Shenzhen in China is embracing the "sponge city" concept. Image via Twitter @ErikSolheim

The circular economy has infiltrated the board rooms of Australian and New Zealand water utilities, according to a new report. Now to put these ideas into action.

Bricks made from biosolids (bacteria and urea found in human urine) could play a role in circular water system in Australia that avoids heavy metals, microplastics and other pollutants ending up in our waterways. 

According to a recent Water Services Association of Australia report on water management in a circular economy, organic building materials like this tick several boxes for a circular economy as they can be returned to the biosphere at the end of their useful life. 

The “Bio-Bricks” invention is just one of many interesting technologies identified in the report. Another valuable material that could be extracted from urban waterways for circular economy purposes, WSAA chief executive Adam Lovell says, is hydrogen.

“The water industry should thinking about where in its value chain it could be generating hydrogen,” he told The Fifth Estate

In Western Australia, the state government is backing an innovative project to produce renewable hydrogen and graphite from wastewater.

Earlier this year, Water Corporation and the Perth-based Hazer Group signed a deal to develop the technology invented by University of Western Australia on a commercial scale, which will see biogas from sewage at the Woodman Point wastewater treatment plant turned into 100 tonnes of fuel-grade hydrogen and 380 tonnes of graphite every year. 

Lovell says that the report, which he sees as a “call to action” for the industry, follows the leadership set by European countries on circularity in water management. 

Some European countries are way ahead, he says, with the Dutch looking at ways of recovering cellulose in toilet paper to be upcycled into pavements and other functions. 

Here in Australia, we’re only just starting to look at circular water management practices that are common elsewhere, such as recovering nutrients such a phosphorous from waterways to use as fertilising material. 

Lovell says circularity has long been a part of some aspects of water management, such as recycling wastewater for reuse and capturing biosolids for agricultural and landscaping purposes. But these ad hoc practices are not designed intentionally as part of a cradle-to-grave lifecycle that designs out all waste externalities, he explains. 

“You need to start from the very beginning and design out waste externalities, rather than ending up with waste product and then finding a use for it.”

While technology is key to this transition, sometimes the best solution is letting nature do its thing. 

“Sponge cities”, for example, stop excessive stormwater runoff through permeable surfaces and green infrastructure, helping to manage stormwater, mitigate urban heat and reduce pollution.

A circular approach to water management isn’t too much of a stretch

Lovell says water management is a good place to introduce the notion of a circular economy.

“Water is the most circular of all the economy, it’s not that hard of people to get their heads around it.

“It’s hard to find a more circular business than water. All water on Earth is used and reused in an endless cycle.”

While most people recognise that water moves around the planet in a circular fashion, its typically dealt with in a linear fashion in cities and towns.

The principles of circular water management 

A circular approach to urban water management includes designing for the most efficient amounts of energy, minerals and chemicals used in the delivery of water services.

The circular economy departs from the conventional “take-make-dispose extractive industrial model” by firstly reducing consumption through efficiencies (preventing leaks, installing water efficient appliances, etcetera). The next step is to capture useful materials for another use.

Finally, and fundamentally, water management practices need to move beyond harm minimisation to actually “doing good” by regenerating natural ecosystems.

“The paper recommends we need to move beyond ‘sustaining’ to ‘restoring’ the material balance and then actively go further with ‘regenerative’ actions that will ensure the planets health, resilience and ability to adapt,” Lovell says. 

The urban water system can reduce impact on five different “planetary boundaries” (the environmental limits within which humanity can safely operate): freshwater use, biogeochemical flows (nitrogen, phosphorus), climate change, biosphere integrity, and land-system change. According to then report, all but freshwater use is currently under threat of overshoot. 

Advantages for utilities, customers and communities and the environment are detailed in the report. Utilities that go down the circular economy route can expect optimised operational costs, deferred capital investments and resilience to resource shocks.

“I am pleased to see the urban water industry in Australia is actively looking for opportunities with the circular economy to redefine growth, focusing on positive society-wide benefits,” Assistant Minister for Waste Reduction and Environmental Management Trevor Evans said.

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  1. It’s the inherent circularity of water that makes it less relevant than materials in a circular economy. We learned early from nature that water could be purified by evaporating and condensing it. Not so simple a process for getting plastic out of the ocean.