Work on the next stage of Orange City Council's landfill facility at the Euchareena Road Resource Recovery Centre will start next year.
Following a resolution of Council, the $3.2 million contract was awarded to Synergy Resource Management Pty Ltd.
Orange City Council's Infrastructure Committee Chair, Cr Jack Evans said the pioneering waste management system has been successful since it opened in 2013.
"The purpose-built waste site was designed with a series of giant landfill cells, each as big as two football fields and four metres deep," Cr Evans said. "Rather than simply dumping the waste in a hole, residential landfill waste is compressed into cubic metre bales in Orange and then transported to the site to be stacked in rows."
"It's taken ten years to fill the first two landfill cells, and the third is now being used. The latest contract will see the excavation on of cell number 4. Work is expected to start in the first quarter of next year and we'll then have enough capacity for another five years."
The Euchareena Road facility has government approval to build eight cells on the site, or 40 years of capacity.
Orange City Council's Environmental Sustainability Committee Chair, Cr David Mallard says the design of the waste facility continues to be pioneering.
"As well as the state-of-the-art composting production facility, the Euchareena Road centre is a model for how landfill can be managed," Cr Mallard said. "Baling and stacking the residential landfill waste is a much more efficient use of space. Baling also makes it simpler to transport waste from Orange to the site."
"While most of the food waste has been removed, inevitably there will be some methane produced by the landfill waste, which is a potent greenhouse gas produced by the landfill waste. That's why this contract also includes the job of capping the first two landfill cells with 1.3 metres of clay and topsoil which will be landscaped and planted out with grass and native bushes in due course."
For the first time, a system of gas bio-filters will be installed on top of the capped cells to measure how much methane is produced.
"We're interested to find out how much methane is produced in the underground cell. A pipe will be drilled into the waste which will release gases into a network of smaller surface pipes covered in mulch as a bio-filter," Cr Mallard said.
"That's going to let us safely monitor the amount of gas that's being produced. At some point in the future, that methane might be a resource we can use."
The biofilter acts as an interim treatment system to breakdown the methane produced by the landfill.
When the cells are built, a drainage system is installed to collect liquid waste, or leachate, from the landfill waste. The collected liquid is routinely taken away for processing at the Orange Sewage Treatment Plant.