Daryl Passmore
April 20, 2008

A WATER source has been discovered that could supply parched parts of Queensland with billions of litres every year for decades.
The coal-seam gasfields being developed by the Queensland Gas Company in the Surat Basin near Condamine will produce enough water to meet nearly a quarter of Brisbane’s annual needs for at least 30 years, the company’s experts say.

For Queensland Gas, the water is a “waste product” that has to be removed to stimulate the gas flow.

But to a state hit by prolonged drought and facing increasing threats from climate change, it’s liquid gold.

“Sometimes it’s important to lift your eyes and look at the bleeding obvious,” said Queensland Gas managing director Richard Cottee.

Billions of litres could be used to supply Toowoomba and rural communities west of the city – or piped to Wivenhoe Dam.

With only a tenth the salinity of seawater – “it’s just brackish to taste” Mr Cottee said – the coal-seam water could be brought to drinking standard through filtration by reverse osmosis or other methods.

The company has already signed a deal with the former Miles Shire Council to supply the town with all its potable water for free. The council will build an 8km pipeline.

It was only in February that the full scale of the reserves was realised.

Once the gasfields hit full production, in about seven or eight years, a massive 100 to 125 megalitres of water a day will be pumped out – the same amount that will be produced by the $1.1 billion desalination plant being built at Tugun on the Gold Coast.

While Queensland Gas would own the water, Mr Cottee said the focus would be on recovering the costs of getting the water to where it was needed rather than exploiting it as a revenue stream.

“We are a gas producer,” he said. “The water will be our waste product. It’s ridiculous isn’t it – in the driest continent on earth, water will be waste. It’s too precious to waste.”

Mr Cottee has spoken with Premier Anna Bligh about the potential.

One idea is to construct a water pipeline alongside the Roma to Brisbane gas pipeline.

This could supply Toowoomba and a string of drought-hit towns including Miles, Chinchilla, Dalby and Oakey.

The company estimates the cost of a 180km pipeline from the gasfields to the Garden City would be about $300 million.

But it would eliminate the need for the Government to go ahead with a planned $200 million pipe, which would pump scarce water the other way from Wivenhoe up the Great Dividing Range to Toowoomba.

Premier Bligh said: “If the water can be treated effectively and then transported efficiently, I would like to get this as drinking water to regional towns and Toowoomba.

“But this could also be an excellent source of reliable water for farm irrigation, cattle feedlots and industrial uses such as power stations.”

Ray Brown, mayor of the Dalby Regional Council, said the water supply “would be a huge benefit for our region” boosting agriculture, mining and other development.

“I’m very excited. Everyone out here is on the edge of their seats at the moment.

“We’ve been in drought fo so long and people have been down, but now everyone has a spring in their step.”

Another option – particularly once a second field for Queensland Gas becomes operational, doubling the amount of water produced – could be to extend the pipeline to feed Wivenhoe Dam to help meet the needs of the southeast. The lower-quality discharge residue could go to Tarong Power Station.

The water, like the gas, is molecularly held within the coal and has to be extracted to break a pressure seal that releases the gas.

“This is important because it means the water could otherwise not be accessed,” said a Queensland Gas spokeswoman.

“It is not in aquifers or groundwater supplies, but structurally bound inside the coals. So removing it will not lower the underground water table.”

Up to 30 megalitres of water a day is already being extracted from the coal and stored in massive dams at the gasfields. The company expects that to rise to between 100 and 125 megalitres daily within five years.