Organics in Awaba

Waste Management Review speaks with Awaba Green Waste Processing Facility stakeholders about incentivising compost and the impact of high-tech equipment.

Landfill capacity concerns are a common issue for local councils, particularly so for those with steadily growing populations, such as Lake Macquarie City in the NSW Hunter Region.

In 2010, the city’s Awaba Waste Management Facility Landfill was edging towards capacity, landfilling roughly 94,000 tonnes of waste per year.

According to the NSW EPA’s Waste and Resource Recovery Needs Report 2017-21, the state has a known capacity of 31.8 million tonnes of putrescible landfill space per annum. This represents a space gap of 742,000 tonnes, based on the report’s generation figures.

With this mind, Lake Macquarie City Council decided significant infrastructure upgrades were required to prevent future landfill capacity issues and grow resource recovery in the region.

According to a council spokesperson, they found a solution in composting.

Waste Management Review explores the Awaba Green Waste Processing Facility with Lake Macquarie Council, Remondis and ELB Equipment.

In 2010, Lake Macquarie waste audits showed the contents of domestic kerbside garbage bins were roughly 50 per cent compostable organic material, namely food and garden waste.

“These findings presented an opportunity to not only tackle the rising lack of landfill space but also provide a more sustainable waste management solution for the city,” the spokesperson says.

“Timing had never been better to undertake a major resource recovery project that would extend the life of the landfill and save council substantial money in the long term.”

Following the waste audits, council undertook extensive community engagement to develop a new waste strategy. As part of the strategy, council proposed introducing a three-bin kerbside collection system in two phases.

In 2013, Lake Macquarie commenced phase one, introducing fortnightly garden organics collections.

“Introducing a third organics bin helped reduce waste to landfill by 10,700 tonnes at the end of the first year,” the spokesperson says.

Council also partnered with recycling and waste management service provider Remondis to build and operate a 44,000-tonne-per-year composting facility with help from ELB Equipment.

Over 100 contracting firms were engaged to build the facility, which also houses an education centre, where schools and community groups can experience the composting process.

The Awaba Green Waste Processing Facility opened in late July 2018.

Decomposition

According to Gunther Neumann, Remondis Lake Macquarie Organics Resource Recovery Facility Branch Manager, addressing the issue of food waste is the primary function of the Awaba facility.

“Processing green organic waste for mulch or compost is relatively straightforward. However food waste, which presents 40 per cent of Lake Macquarie’s organic material, is more of a challenge,” he says.

As food waste presents several potential risks and health concerns if not handled correctly, Remondis ensures the material is thoroughly pasteurised in a controlled environment before it is composted.

“To address this, we installed five fully automated tunnels at the site which ensure the safety and quality of the output, while also keeping noxious odours to a minimum,” Gunther says.

The facility is a unique hybrid model of in-vessel and mobile aeration flood systems, with a fully automated tunnel composting system capable of pasteurising food waste in two weeks.

Integrating these approaches means the organic material is first subjected to anaerobic digestion before the bioreactor process is switched to composting through forced aeration and material agitation.

Additionally, Awaba features an Australia-first automatic, cashless weighbridge system, giving users access to the facility with the swipe of a card. This incentivise facility use by streamlining the drop-off process, according to the spokesperson.

Hybrid model

To efficiently process the composted material, Remondis engaged long-standing equipment supplier ELB through National Sales Manager Craig Cosgrove.

“Remondis chose to work with ELB due to the company’s after-sales and service credentials,” Gunther says.

He adds that Komptech, which ELB represents in Australia, has a reputation for manufacturing star screens that provide throughput in wet, sticky organics applications.

“With an annual workload of 44,000 tonnes, it’s important for the plant to have high uptimes and consistent throughput,” Gunther says.

ELB was initially asked to supply a Komptech Multistar L3 star screen to separate organics and remove fine particle contaminants following the initial aeration process.

The Multistar L3 star screen provides high throughput across a range of food and organics applications, combined with a patented cleaning system to enhance wet material separation.

According to Craig, the Komptech Multistar separated composted material into three size fractions.

“The large oversize fraction is either returned to the process to provide structure and allow for further breakdowns, or used for daily landfill cover,” he says.

The midsize fraction is used by council on gardens and flowerbeds and sold to the general public as mulch. The fine faction is similarly used as a high-quality nutrient-rich compost for urban amenities, to help facilitate soil health and drought tolerance.

“Council and Remondis sell the compost to landscapers and avocado farmers in the area, and Hunter Valley vineyards,” Craig says.

The performance of the Komptech Multistar L3 caused Gunther to contact ELB again when the facility needed a shredder to process waste after initial decontamination but before pasteurisation.

Craig says Remondis initially tested a few equipment solutions, including a high-speed grinder.

“The high-speed grinder turned any residual plastic contaminants into confetti, making it impossible to separate out,” Craig says.

“High-speed grinders are also known to have a low resistance to contraries, and as a result, high downtime.”

After consulting with Craig, Remondis trialled a Crambo Direct dual-shaft shredder.

The shredder has two slow-running drums, with shredding tools that minimise fine particle noise and dust emissions while resisting contraries.

“The Crambo keeps our output high and consistent,” Gunther says.

“We know we can rely on ELB and Komptech to provide excellent equipment.”

Gunther adds that working with ELB on the Awaba project highlighted the importance of engaging with companies that understand the composting process and provide high-quality equipment.

“We could have the most high-tech automated composting system in Australia, but without reliable and efficient equipment to perform the secondary separation job, it wouldn’t amount to much,” he says.

Craig says ELB is proud to have their equipment employed at the Lake Macquarie facility.

“ELB is an industry partner, first and foremost, and we’re thrilled to have the opportunity to work with Remondis at the Awaba facility once again,” he says.

“After all, it is one of the most advanced of its kind in Australia.”

The future

According to Craig, the Awaba facility provides an example for other councils hoping to follow in Lake Macquarie’s composting footsteps.

“With more impetus coming from government to recycle, the Awaba facility welcomes a steady stream of visitors from other local councils to assist and educate them on set up cost, approvals and processes,” he says.

“Thanks to the technology employed at the Awaba facility, Lake Macquarie can reduce its landfill rate by as much as 30 per cent.”

While still in its early stages, Lake Macquarie’s spokesperson says Awaba’s impact has been significant.

“Council collected and processed 38,000 tonnes of food and organics material in the facilities first 12 months, with an annual average contamination rate of just over one per cent,” the spokesperson says.

“This is a 17,000-tonne, 80 per cent increase in diversion of organics over the previous year.”

In the same period, council reduced the amount of landfilled waste from its domestic waste collection service by 22,380 tonnes, highlighting the community’s engagement with the facility and wider FOGO collection system.

“Success will be measured over time by tonnages of organic waste received and processed, participation in the kerbside green waste service, low rates of contamination, balanced operating costs and numbers of community and school tours to the on-site education centre,” the spokesperson says.

“While strong rates of participation and low rates of contamination are pleasing, they are not yet perfect, and council will continue to work closely with Remondis and the community of Lake Macquarie to support ongoing improvements in services, and the overall efficiency of the facility.”

Gunther adds that in just over a year of operations, the facility has shifted diversion rates from 41 per cent to 64 per cent. If rates continue to climb, he says the facility will save council an estimated $4 million in waste management costs over 10 years.

“Remondis applauds forward-thinking local government organisations, such as Lake Macquarie City Council, for their dedication to building the vital recycling infrastructure that will create job opportunities, strengthen the Australian economy and reduce our environmental footprint,” he says.

“It’s important to Australia and the waste and recycling industry that more councils adopt source-separated food waste recycling.”

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