What happens when our landfills are full? Part 3 – Organics

Landfill biogas
Too much excitement visiting the biogas facility. The well in the top right is capturing the methane emitted from the landfill, and turning it into electricity.

Organic waste accounts for ~60% of our household bins. When organics decompose, they produce methane, which is 25x worse for climate change than our beloved carbon dioxide.

Earlier this year I visited the Eastern Creek Waste Facility (which is full), to see how they capitalise on methane emitted from landfill. The gas is tapped and burned to generate electricity which is sold to the grid. Excess methane is also burned, so that what is emitted is carbon dioxide, rather than something much more potent. Income is generated from the sale of electricity and the creation of both carbon offset certificates and renewable energy certificates. Pretty neat.

Biogas flare: this technology burns the methane emitted from landfill, reducing it down to carbon dioxide, which is 25x less potent as a greenhouse gas.

Why don’t we send all organics to landfill, to capture the methane, create an energy source and therefore income? It seems to make sense. This process, however, still allows ~50% of the methane to escape into the atmosphere. It also doesn’t utilise the nutrients that are locked in organic waste, and it’s what makes our landfills smell so bad.

So what should we be doing with organics?

1.How we separate at the source

In speaking to waste contractors, the best thing we can do is separate our organics at the source. This means a separate food bin at work and at home. There are challenges with extracting organics from landfill, which at this point render it unusable (see point 3).

Only one Council in Sydney currently provides a separate food and organic (FOGO) bin, whereas it’s business as usual across Melbourne, Perth and Adelaide. See if your Council can run a trial or put them in touch with Inner West Council for advice.

You can install separate organics bins in your office – do you have one where you work? Be a champ and get one installed! Make sure to talk to your building management team to get a special organics pick-up.

2. How we design & operate waste rooms

Waste rooms are often just a box on an architectural drawing, but the way that box is designed impacts operations for the rest of the buildings life. It’s essential to ensure there is space for organics separation. A Pulp Master is a great alternative – it chews down the food to be used as fertiliser and keeps it out of landfill.

3. How we process organics

Suez has created a composted product from the organics that are captured in landfill. Where it’s been used on remediation sites, it’s been very successful, and diverts a huge amount of waste from landfill. It’s a better solution, however, coming from landfill there is still a chance of microplastic and heavy metal contamination. This product is currently facing an EPA ban and its future is unknown.

What’s the best way forward?

I believe the best approach is diversion at the source (so it’s clean), with the waste processed in an anaerobic digester, and the methane captured for energy.  The agricultural industry is taking advantage of this technology, capturing animal effluent in big waste lakes (mmm, delicious) where it is broken down by bacteria and used to power their facilities.

We’ve only spoken about organics in the context of food. Anyone willing to tackle sewage?

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