s approved permanent desalination plant and will be the first water source of this kind for the Lower Hunter region.
Belmont was selected as the best site for several reasons including proximity to the ocean, the ability to connect to our existing water supply network, and its relatively remote location which ensures minimal disruption and impact on the community.
The infrastructure to support the plant includes a new ocean intake, a new water treatment plant, two new water mains, and upgrading existing reservoirs to integrate desalinated water into our network.
When completed, the desalination plant will:
- Have the capability to provide up to 30 million litres (30 megalitres) of rainfall-independent drinking water per day, which equates to around 15 percent of the region's average daily demand - or around 12 Olympic swimming pools.
- Be flexible and responsive, allowing us to increase or decrease the amount of water produced as required.
How desalinated water is produced
Desalination is the process of removing dissolved salts and other particles from seawater (saltwater) to make high-quality drinking water.
1. Saltwater intake
Saltwater goes through an initial screening grill in the ocean then enters an intake pipeline through a low-velocity intake structure located above the sea floor about one kilometre offshore. The seawater flows along the intake pipeline to the seawater intake well located at the plant site at Belmont.
2. Pre-treatment
The water moves through inlet screening (via band screens) which removes larger items, then is pumped from the seawater intake well to the pre-treatment plant where coarse filters are used to remove larger particles. The seawater is then filtered through ultra-fine membranes to remove smaller particles.
3. Reverse osmosis
The cleaner seawater is then forced at high pressure through thousands of reverse osmosis membranes, which act as very fine filters, to remove dissolved salts and other particles. Fresh water is extracted, and saltwater concentrate (brine) is left behind. Around half of the seawater becomes drinking water.
4. Final treatment
The fresh water is treated to meet Australian Drinking Water Guidelines and fluoride is added to protect teeth.
5. Joins the network
The drinking water then travels through two dedicated pipelines to join the Hunter Water supply network in two locations.
6. Saltwater concentrate
The remaining saltwater concentrate (brine) is about twice as salty and about one degree warmer than the ocean. It will be combined with the other plant waste streams and pumped to the existing Belmont Wastewater Treatment Works ocean outfall, where it will be returned to the ocean, along with wastewater effluent, through a large pipe that lies beneath the seabed. The effluent and saltwater concentrate is dispersed using specially designed diffusers which return it to normal salinity and temperature quickly.
Benefits of the Desalination Plant
- Diversifies our water sources, taking pressure off our long-standing dam and groundwater sources.
- The Lower Hunter is very vulnerable to dry seasons and drought. The Belmont Desalination Plant will help to reduce the rate that our storages deplete in a long and severe drought by around six months, delaying the need to implement severe drought response measures.
- It provides a flexible, resilient and sustainable water supply source that is responsive to water supply needs.
- While rivers and dams rely on rainfall, the amount of seawater in oceans is not affected by changes in weather and there is a plentiful supply.
- The plant will utilise some current Hunter Water infrastructure. The discharge of brine (the remaining saltwater from the desalination process) to the ocean will be via the existing outfall at the nearby Belmont Wastewater Treatment Works.
The water
Water produced through the desalination process will be supplied to Hunter Water's existing water supply network and will comply with the Australian Drinking Water Guidelines.
Our drinking water already comes from different sources – dams, rivers, sandbeds, and bulk water transfers from the Central Coast. The water produced at the Belmont Desalination Plant will be an additional water source for our region.
Desalination nationally and globally
Desalinated water is safe and is already used all over the world, including in America, South America, the Middle East, Africa, South Africa, Europe, and Asia. In Australia, desalinated water is already supplied in Brisbane, Sydney, Melbourne, Adelaide and Perth. Desalinated water plants are also operating in some regional areas, with more planned.
Frequently asked questions
Desalination and the water cycle
Having a desalination plant as an additional water source safeguards our region's water supply into the future. It will become part of our urban water cycle, providing fresh, clean drinking water to our existing network.
Penalties
The penalties for non-compliance and further information can be found on the Public access to dams and catchments page.