Recycling a City’s Kitchen Scraps

I stand in the open maw of a huge tunnel that stretches into darkness, the floor grubby and stained, and the damp air filled with the smell of decay. I think of all the banana peels, chicken bones and everything else that spent time in here, slowly transforming. The huge vault is part of a much larger facility, apparently one of the most advanced of its kind. The scale of the operation is incredible, and all for a substance that I hadn’t realised the importance of.

It all started when I’d asked my friend who I was staying with where her compost bin was so I could throw out my food scraps. She’d pointed to a strange-looking container lined with some kind of green plastic bag. It’s not plastic, she said, it’s compostable, and she went on to explain how you tie it up when it’s full and put it in the bright green-lidded kerbside wheelie bin along with your organic garden waste. Being from WA I’d never heard of this.

Pedalling on through NSW I encountered this phenomenon in a couple more towns, though most places hadn’t heard of it — their kitchen scraps either went into their own vege garden or into landfill. I was intrigued and wanted to find out what happened to these compostable bags of organic waste.

Arriving at the Grafton Regional Landfill in northern NSW, I pull my bike up outside a single-storey office building near the gatehouse. A man named Richard, the Waste and Sustainability Officer for the Clarence Valley Council, greets me, followed by his colleague Chris, and we decide to dive straight into the tour.

We walk into the grounds of the landfill, past the recycling station, and past the turnoff to the main landfill pit. There’s a small enclosure to our right piled high with tree branches, leaves, and other plant debris — a public drop-off point for garden waste.

At last we reach a large building, the front a huge open shed and the back section an enclosed building. On the concrete floor of the shed sits an excavator surrounded by piles of organic waste; a man in a high vis vest walks amongst the piles with a bucket in one hand and a metal claw in the other, sifting through the waste.

This is their FOGO facility — Food Organics and Garden Organics. For many years Australian landfills have been receiving just Garden Organics (the GO in FOGO), but the inclusion of food organics with this is a relatively new innovation that is spreading across the country, with Grafton being an early mover.

There’s a man driving the excavator, though he shuts it down when he sees us, climbs out and comes over to greet us, introducing himself as Phil. He tells us that they receive about six truckloads of FOGO a day here, collected from kerbside wheelie bins across the Clarence Valley region, a population of over 50,000 people. They’re currently getting about 110 tonnes per week, but it can reach up to 200 tonne per week in summer and be as low as 90 tonne per week in winter.

Their worker Josh is sorting through the piles and removing any obvious contamination, such as non-compostable plastic bags, which get put into a skip bin off to the side. I weave my way through the FOGO and peer into the skip bin. Inside is a smelly mass of mostly plastic rubbish. Phil tells me they fill a skip bin a week with contamination.

Later we watch as a large garbage truck pulls in, reverses up to the shed, tilts up its barrel-like body and dumps a load of FOGO onto the concrete floor. They tell me the trucks have cameras mounted so that when they’re picking up your wheelie bin off your kerbside the driver can see the contents of the bin before it’s tipped into the body of the truck. If there’s any issue the driver pushes a button marking it as either ‘contaminated’, ‘overweight’, or an ‘illegal bin’, and this goes into the system along with the house number. They may reject the bin if it’s too contaminated, a warning sticker is placed on the bin, and if it happens repeatedly they may stop collecting that bin altogether.

Thanks to this, along with the assorted waste education programs they run, their contamination rates have dropped from about 5% to roughly 0.5%.

In the corner of the open shed is a large machine: their high speed shredder. When we arrived, Phil had been picking up the FOGO with the excavator and dropping it into the shredder, where it gets smashed into small pieces by carbide-tipped claws. Phil shows me one of the claws, and explains that the carbide tips are incredibly hard but brittle. If they hit against a piece of contaminating metal, for example, they’ll shatter, costing thousands of dollars to replace.

The shredded FOGO gets spat out through a hole in the wall into the enclosed part of the building. We walk through into the large chamber, where the shredded FOGO is piled up like mulch against a side wall.

In front of us are what look like three giant oven doors in the back wall of the chamber, one of them open revealing a long, dark tunnel, extending into darkness. The pasteurisation tunnels, they tell me. The open one is empty, and walking into its dark mouth we can see that it’s about forty metres long.

Phil explains how once the shredded FOGO is packed into the tunnel and the doors closed, it all heats up due to the natural process of biological decay. Water sprinklers in the roof keep it all moist, and he lifts up a piece of the floor revealing one of the troughs underneath that carry the water away, to later be re-circulated. Air comes up through vents underneath, providing oxygen.

Temperature probes measure how hot it’s getting and an automated control system uses a series of fans and vents to adjust airflow and regulate the temperature — 55 degrees for the first week, then 60 degrees for three days. Pasteurisation takes two weeks, accelerating the composting process while also destroying pests and diseases and neutralising plant seeds, but allowing useful bacteria to survive. Phil says he can control the whole system via his smartphone.

He opens a hatch in the door of each of the two closed tunnels, letting me peer inside. It’s dark and steamy, and full of composting FOGO right up to the doorway. I’m delighted to discover several mushrooms growing on it, alongside a candy bar wrapper that somehow made it through.

We head out through a side door and along the outside of the building, soon reaching a set of stairs that take us to the rooftop. Standing above where the empty tunnel would be, Phil shows me one of the temperature probes on a long metal rod, and a hole in the roof through which it’s lowered deep into the FOGO in the tunnel below.

Behind the building is the air filter bed, a square compound covered in some sort of organic mulch, covering the outlets for the air vents from the pasteurisation tunnels. The mulch apparently helps to absorb any bad odours. It occurs to me that I haven’t noticed any bad smells after leaving the open shed where the FOGO was first dumped.

