What South Australia's organics sector is actually worth
Prepared by Rawtec in partnership with RMCG, BDO EconSearch, Lifecycles and Carbon Clarity, for Green Industries SA. Summary of the 2020 baseline analysis.
Summary published
Composting is usually argued for on environmental grounds. This analysis put an economic number on it, and then a second number on what happens to the farms that use the product.
The sector handles 1.35 million tonnes of organic material a year and contributes $189 million to gross state product directly. The downstream lift in farm productivity is worth almost the same again, $190 million.
The report notes the sector is similar in size to South Australia’s forestry, fishing or aquaculture industries.
Combined contribution to gross state product
Full-time equivalent jobs, direct and downstream
CO2 equivalent avoided each year
Of agricultural land improved
What the modelling showed
Composting beats landfill on every measure they modelled
Per tonne, composting generates $367 of gross state product against $33 for landfill, a difference of $334. It supports 9.6 full-time equivalent jobs per 10,000 tonnes against 3.6 for landfill. And it avoids 641 kg of CO2 equivalent per tonne.
Where the material goes now
Composters and mulchers take 607,600 tonnes a year and produce 367,400 tonnes of product. Meat rendering takes 244,000 tonnes and produces 97,600, mostly tallow and meat meal. Other processors take 274,100 tonnes. And 228,400 tonnes of unrecovered organics still goes to landfill, which is 17% of the total.
The soil side of the ledger
123,400 dry tonnes of recycled organics go onto farms each year, adding 34,700 tonnes of soil organic carbon and improving 21,500 hectares. That is where the $190 million of downstream productivity comes from.
Water and emissions
2,300 megalitres of water saved a year, equivalent to 18,000 households. 239 kilotonnes of CO2 equivalent avoided, equivalent to 90,000 households. Landfill, by contrast, emits 507 kg of CO2 equivalent per tonne of organics buried.
The constraint is feedstock, not demand
The report’s finding is that South Australia already has an advanced composting industry with demand for its products. What limits the sector is the supply of material coming in. Kerbside food waste diversion sits at 11% and commercial food waste at 12%.
What a 2030 high-diversion scenario adds
Lifting kerbside diversion to 75% and commercial food waste to 60% would take overall diversion from 83% to 91%, divert another 112,000 tonnes, add $37 million of gross state product and 68 jobs, save a further 64 kilotonnes of CO2 equivalent, and improve another 4,000 hectares of farmland.
Four newer technologies, modelled but not judged
Dry and wet anaerobic digestion at 50,000 tonnes a year each, generating $6.8 million and $7.9 million of gross state product. Heat treatment at 22,000 tonnes producing poultry feed and liquid fertiliser, $5.6 million. Black soldier fly at 1,800 tonnes producing 400 tonnes of insect protein, $1 million, and the highest value per tonne at $653.
What the analysis does not tell you
The report says plainly that whether the four newer technologies stack up commercially was not assessed. They are proven elsewhere but not operating at commercial scale in South Australia.
Heat treatment’s greenhouse benefit runs from 207 to 701 kg of CO2 equivalent per tonne depending on what animal feed it displaces. Feed blending is complex and dynamic, and the study says it cannot be certain of market-wide effects.
Organics managed on site, and informal processes, are outside the analysis. The 1.35 million tonnes is what moves through the formal sector.
Only composts and mulches made to Australian Standard AS4454-2012 and the NASAA organic standard were included in the soil health modelling.
Related reports
The statewide recycling counts these figures sit inside.
The summary covers the material flow, lifecycle, soil health and economic modelling. Green Industries SA gives no warranty as to accuracy or suitability for a particular purpose.
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