Phototheque VEOLIA - Alexis Duclos

Australia innovates with compost

Posted on 02 August 2016.

Veolia Australia’s Woodlawn site has several recycling techniques. The latest is a mechanical and biological treatment unit that produces compost.

An unusual circular ecosystem, the Woodlawn site has a bioreactor, a livestock farm, a wind turbine - and will soon have a compost production center too.

It looks like a movie set - somewhere between Mad Max and Star Wars. The former open pit mine hosts one of the largest and deepest landfill sites in Australia. 20% of Sydney’s waste is handled there. We’re in New South Wales, in Tarago, 250 km from the megalopolis. Operated by Veolia Australia since 2004, the Woodlawn site offers a truly circular waste treatment ecosystem. It all hinges on a bioreactor that takes the methane produced by rotting waste and turns it into green energy. The heat produced by the reactor is recovered for use in aquaculture and horticulture. The site also has a wind farm operated by Infigen Energy. The wind farm has 23 turbines that harness the energy from the wind on the site to produce 48 MW of electricity.

In addition, there’s an experimental farm which rotates soils to improve meat and wool productivity and reduces soil impoverishment.

Little by little a network of interconnected activities have filled the vacuum left by the old copper, lead and zinc mine.

2016: specific treatment will produce compost

In 2012 Veolia received authorization to increase the volume of waste from 500,000 to 1.1 million tonnes per year. The increase has had several impacts – it has speeded up the production of green energy and the extra waste will now feed the new Mechanical Biologic Treatment (MBT) center, which will be operational this year.

Built for Sydney’s SSROC Council Group (South Sydney Regional Organisation of Councils, which represents almost 1.4 million people), this innovative facility will extract the organic content from the waste stream to produce compost and reduce the volume of waste going to landfill. It required an investment of 60 million dollars. It combines both mechanical and biological processes and has set itself the target of producing 72,000 tonnes of compost every year.

The final stage in the development of the Woodlawn site is the commissioning of a second rail waste transfer unit which is planned for Banksmeadow, south of Sydney. It will be able to handle 400,000 tonnes of mixed waste per year and will add its capacity to that of the Clyde unit which manages almost 500,000 tonnes. MBT will provide further assistance in rehabilitating the site of the former mine.

It is one of the challenges of this geographically atypical site: gradually filling the hole left by past mining operations with stabilized waste and the remediation of other areas thanks to the compost. The contours of the impressive, almost lunar, crater will soften over the years.