Beyond are piles and piles of what must be composting FOGO, heaped into huge rows, and we gather at the rooftop railing to look out over them. They seem grouped into different shades of brown, suggesting different consistencies, and many are flecked with white. Several piles alongside the building are covered in the white bits, which look like shredded plastic bags.

Phil explaining how, after being taken out of the pasteurisation tunnels, the compost goes through these stages of piles. Every two weeks each pile is turned over into the place of the next pile, to mix and aerate it. After a tunnel’s worth of compost has been through several piles, its put through the ‘screener’, a machine which separates out the ‘fines’ from the ‘oversize’; that is, the fine soil-like particles from the oversized pieces. All the oversize goes into a new pile, which gets further turned every fortnight for three more times, allowing it to further break down and produce more fine soil. It gets screened again, and any oversized pieces coming out of this screening are called ‘double oversize’.

This explains the flecks of white and the different consistencies we can see in the different piles. The contaminating bits of plastic don’t break down, and so each screening is separating out and effectively concentrating this plastic contamination, such that the brown oversize piles are flecked with white and the double oversize piles appear almost grey with it.

Descending from the rooftop and walking amongst the piles, we eventually reach a strange vehicle sitting alone at the end. This is the special screening machine, which has recently received a fresh coat of paint. Phil points out how the compost is passed through a rotating cage that’s perforated with small holes — the size of the holes determine the size of the particles that are allowed through. It then deposits the fine soil in one pile and the oversize in another. Phil points out where large suction fans are fitted on top of the chute that ejects the oversize, explaining how these suck off some of the lighter bits of plastic bags. They don’t catch all the contamination this way, but it helps to reduce it.

Nearby are the piles of fines, and I take a photo of Phil scooping up a handful — the ‘money shot’, we joke. This dark soil is their end product, which they sell to farms, parks and gardens throughout the region. It’s amazing to think that all those kitchen scraps collected from tens of thousands of homes around the region — a huge logistical exercise — has been turned into this rich compost, ready to be used as a natural fertiliser to help grow more food.

I see a fleck of white, and bend down to pick it up. An apple sticker — one of those small plastic labels showing the fruit’s trademark. When I show it to Phil, he says they’re one of the few bits of contamination that still gets through. But they’re inert and harmless. The Australian Standards require contamination levels in commercially-sold compost below 0.05%, and here it’s less than 0.02%. Nonetheless, I make a mental note to myself to always peel off the fruit labels from now on.

It takes about twelve weeks from when the FOGO first enters the tunnels to when it receives its first screening. They have to process all the FOGO within 24 hours of when it arrives on site, and they fill a tunnel every week in summer.

I ask what happens with the double oversize, and he says that after giving it as much chance to break down as possible, the remainder goes to landfill. About 95% of the original FOGO they receive is turned into compost, and about 5% ends up in landfill.

I’d been told before coming here that Grafton’s FOGO facility was one of the best. When I ask how other locations are different, Phil tells me that some don’t have tunnels, but otherwise they’re all pretty similar. ‘It’s all the same natural process, and we’re just helping it to happen as efficiently as possible’.

We slowly amble back to where we started, say farewell to Phil, then return to the office. I sit to eat my lunch in the office kitchen, and soon Ken, the Waste Coordinator for the Clarence Valley Council comes in to join me.

He tells me that more and more councils are switching to FOGO, for a number of reasons, not least to save money, as landfills in NSW currently charge $83 per tonne to dump waste. According to the National Waste Report, 87% of Australia’s household food waste went to landfill in 2016-17, with the number of councils now offering FOGO recycling at 16% and growing.

It also helps the climate, as FOGO produces methane, a potent greenhouse gas, if left to decompose anaerobically (without oxygen) in landfills. Food waste in Australian landfills produces as much greenhouse gas emissions as Australia’s steel and iron ore industries combined.

This FOGO facility was one of the earliest, introduced as far back as 2012. Before that they were just collecting co-mingled recycling in the yellow-lidded kerbside bins, which diverted 41% of waste from landfill. After FOGO was introduced, this went up to 63%.

Key to this was changing the red-lidded bins (landfill) to fortnightly, and the bright green-lidded bins (FOGO) to weekly. This pushes people to have to use their FOGO bin and co-mingled recycling bin more. If a council that’s introducing FOGO doesn’t do this, then it won’t work, he says, as people won’t have an incentive to change their behaviour.

They grumble at first, and there are lots of complaints and questions about the new system. But then they get used to it and the complaints stop. There are a lot of tourist towns in the region though, and it’s challenging having so many holiday-goers who don’t understand what to do.

After what’s been a fascinating dive into the world of FOGO, I finally say goodbye to the waste team and set off again on my bike.

Two days later I arrive at the coastal town of Yamba, where I’ll be house-sitting for a week for an old friend Anna. After settling in to the house, I make myself lunch, but when I go to dispose of my kitchen scraps I can’t find the kitchen caddy, despite searching in all the cupboards. I realise that, with Anna only moving here recently from WA, she likely isn’t aware of the different system here.

Over the next few days I travel to the local council office to get a kitchen caddy, and then pick up some of the green compostable bags to line it with from a vending machine outside the local supermarket.

As I set it up on Anna’s kitchen bench, I find myself wondering if she’ll mind me imposing this on her. The label on the front says they take fruit and vegetables; meat, fish and poultry (even bones); dairy products; tea leaves, bags and coffee grinds; and grains, cereals and bread. Just no plastic bags.

Something tells me she’ll love it.

Huge thanks to Richard, Chris, Phil and Ken for taking the time to show me around and explain their operations.

Thanks for following my journey! Can you donate to help keep me pedalling forwards?