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General Information

 

Why do we have a desalination plant?

 

Why is desalination important?

 

Who do we supply?

 

What is the process of desalination?

 

What happens to the brine that comes from running desalination?

 

How much energy does the plant use?

 

What is the impact on the environment?

 

How does the desalinated water taste?

Drought response and benefits

 

Can the plant be turned on to help drought affected farmers in country NSW?

 

For how long will the plant be operational once the dam levels reach 60% and when the dam levels reach 70% will we have to wait for the dam levels to fall to 60% before the plant starts again?

 

Is it correct that there is no prospect of drinking water from the plant for another 12 months?

 

Will we have to wait for the dam levels to fall to 60% before the plant starts again?

 

How many extra jobs are created when the plant is operating compared to water security mode (mothball)?

Costs

How much does the plant cost during water security mode and when it is operating?

 

Why is it so expensive to keep the Plant in a state of readiness even when it isn’t producing water?

Storm

Was there a dispute with SDP insurers in regards to the reinstatement of December 2015 storm damage?

 

Who paid for the reinstatement of the plant after the storm event?

 

What was the process of returning the Plant to service after the storm? Did just a few roofs blow off? Why isn’t it ready to go now?

Restart

Why does it take 8-months to restart the Plant, particularly given the ongoing cost of keeping the Plant in a state of readiness?

 

Why is there an additional cost to restart and shut down the Plant?

 

How much carbon dioxide is emitted by the energy needed to power the plant at full production?

 

 

 

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General Information

 

FAQs

Why do we have a desalination plant?

Sydney's Desalination Plant is one effective way of securing Sydney's water supply against the effects of climate change, population growth and drought. Desalination is part of the Metropolitan Water Directorate's Water 4 Life Scheme, along with dams, recycling and water efficiency programs. The plant is powered by 100% renewable energy and can supply up to 250 million litres of water a day, which is approximately 15% of Sydney's water needs. The water provided by the desalination plant benefits all water users in Sydney either directly or indirectly.

 

Desalination turns seawater into drinking water. Many countries around the world use desalination as a way of creating a more reliable source of water that does not depend on rain.

 

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Why is desalination important?

Desalination is important because it is the only non rainfall dependent direct source of drinking water. Sydney has highly variable rainfall. The Sydney Desalination Plant ensures that Sydney has a secure source of drinking water for now and in the future. Along with dams, recycling and water efficiency programs, desalination can help protect against the impacts of drought, population growth and the effects of climate change. 

 

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Who do we supply?

 

Sydney Desalination Plant can supply water to up to 1 .5 million people south of Sydney Harbour and as far west as Bankstown, as part of all of their water supply.

 

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What is the process of desalination?

Desalination is the process of removing dissolved salts and other particles from seawater. Sydney Desalination Plant is powered by 100% renewable wind energy and uses reverse osmosis to extract fresh water from seawater. The plant contains over 36,000 reverse osmosis membranes which, under pressure, filter out particles and salts, so that fresh water can pass through, leaving the seawater concentrate to be returned to the ocean.

 

Pre-treatment of seawater

  • Seawater flows into the plant under gravity, through a large pipe.
  • Large screens are used to filter out debris down to 3 milimetres in diameter
  • The Seawater is then filtered through sand and coal to remove even smaller particles

 

Desalination - Reverse osmosis

The very clean 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 seawater concentrate is left behind. Approximately 42% of the seawater becomes drinking water.

 

Drinking water

The fresh water produced by the Sydney Desalination Plant is treated to meet the Australian Drinking Water Guidelines. Fluoride is added to protect teeth, as is done with all of Sydney's water.

 

The drinking water then travels through an 18 kilometre pipeline to join the Sydney Water supply network at Erskineville. It can supply up to 1.5 million people south of Sydney Harbour and as far west as Bankstown.

 

Seawater concentrate

The remaining seawater concentrate is about twice as salty and about one degree warmer than the ocean. It is returned through a large pipe that lies beneath the seabed. The seawater is dispersed using specially designed diffusers which return the seawater concentrate to normal salinity and temperature within 50-75 metres from the outlet point. 

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What happens to the brine that comes from running desalination?

Approximately 58% of the intake seawater is returned to the ocean as seawater concentrate or brine. The seawater concentrate is about twice the salinity and one degree warmer than the ocean. 

 

The seawater concentrate flows through the outlet tunnel and is dispersed deep in the ocean through specially designed diffuser nozzles attached to the outlet risers. The seawater concentrate returns to normal temperature and salinity within 50-75 metres of the outlet.

 

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How much energy does the plant use?

The Sydney Desalination Plant requires roughly 38 Megawatts at full production. The energy it consumes is equivalent to the energy consumed by a domestic fridge if all of the water used in the household was supplied from our desalination plant.

 

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What is the impact on the environment?

SDP places a high priority on minimising any environmental impacts - both on land and in the water. To support this, SDP has put in place one of the most stringent marine environment monitoring programs of its kind. The marine environment was monitored for three years before construction and for three years after commissioning.

