For years, sewage treatment plants have been the main destination for what is flushed down the toilet.
- Wastewater treatment plants are well positioned to accept organic food waste from households to divert materials from landfill, experts say
- Anaerobic digesters already found in some water treatment plants treat wastewater to create biogas and break down waste
- Water treatment plants would work alongside FOGO services to remove all organic waste from red bins
But the methods used for the treatment of human organic waste could also extend to the treatment of organic food waste destined for landfill.
Within 10 years, the country’s wastewater treatment plants could provide growing communities with a way to reduce their carbon footprint by treating kitchen waste and creating biogas.
At the Wollongong water recycling plant, the infrastructure is already in place.
Sydney Water’s head of strategic planning, Phil Woods, said the vision was for a resource recovery hub or circular economy hub.
“Historically these have been referred to as ‘wastewater treatment plants’, but there is so much resource potential and we are already seeing this with the production of recycled water, renewable energy from biogas and the adding solar panels,” he said.
At the heart of the process are the company’s anaerobic digesters.
These are large mechanical stomachs that collect organic waste and process it, creating biogas and compost, while diverting it from landfill.
Many local government areas in Australia already operate FOGO (Food Organics and Garden Organics) refuse collection services that turn huge amounts of organic waste into nutrient-rich compost.
In doing so, it prevents organic matter from going to landfill where it decomposes and creates greenhouse gases.
Soon, wastewater treatment plants could supplement this service by producing biogas in the process, which can be used to generate electricity.
Woods said the state’s waste and resource recovery strategy aims to eliminate commercial food waste from landfills by 2025 and households by 2030.
“We see a real opportunity to deliver the service to cities by maximizing resource recovery from this waste,” he said.
“How are we going to get from where we are now with this waste that goes into household red bins and get it to a place like this is the challenge we are facing right now, and it will take a lot of collaboration.
“We can’t provide all the solutions, but we have a fantastic facility that will be used to bring even more value to the city.”
He said anaerobic digesters also provide a fertilizer byproduct, similar to FOGO composting.
A zero carbon operation
Sydney Water currently uses its anaerobic digesters to reduce its own carbon emissions.
“It’s an important goal here because recycling water increases our energy demand.”
Beyond that, commercial businesses can be the starting point for bringing in additional food waste.
“It’s a question of what works best for the city. We have 29 sewage treatment plants and Wollongong is one of the biggest,” he said.
“We are looking at all of these to see how we can turn them into resource recovery centers where we can maximize the potential of a plant like this.”