Water Secure - South East Queensland WaterSecure Water Secure. Queensland Manufactured Water Authority Gold Coast

Gold Coast Desalination Plant

Desalination explained

The facts

Environment

2008 tunnelling and marine barge 08 09 12

2009 tunnelling and marine intake structure 1

2009 tunnelling and marine outlet structure 24

Fact vs fiction

The Gold Coast Desalination Plant is securing water for South East Queensland and is the largest desalination plant on the Eastern seaboard. As with any project of this size, there is strong interest in its operations and this section provides information on common questions and misconceptions.

The desalination plant is not running/has barely been functioning.
The plant has been operational since February 2009. It is designed to run at 0, 33, 66 and 100 per cent capacities and does so according to instructions from the Water Grid Manager.

It has passed its reliability trial and has supplied over 17 billion litres to the water grid as at December 2009. At full capacity the plant produces enough water for 650,000 residents under Target 200 water restrictions.

The budget for construction of the desalination plant has blown out.
The desalination plant remains within its budget of $1.2 billion.

The desalination plant is an ugly, permanent structure located in the ocean.
The structure seen in the photograph on the left is not a desalination plant – it is the barge that was used for construction of the marine structures. It was used between April 2007 and November 2007, and then removed returning in March 2008 for another 8 month period after which is was taken away permanently.

The actual desalination plant is located on land at Tugun next to the Gold Coast airport. As it is the first thing many visitors to the Gold Coast see, it has been designed as an attractive industrial building that doesn’t detract from the tourist region’s visual appeal.

Desalination is highly energy intensive.
Modern desalination plants use advanced technology and energy saving devices which result in being far less energy intensive than traditional plants.

The Tugun plant has recently recorded energy consumption figures better than expectations, resulting in savings of more than 27 000 tonnes of carbon dioxide a year, further reducing its carbon footprint as well as energy costs. In comparison, one jumbo jet engine uses approximately the same energy required to power the desal plant at full capacity and jumbo jets can not use renewable energy.

The plant’s innovative use of energy saving devices — which recover up to 97% of the unused energy from the brine — combined with carbon offsets and reduced energy consumption put it among the best performers in terms of energy for desalination plants worldwide.

How much power does the Desal plant use?
Much has been made of the power consumption of a desalination plant but how much energy does a plant use to produce drinking water? And what does this mean at the household level?

The Gold Coast Desalination Plant has the capacity to produce 133 million litres of drinking water a day. To produce a million litres of water, the plant consumes about 3.1 megawatt hours (MWh) of energy. So at full production, the plant consumes about 412.3MWh of energy per day, making it the most energy-efficient desalination plant in the world.

At full capacity, the plant produces enough water for 665,000 people consuming water at Target 200 levels, enough water for about 260,000 households. About 1.59 kilowatts (kWh) of energy per day is consumed to produce water for each household. At the standard household tariff, this energy would cost a household around 27 cents a day, or $99.62 a year.

But nowhere in South East Queensland does anyone receive 100% desalinated water – it is always blended with treated dam water. Typically about 10% of the water that comes out of South East Queensland taps originates from the desalination plant. So energy cost per household that receives desalinated water is more like 2.7 cents a day – less than $10 a year.

So how does this compare to the cost of running common household appliances? The table below uses figures from the Australian Government and the results are surprising.

* www.energyrating.gov.au

These figures put in perspective the energy consumption of non-essentials like TVs and air conditioners against the essential need to have clean drinking water. At an energy cost of just 2.7 cents a day, the desalinated component of our water supply is good value for a supply that isn’t affected by drought and is available rain, hail or shine.

And despite running the world’s most energy-efficient desalination plant, WaterSecure recognises the plant does consume considerable quantities of energy and this energy has greenhouse gas implications. So WaterSecure has purchased Renewable Energy Certificates (RECs) to fully offset the plant’s energy use, making the Gold Coast Desalination Plant the greenest desalination plant on earth.