 

The Marine and Estuarine Monitoring Program (MEMP) has also been a strong focus of the SDP. Research has shown that, once dishcarged to the ocean, the seawater concentrate returns to normal temperature and salinity within 50 - 75 metres from the outlet. This is called the near field mixing zone. It has been found that there are no significant impacts on seawater quality or aquatic ecology from the seawater concentrate beyond the near field mixing zone and minimal impact within near field mixing zone.

 

On land , a third of the plant site at Kurnell has been kept as a conservation area. This area is protected and native species of flora and fauna are regularly monitored. This includes a program to survey the numbers of grey headed flying foxes and green and golden bell frogs in the area.

 

The Capital Hill Wind Farm at Bungendore produces more than enough energy to offset the power needs of the desalination plant and is an environmentally friendly way to supply the power needs of the Sydney Desalination Plant. 

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How does the desalinated water taste?

Sydney Desalination Plant water is treated to taste the same as Sydney's other drinking water sources. Like dam water, water from the desalination plant is treated to meet Australian Drinking Water Guidelines, which makes it among the best in the world. 

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Can the plant be turned on to help drought affected farmers in country NSW?

 

Drinking water from our plant is delivered into the Sydney Water network via our dedicated pipeline under Botany Bay and into the Sydney Water system at Erskineville.

 

Trucking water to drought affected areas is not a matter that SDP has expertise to assess or authority to recommend.

 

Whereas it would be theoretically possible to fill water tankers at our site and drive them into the affected farming areas the cost of doing this is massively prohibitive.

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For how long will the plant be operational once the dam levels reach 60%? When the dam levels reach 70% will we have to wait for the dam levels to fall to 60% before the plant starts again?

 

The rules that determine when the desalination plant operates are contained in the government’s 2017 Metropolitan Water Plan. Under this Plan, the “trigger” to commence the restart of the plant occurs when combined water storage levels in the major dams fall below 60 per cent and then operate until storage levels recover to 70 per cent.

 

Should storage levels again fall below 60%, the plant will commence restarting 

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Is it correct that there is no prospect of drinking water from the plant for another 12 months?

 

No this is not correct. The desalination plant has already commenced early preparations for restarting the plant. If the dam storages fall to the 60% water storage level trigger to restart the plant, we expect water would start to be delivered into the drinking water system after four months. It will take between six to eight months after being switched on for the plant to reach its maximum capacity of producing 250 million litres per day of water – or about 15 per cent of Sydney’s drinking water.

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Will we have to wait for the dam levels to fall to 60% before the plant starts again?

 

The rules that determine when the desalination plant operates are contained in the government’s 2017 Metropolitan Water Plan. Under this Plan, the “trigger” to commence the restart of the plant occurs when combined water storage levels in the major dams fall below 60 per cent and then operate until storage levels recover to 70%.

 

The desalination plant has already commenced early preparations for restarting the plant.

 

If the dam storages fall to the 60% water storage level trigger to restart the plant, we expect water would start to be delivered into the drinking water system after four months.It will take between six to eight months after being switched on for the plant to reach its maximum capacity of producing 250 million litres per day of water – or about 15 per cent of Sydney’s drinking water.

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How many extra jobs are created when the plant is operating compared to water security mode (mothball)?

 

The plant was placed into what is known as “water security” mode in 2012, after two years of successful operation. Since then, the plant has been in a deep state of preservation, to minimise the cost to Sydney Water customers of maintaining the plant while it is not operating. During this time, the plant has required around 17 employees to maintain the plant and pipeline.

 

A restart requires the plant to be effectively recommissioned. This will require the employment of required specialist and trained employees for full operation. We expect the workforce on site to increase to around 40 people.

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How much does the plant cost during water security mode and when it is operating?

 

The cost for operating and maintaining the desalination plant are determined and regulated by a NSW independent regulator (IPART).

 

The regulated cost of producing water is paid for under a separate charge as and when delivered to Sydney Water customers.

 

The owners of the Sydney Desalination Plant paid $2 .3 billion to the NSW Government for a long-term lease of the plant and pipeline.

 

These prices are fully transparent and can be found on links on this website under the Regulatory section and also on the IPART website.

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Why is it so expensive to keep the Plant in a state of readiness even when it isn’t producing water?

 

The SDP is an integral part of the Sydney water system, helping to ensure that Sydney always has sufficient water to meet the needs of residential and commercial customers, especially in times of drought.

 

Since the plant was placed in “water security” mode in 2012, the plant has been in a state of preservation.

 

Even in “water security” mode, the Sydney Desalination Plant and its pipeline, remains a large, complex and highly valuable asset that requires a sustained care and maintenance program. This ensures the plants’ structure and pipeline is in the best position to respond as quickly as practicable to deliver a reliable supply of high quality water.

