Recycled wastewater will soon supply 10 per cent of Perth's annual water needs

Recycled wastewater will soon supply 10 per cent of Perth's annual water needs

Securing our most precious resource

Securing our most precious resource

Sustainability
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Mark Twain famously said "whiskey is for drinking, and water is for fighting over".

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With drought gripping much of the nation and the climate becoming increasingly unpredictable, it's becoming crystal clear that water is our most precious resource.

Some of the best and brightest minds have been working on innovative and creative solutions to some of the biggest water problems - the first of which being, how do we get more of it?

For a long time, there has been a "yuck factor" attached to recycling and treating waste water to a drinkable standard.

But with drought gripping large sections of the nation, delegates and residents alike are becoming more open to the idea.

University of NSW water expert, Professor Khan, said when it came to recycling water, "there is more than one way to skin a cat".

"There's a whole bunch of recycling water programs around the world, and they're all different," he said.

"They're uniquely designed taking into account local circumstances.

"This is a serious discussion. Cities need a solution to dwindling water supplies, and this is one of them."

Perth is Australia's poster boy for recycling wastewater. In simple terms, the Western Australia capital takes sewage, treats it and uses it to recharge an underground aquifer.

It currently recycles 14 gigalitres annually, and when stage two of the project is completed later this year, that will double to 28 gigalitres, or 10 per cent of the city's yearly use.

The Perth model purifies wastewater three times, before pumping it into an aquifer that already supplies the city, where it is naturally filtered again.

It is later extracted and pumped to a water treatment plant.

A small-scale solar farm is helping Narromine farmers access deep groundwater for irrigation.

A small-scale solar farm is helping Narromine farmers access deep groundwater for irrigation.

It's a very effective system, however it relies on two important factors - an aquifer and being on the coast, so the salt extracted from the recycled water can be injected into the ocean.

But there are alternative methods for inland cities who don't have an aquifer, but want to do something similar.

"Usually inland cities use ozonation, which involves a very powerful disinfectant, more powerful than chlorine, that kills germs and pathogens," Professor Khan said.

"It also starts to break down organic chemical compounds. Then the water is filtered through activated carbon, which filters out the organic compounds."

Because that process doesn't remove the salt, it has to be blended with another water source, such as a dam.

"It would be the cleanest water going into the reservoir," Professor Khan said.

Singapore and a number of states in America, including Virginia and Georgia supplement their reservoirs with recycled water.

The Beaufort West region in South Africa uses an 80/20 split of treated reservoir water and recycled water, which is blended together.

The regional NSW city of Orange has a world-class stormwater harvesting scheme, which uses wetlands to help naturally filter the water and provides up to 25 per cent of the city's annual supply.

Read more: Orange uses wetlands to filter and recycle stormwater

Unlocking the full potential of underground aquifers is another area being explored.

Many farmers already know the value of underground water, with most having at least one bore on their property.

But in some places, the water is so deep, getting large amounts to the surface can cost a small fortune in power bills.

That was the problem Narromine irrigators Karin Stark and Jon Elder faced.

"Our energy cost was the highest cost on property," Ms Stark said.

"We were spending so much on diesel to power the irrigator pumps and we were subject to any fluctuation in the price of diesel - if it went up, we had no choice but to pay for it."

So to counter the problem, they've built the largest privately-owned solar energy station in the Southern Hemisphere, which is connected to their groundwater irrigation system.

The 500-kilowatt solar farm is powered by 1550 panels and provides enough power to pump 15 megalitres a day.

"It's got a five-year payback and it's allowed us to take back control," Ms Stark said.

Eric Vanweydeveld designed a water treatment plant out of shipping containers for a remote community in the Northern Territory.

Eric Vanweydeveld designed a water treatment plant out of shipping containers for a remote community in the Northern Territory.

With rain events and climate conditions predicted to become more unpredictable into the future, Ms Stark said the combination of water and renewable energy made sense.

"There is a really strong business case for combining the use of renewables and water," she said.

"As drought conditions are expected to prevail with climate change, irrigator agriculture is going to become more and more important.

Looking for cleaner, sustainable energy sources, that aren't going to make farmers go out of business through exorbitant costs, is the way forward."

Technology and outside-the-box thinking may well be the answer to many of our water problems. Take for example the extremely remote Northern Territory town of Borroloola.

The water treatment plant, made of five shipping containers, will secure Borroloola's water supply for the next 30 years.

The water treatment plant, made of five shipping containers, will secure Borroloola's water supply for the next 30 years.

Located about 1000km south-east of Darwin in the Gulf of Carpentaria, it desperately needed a water processing plant to treat its acidic groundwater.

However, getting equipment and labour out to such a remote location was a huge barrier.

Engineer Eric Vanweydeveld came up with an idea. He and his team designed the plant using five shipping containers.

They were able to fit out the containers in Darwin, then put them on a train and install them with minimum effort in Borroloola.

The cost-effective solution has secured the town's supply for the next three decades, and it could be rolled out to other remote locations.

"The model is there and the blueprint is there," Mr Vanweydeveld said.

"They are now looking at the model for other cities in central Australia."

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