Bright idea for leftovers

BY ANNA FREELAND

A new study by the Institute for Sustainable Futures (ISF) at the University of Technology Sydney (UTS) has revealed the potential for innovative food and organics waste management to generate renewable energy in Australia’s growing cities.

With the population set to reach 40 million by the middle of the century, there is increasing pressure on businesses and households alike to rethink food and organics waste.
“At the moment, a lot of it is just collected in bins and taken off to landfill, sometimes hundreds of kilometres away. It’s ridiculous,” said Andrea Turner, an ISF researcher and lead author of the scoping study.
“According to the NSW Environmental Protection Authority (EPA), households in NSW throw away more than 800,000 tonnes of edible food annually. That’s $10 billion, or $3,800 per household, every year.”

Drawing on international innovations in sustainable waste management, the study looked at a range of options for managing organic waste in the Pyrmont-Ultimo precinct (PUP).
With around 14,000 people per square kilometre and growth expected to continue over the next decade, the Pyrmont-Ultimo corridor is Sydney’s densest urban area.

According to Ms Turner, local interest in organics management spiked after an organics summit held earlier in the year by the ISF and community partners Smart Locale, a collection of businesses advocating for sustainable business practices in the Pyrmont-Ultimo area.
“There’s an awful lot of interest in food and organics waste being turned into a resource and being able to mine the city,” she said.

Ms Turner, who is undertaking a PhD in organics waste management, says there is huge opportunity to reimagine how waste is managed in other dense urban areas and says there needs to be a shift away from traditional reliance on landfill.
“It’s not going to be acceptable in the future. The scale of food waste is phenomenal and has to change,” she said.
“As our cities grow, we need to consider waste much more as a resource that can be treated not just in large scale facilities but also locally to create renewable energy or nutrient rich soil conditioners and composts where it makes sense to do so.”

According to the ISF study, ‘organic waste’ encompasses food, garden and lawn clippings as well as animal and plant based materials and degradable carbon like paper, cardboard and timber. More broadly, the definition extends to other biosolids and sludges produced by wastewater treatment plants.
“That’s why it was so great that both the NSW EPA and Sydney Water supported the study. It helped us to start seeing a bigger picture of organics in the city and reimagining its management.”

On the back of the scoping study, the ISF received funding from the City of Sydney to start a new feasibility project at One Central Park in Ultimo.
The project looks at collecting and treating food waste and other organics onsite, using vacuum systems that literally ‘suck’ food through pipes.
“You could take the separated organics to an offsite treatment process, but we’d like to input it to an onsite anaerobic digester which is a particular type of treatment plant,” Ms Turner said. “These plants can produce renewable energy and nutrient rich soil conditioner for use onsite.”

The ISF vision is to eventually retrofit and trial the vacuum system and anaerobic digester in the basement of the One Central Park building where it would sit alongside the existing water recycling plant run by private utility Flow Systems. The outcomes of the new feasibility project are expected by mid-2018.
“This is a really exciting project which, if the feasibility stacks up, means we would aim to install a demonstration plant in a year or so which would be world leading because it is in the basement of a city building.”

The biggest challenge in switching to a sustainable waste management system, according to Ms Turner, is retrofitting it.
“It really should be done when you design the building. While the Central Park project would be a retrofit, we’re also considering how you would do it at the design stage and how much it would cost.”
Ms Turner says they’ve been collaborating with several businesses from the Smart Locale group on a range of short and long-term solutions, including the Sydney Fish Market (SFM).

The Executive Manager for Corporate Services at SFM Stephen Groom said, “We’re really interested in streamlining the handling of food and organic waste using vacuum systems and generating energy through anaerobic digestion.”
The SFM, which is the largest market of its kind in the Southern Hemisphere, plans to explore possible options when they move to the new Blackwattle Bay site in 2021.
“In addition, we are investigating ways of extracting what is currently treated as organic waste into conversion into a product for its highest and best use,” Mr Groom said.

While excited by the prospects, Ms Turner says it’s not one size fits all.
“The drivers for everyone are so different. I think it requires talking about it to make sure people know how much food is being wasted and that there are different solutions available,” she said. “Over the next three to five years I think things will really start to shift and, hopefully, we will create some real change in Sydney, with the Pyrmont-Ultimo area being a hub of activity and leading the way in Australia and internationally.”