 

The cost for operating the desalination plant are determined and regulated by a NSW independent regulator (IPART). More information about the framework for determining the costs of the plant can be found on the IPART website here.

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Was there a dispute with SDP insurers in regards to the reinstatement of December 2015 storm damage?

 

No. The claim made by SDP for recovery of tornado storm damage costs back in December 2015 was conducted very professionally by our insurance panel. The settlement of the complex claim has allowed SDP to fully repair the storm damage and, importantly, with no cost pass through to Sydney Water customers.

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Who paid for the reinstatement of the plant after the storm event?

 

The storm across Sydney in December 2015 was rated by the Bureau of Meteorology as a strong tornado that caused considerable damage to property, vehicles and vegetation in Kurnell, including damage to the Sydney Desalination Plant. While the plant was designed to sustain extreme weather conditions, the wind gusts of 213km/h were recorded at Sydney Airport were well above any maximum wind gust recorded in NSW.

 

SDP undertook a comprehensive process with the company’s insurers and secured a mutually agreeable arrangement that saw all the costs of rebuilding and testing the plant for rebuild defects fully covered by the insurers.

 

The rebuilding of those parts of the plant that were damaged by the severe storm is now complete. Sydney Water customers did not pay any of the rebuilding costs as these were covered by SDP insurance.

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What was the process of returning the Plant to service after the storm? Did just a few roofs blow off? Why isn’t it ready to go now?

 

The storm across Sydney in December 2015 was rated by the Bureau of Meteorology as a strong tornado. The storm damage to the Sydney Desalination Plant was widespread around the 45 hectare site. In fact, SDP insurers likened the damage to what is typically expected following a significant earthquake.

 

The rebuilding of those parts of the plant that were damaged by the severe storms is now complete.

 

The process SDP followed was:

 

  • Agree the repair program with the NSW government
  • Clean up the site following the storm event
  • Scope the damaged plant and equipment – what was destroyed and what could be repaired. This included a review of over 28,000 individual assets on the site
  • Run a competitive tender process with two potential rebuild companies and negotiate an acceptable price and contract structure. Assemble of team of owner’s engineers and independent verifiers to oversee the rebuild works
  • Manage the rebuild works (December 2016 through to May 2018)

Test parts of the plant that were damaged and repaired by the SDP construction company (expected completion September/October 2018).

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Why does it take 8-months to restart the Plant, particularly given the ongoing cost of keeping the Plant in a state of readiness?

 

In 2012, the Sydney Desalination Plant was placed into what is known as “water security” mode, after two years of successful operation. Since then, the plant has been in a state of preservation to minimise the cost of maintaining the plant while it is not operating. The annual cost savings from the shutdown activities is passed through to Sydney Water customers through reduced cost allowances under the IPART price determination.

 

Even in “water security” mode, the Sydney Desalination Plant and its pipeline, remains a large, complex and highly valuable asset that requires a sustained care and maintenance program. This ensures the plants’ structure and pipeline is in the best position to respond as quickly as practicable to deliver a reliable supply of high quality water.

 

The rules that determine when the desalination plant operates are contained in the government’s 2017 Metropolitan Water Plan. Under this Plan, the “trigger” to commence the restart of the plant occurs when combined water storage levels in the major dams fall below 60 per cent and then operate until storage levels recover to 70 per cent.

 

A restart requires the plant to be effectively recommissioned. This includes activities such as:

 

  • Labour – employ the required specialist and trained staff for full operation of the plant.
  • Chemicals – sourced both locally and overseas.
  • Reverse osmosis membranes – replacement. These membranes are sourced from a few specialist suppliers overseas and are manufactured to order so lead times can be extended as a result.
  • Testing of the plant – testing all components, subsystems and systems.
  • Disinfecting the 18 km delivery pipeline.
  • Soaking all the concrete structures in the plant prior to the ingress of seawater.
  • Uncapping the seawater inlet tunnels to allow seawater into the plant.

 

Finally the plant needs to be sequentially restarted and allowed to stabilise for a few weeks to ensure that the water chemistry is at a high and reliable level for delivery into the drinking water system.

 

All of the above activities involve significant time to achieve from the plant’s current  deep state of preservation, hence the eight months required to complete a restart.

 

We are acutely aware of the importance placed on the Sydney Desalination Plant to help to ensure that Sydney has sufficient water to meet the needs of residential and commercial customers, especially in times of drought. We will do everything possible to minimise the time taken to bring the plant into full production.

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Why is there an additional cost to restart and shut down the Plant?

 

The costs of restarting the plant and returning it to shutdown at the end of a period defined by the Sydney Metropolitan Water Plan have been determined by the independent regulator IPART and are paid once per drought cycle.

 

More information can be found on the IPART website here

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How much carbon dioxide is emitted by the energy needed to power the plant at full production?

 

The Sydney Desalination Plant uses 100% green power purchased from a wind farm company as an offset for all energy consumed on site at all times, even when in preservation mode. Therefore, the electrical energy footprint of the process is zero carbon emissions.

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