What is desalination?
The NSW Government has proposed seawater desalination as a solution to our water shortage problems. ‘Desalination’ is a process whereby sea water is made ‘drinkable’. It works by removing dissolved minerals (including, but not limited to salt) from seawater, salty water or treated wastewater.
Why is it happening?
According to the NSW Government, the ongoing drought has shown that an alternative source of fresh ‘drinking’ water needs to be implemented to accommodate Australia’s dry periods. The desalination plant will be able to deliver 500 million litres of drinking water a day; that’s water for a third of Sydneysiders. The government believes that this is the most viable and reliable method to quench the thirst of Sydneysiders during drought periods. It also provides assurance that measures and research will be undertaken to ensure that the plant will cause minimal harm to our environment and marine ecosystem.
Desalination is generally done in one of two ways:
1. Distillation: this is where sea water is heated so that the water evaporates and separates from the salt.
2. Reverse osmosis: this technique essentially works as a filtration system.
Sydney’s desalination plant will use the latter technique. It has proven to be a more cost and energy effective method of desalination.
Where is it being implemented?
In Sydney the plant is being constructed in an industrial area of Kurnell in the Sutherland Shire. The Kurnell peninsula has a rich heritage—parts of it, including Botany Bay National Park, are listed as National Heritage. However, the site for the plant has been zoned for industrial purposes (there’s a Caltex oil refinery nearby) and the government maintains that the area does not encroach on the National Park.
Other parts of Australia (the Gold Coast, Melbourne and Adelaide) are also looking to desalination. Perth’s desalination plant has been operating since November 2006, and they are set to build a second. Desalination also exists in other parts of the world, like the Middle East, Europe and North America.
When will it happen?
Work began on the project in August 2007. Sydney Water has contracted with Blue Water Joint Venture to build the project. If all goes well, the plant will be switched on and pumping by summer 2009 or 2010.
Do we really need it?
Some critics believe the water crisis is over. Chris Hartcher (Liberal MP) claims “now there’s evidence we don’t need it to go ahead”. In September 2008, Sydney’s dam levels hit 65.8% with more rain expected. Hartcher believes that stormwater harvesting and large-scale water recycling are better options, especially since Sydney’s water consumption levels are the lowest they have been since 1974.
However, ex Water Utilities Minister Nathan Rees (now premier of NSW) believes the plant will prepare Australia for future droughts: “You don’t turn around 100 years of droughts with a couple of weeks of good rain”.
What and who will this affect?
Critics claim that the desalination plant could adversely affect the environment, marine biology and even consumers. But the NSW government is still fighting for its decision from all angles.
- Desalination requires heaps of energy. Increased greenhouse gas emissions could put a strain on the environment due. The WWF (World Wide Fund for Nature) believes that desalination would make global warming worse and renewable energy should be used (if the plans must go ahead). A report by the Australian Institute claims that if the desalination plant is supplied with electricity from the state's existing coal-fired power stations, emissions from the plant would be equal to putting another 220,000 cars on the road.
- According to Sydney Water, Sydney’s desalination plant will be run on 100% renewable energy sources. Power will be generated via wind farms. This means the plant should have no greenhouse impact. The aim is to create enough renewable energy to balance any electricity used.
Consumers and taxpayers (YOU)
- Seawater will be collected using a very large vacuum, which could trap and kill marine organisms.
- The government has promised that it will implement ‘a careful screening process’ to protect the marine environment and slow down the rate of the water intake to minimise the chances of fish being caught in the intake structure.
- Concentrated brine is a waste product of desalination. It can disrupt the marine ecosystem if it is expelled into the sea. This means it could harm, or even destroy many marine organisms.
- The government has stated that the brine will be disposed of in such a way so that it will be quickly dispersed and diluted into the sea, to protect the marine ecosystem.
- The construction of the desalination plant will take two years and will cost $2 billion, not including maintenance once it’s up and running—a considerable investment! In addition, it appears that it will cost us more money to use this water and the amount could double if you’re a high-volume consumer.
- The government hopes to make desalination greener and cheaper by spending $7.6 million on research over the next three years. The aim of this project is to find new materials that will halve the power needed for desalination, making it kinder to the environment and your wallet.
This page was updated by kate elise
How do I know this?
ABCNews, 2007, ‘Conservationists warn of dangers of desalination’, ABC, 19 June, http://www.abc.net.au/news/stories/2007/06/19/1955732.htm
ABCNews, 2007, ‘NSW Govt signs desalination contract’, ABC, 25 July, http://abc.net.au/news/stories/2007/07/25/1987658.htm
Australian Water Association, 2007, Desalination, AWA, http://www.awa.asn.au/
California Coastal Commission 1993, Seawater Desalination in California, http://www.coastal.ca.gov/desalrpt/dchap1.html
Frew, W 2005, ‘Plant threatens to double Sydney water bills’, The Sydney Morning Herald, 20 July, http://www.smh.com.au/news/environment/
Frew, W. & AAP, 2007, ‘Higher dam levels be damned: state pushes desalination’, The Sydney Morning Herald, 22 June, http://www.smh.com.au/news/environment/nsw-opts-for-desalination-despite-higher-dam-levels/2007/06/21/1182019286767.html
Hartcher, Chris, 2008, ‘Nathan Rees Tipped as Premier in Waiting’, The Australian Liberal Party, 4 September https://www.nsw.liberal.org.au/
Macey, R. 2007, ‘Push to slash cost of desalination’, The Sydney Morning Herald, 19 May, http://www.smh.com.au/news/national/push-to-slash-cost-of-desalination/2007/05/18/1178995411726.html
Nature Conservation Council of New South Wales, http://www.nccnsw.org.au
Skatssoon, J 2005, ‘Desalination: taking the plunge’, The ABC, http://www.abc.net.au/science/news/tech/
Sydney Water, 2007, Contract signed for Sydney’s desalination project, Sydney Water, http://www.sydneywater.com.au/WhoWeAre/MediaCentre/MediaView.cfm?ID=386