By Jacqueline Ong
Despite the country’s dependence on landfill, federal and state waste strategies have increasingly moved towards greater resource recovery and waste avoidance,while governments are noticeably more open to alternative waste treatment facilities. Do these factors, plus fast depleting airspace (particularly across urban landfills) mark the sector’s imminent demise?
Australian Landfill Owners Association spokesperson Max Spedding, who began his career in the sector more than two decades ago, does not think so.
He shares his views on how far the sector has come and what it should expect moving forward.
“We constantly hear predictions that landfills will be phased out over the next 25 years. Having commenced in the industry 25 years ago, predictions of this nature seem little more than pipe dreams,” Spedding said. “Yes, there will be more processing in the future, especially of pre-sorted waste streams but waste volume growth and the nature of mixed waste will see a need for landfills in the full suite of facilities serving future markets.
“For example, waste to energy creates ash that requires landfill; biological treatment has a residual that requires landfill; waste sorting – even after the recovery of refuse derived fuel – has a fraction that will end up at landfill; in emergencies landfill are critical to clear up, etcetera. So landfills will be with us well into the future.”
In fact, Spedding expects landfill volumes to remain steady. But he said what might change would be the waste mix, with less construction and demolition waste and less organic content in the domestic stream.
He also foresees a continued improvement, in general terms, of the overall standard of operation, as older sites that date back to the 1980s shut down and rural dumps are replaced with transfer facilities trucking waste to regional landfills.
New landfills have already started to embrace new technology extensively over the last decade.
“We now have composite liners, leachate collection, recycling and treatment, alternate daily cover, landfill gas collection and energy use, improved odour management, phytocapping, onsite recycling and composting and increased attention to landscaping and site appearance,” Spedding said.
One interesting new idea that emerged in the latter half of the last decade is the high efficiency sediment (HES ) flowthrough basin, an alternative to the traditional batch treatment sediment basin, which landfill operators are legally required to install to capture and treat water during rainfall events.
Traditional basins may have worked for years. However, the downside is that operators are required to treat and dewater run-off manually – a timeconsuming and costly operation. The basins also take up a lot of space, which many landfill sites simply do not have. When operated correctly, water captured in a traditional batch type sediment basin should be treated and dewatered within five days of a rainfall event.
Two companies, Turbid and O2, have come up with a simpler and more costeffective system, which they say has a treatment efficiency of about 90% and takes up between a quarter to half the size of a traditional basin.
Each HES basin has an intelligent flocculating operational device.