The desalination plant is not run on renewable energy.
In August 2009 renewable energy certificates were purchased on behalf of the plant which will see the plant offset its carbon emissions for about 18 to 20 months of operations, depending on the precise operating schedule which is determined by the Water Grid Manager.

The desalination plant vibrates.
The plant does not vibrate when it operates and studies undertaken during construction showed vibration levels to be well within acceptable limits. There is, however, vibration from the airport next door when aircraft take off and land.

Damage to homes potentially caused by construction of the pipeline has not been repaired.
A commitment was given by the GCD Alliance and the Queensland government that any damage to property caused by construction activities would be reinstated.

Pre- and post-construction reports were carried out by independent organisations and residents were advised of their rights. The Alliance considers all these issues to now be closed. WaterSecure is happy to review any independent evidence offered to support claims of damage.

Construction of the desalination plant caused damage to the Tugun Rugby Leagues Club.
Vibration monitoring was carried out during construction and no exceedance of acceptable limits was found.

The Tugun Rugby Leagues Club was built on landfill, much of which is decaying and causing ground movement. Droughts followed by heavy rains may have caused further changes in ground conditions, exacerbating the unstable ground conditions.

The Alliance has undertaken works worth more than $2.6 million to reinstate and upgrade the Betty Diamond Sporting Complex. This includes more than $600,000 in support provided to the Tugun Rugby League Club which involved providing a new level, properly constructed field with irrigation and an additional third field, also properly constructed with irrigation.

In discharging the requirements of its vegetation clearing permit, the GCD Alliance has provided $500,000 to the Gold Coast City Council. In doing so, the Alliance, WaterSecure and the Queensland Government made clear their strong preference that a substantial portion of this funding go to assistance to the Rugby League Club. Council has agreed that $250,000 will be allocated to provide this assistance.

Desalinated water causes dry skin and hair.
Claims were made by a resident of the Southern Gold Coast that desalinated water was leaving her hair and skin dry. Desalinated water does not currently go to residents living on the southern Gold Coast. It is, however, blended with water sourced from dams and distributed to consumers on the middle and northern sections of the Gold Coast and in Brisbane.

In any case, water from the Gold Coast Desalination Plant is remineralised after the reverse osmosis process so that its composition is similar to water sourced from local dams.

The desalination process produces salt which is discharged to the ocean.
No salt is produced by the desalination process.

About half the water taken into the plant is turned into fresh drinking water, this involves removing salt. The salty other half flows back to the ocean where it is dispersed rapidly and safely. The quality of this water is monitored continuously and the quality of the water and sediments near the underwater outlet are tested regularly as a condition of the plant’s environmental licence.

The desalination plant is rusting.
Signs of early corrosion were found in some components (valves and couplings) but these have all been replaced. Pipework that showed signs of corrosion is being replaced with high grade stainless steel. The plant is able to operate safely at full capacity until this work is completed next year. Because seawater is highly corrosive, regular inspections and maintenance will continue throughout the plant’s life.

The size of the Gold Coast Desalination Plant was quadrupled.
The desalination plant was originally scoped to be a 55 megalitre/day facility. As the drought progressed and the Queensland government became involved in the project the design was expanded to 125 megalitres a day, just over double the original capacity. There are no plans to increase the capacity of the plant.

We don’t need the desalination plant.
We need water for our growing population. Climate change means we can no longer rely on rain for all the water we need. Unlike dams, water recycling and desalination provide water – rain, hail or shine.

The community has not been consulted regarding the project.
An extensive community engagement process was conducted that involved every aspect of the project - from the feasibility study phase through to construction. Scores of presentations have been given to the community and fact sheets, project newsletters and website information have been produced. Furthermore, a Community Reference Group (CRG) which included a range of community interest groups was held monthly during the peak construction period. A new GCDA Project Information Centre located at Boyd Street Tugun was open from April 2007 to December 2008 when major construction work drew to a close.

If you have any questions not answered here or require further information please contact us on info@watersecure.com.au or 1300 366 190.

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