Reclamation nation: recycled water can deliver a sustainable, reusable resource

Earlier this month, the central Victorian town of Kyneton opened the taps on a $7.5 million recycled water upgrade to its regional treatment plant.

It’s not for drinking water, but it does mean more high-quality supplies can be committed to that use.

Phase 3 of the $17 million Kyneton Recycled Water Irrigation project will deliver up to 300 megalitres via a new 14km pipeline to local farmers and industry.

It’s the final phase of a project already irrigating the Kyneton showgrounds, soccer fields and racecourse. The water is also being used by the local botanic gardens.

It’s the most recent example of how increasingly frequent and severe droughts have begun eroding Australia’s squeamishness about purifying sewage and recycling water, even for industrial and agricultural uses.

That’s despite countries such as the United Kingdom, United States, Belgium and Kuwait already treating wastewater to replenish reservoirs and ground-water systems used for drinking purposes. And more nations are investing in purification infrastructure in light of UNICEF’s warning that climate change is already unbalancing weather patterns in ways that lead to “unpredictable water availability”.

Waste not, want not

Water scarcity is nothing new in regional Australia.

Victoria, for example, has had a Sustainable Irrigation Program operating for the past 30 years. Its goal is to maintain and improve agricultural irrigation supplies in regions such as the Goulburn Murray Irrigation District, the Victorian Mallee region, the Macalister Irrigation District, and areas in the state’s northeast and south-west.

But, as the Murray-Darling Basin and Great Artesian Basin demonstrate, there is very little slack left in the system.

That means doing more with less.

And cleaning up poor-quality water has become a high priority nationally.

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“Tertiary-level water treatment can turn water from a scarce single-use resource with ongoing demand into a sustainable, reusable resource,” says CSIRO’s Dr Ramesh Thiruvenkatachari.

That, he says, includes treating water at mines and other industrial infrastructure. And finding technologies that can exploit renewable energy for the recycling process in remote areas is his area of research.

He says that water quality is a severe problem for such heavy industrial sites, even during periods of heavy rainfall. Unwanted overflows could pollute the surrounding environment.

“Improved efficiency of on-site water treatment technologies is critical to reduce the storage levels of mining and industrial wastewater,” Thiruvenkatachari says.

“Sometimes the industrial wastewater can be beneficially used in agricultural irrigation – depending on its characteristics,” adds the project’s principal consultant, Graham O’Brien.

Think local

The Kyneton project was initiated in 2019 to purify wastewater from 7500 users from the town and the surrounding centres of Malmsbury, Trentham and Tylden before it reached the Campaspe River. But some of that water is now being reclaimed to irrigate 60ha of dry farmland.

“This pipeline is a fantastic smart use of recycled water to boost agricultural production in our region, and is a demonstration of our commitment to sustainable and beneficial reuse options for our recycled water,” says Coliban Water spokesman Danny McLean.

The new pipeline delivers Class C water. That means it has been decontaminated sufficiently for use with trees, flowers, and certain food crops. It also suits industrial wash-down, sports field turf and community green spaces.

Direct human contact, however, must remain limited.

The first beneficiary is Crofton Park in the South Grampians. The property will use the recycled water to produce clover as livestock feed.

“The property was selected after a land capability assessment and a commitment from the owner to partner with Coliban Water over the long term,” says the Federal Department of Environment and Water.

“Under the agreement, on-farm infrastructure will be installed including pivot irrigators, pumps, pipes and land preparation, which will provide water security for summer crops.”

Other farms along the pipeline will also be connected to the irrigation supply.

Opening the floodgates

Recycled water is already attracting significant state and federal government investment.

Sydney Water’s Upper South Creek Advanced Water Recycling Centre (AWRC) will begin treating about 70 megalitres daily by 2026 for use in suburban Western Parkland City. Meanwhile, Brisbane’s Western Corridor Recycled Water Scheme has been feeding cooling water to local power stations and recharging Lake Wivenhoe’s drinking water reserves since 2008.

A new CSIRO trial is underway in Tamworth, north-west NSW, improving wastewater recycling at the local abattoirs.

“It facilitates more efficient, low-cost recovery of usable water for other beneficial purposes within the industry operation and in the wider environment,” says Dr Thiruvenkatachari.

Drinking water, a group of Australian academics says, will have to be the next goal.

“City residents have come to expect abundant water from sources they perceive as ‘pure’: dams, aquifers and desalination,” argue the authors behind the book Cities in a Sunburnt Country.

“Continuing down this path is not sustainable.”