NSW FOGO bin performance: kerbside green lid bin audit analysis
Prepared for the NSW Department of Planning, Industry and Environment. Analysis of 12,239 bins across 26 councils, audited between 2011 and 2019.
Summary published
This is the 2020 update to Rawtec’s 2018 analysis of NSW food and garden organics bins, with a larger dataset: 34 audits across 26 councils instead of 26 audits across 20.
Food waste diversion improved over the two years. Contamination fell. The underlying pattern did not change.
Of available food and garden organics diverted
Of available food waste diverted, up from 38%
Average contamination, down from 2.6%
Of available garden organics diverted, unchanged
What changed since 2018
Food diversion improved, contamination fell
Food waste efficiency rose from 38% to 44% and the amount of food reaching the FOGO bin went from 1.20 to 1.45 kg per household per week. Average contamination fell from 2.6% to 2.2%. Garden organics diversion stayed at 98%.
Overall capture is 85% of what is available
Across the audited councils, 12.3 of the 14.4 kg per household per week of food and garden organics generated was diverted, or 85%. Garden organics accounted for 10.81 kg of that.
The same service configurations win
A small 120 or 140 litre residual bin collected fortnightly alongside a weekly FOGO bin reached 57% food diversion, up from 54% in 2018. A user-selected configuration reached 47%, a large fortnightly bin 38%, a small weekly bin 28%, and a large weekly bin 14%. The report puts it plainly: the less access households have to landfill disposal, the better the result.
Maturity still matters
Services older than a year averaged 46% food efficiency, against 34% under a year and 28% in trial.
Most bins are clean, a few are not
Between 68% and 92% of bins in the five councils with matched household data contained no contamination at all. Council contamination rates ranged from 0.04% to 17.83%, with the middle half between 0.7% and 3.3%. The user-selected configuration was the outlier at 5.4% against 1.5% to 1.7% for the others.
Frequency and weight tell different stories
The most frequently found contaminants were plastic, other organics such as leather, rubber and oils, containerised food, metals, then miscellaneous. By weight the order changes: miscellaneous items such as bagged material and bulky goods come first, then earth-based material, then plastic. Chasing the most common contaminant and chasing the heaviest are not the same job.
Food participation still varies enormously between councils
Across the five councils with bin-by-bin data, the share of FOGO bins containing no food at all ran from 27% to 70%, and average food per bin from 0.67 kg to 7.2 kg.
What the report concluded
NSW weekly FOGO services are performing well at diverting organics. The remaining opportunity is education focused specifically on food waste.
Food waste diversion is more likely to increase by increasing the number of participating households than by making existing participants more efficient.
Because contamination sits in a minority of bins, bin tagging aimed at those households is likely to beat broad education campaigns.
Garden organics generation ranged from 1.06 to 23.67 kg per household per week. The report attributes that spread to rainfall, vegetation, block size, population density and the time of year the audit ran, not to service quality.
Seven things to fix in future audits
The 2020 report repeats and extends the audit quality recommendations from 2018.
Keep emphasising randomised sampling. Some audits in the dataset were not randomised, which limits what can be read from them.
Give clear guidance on stratified sampling for multi-unit dwellings. Several councils sampled them inadequately.
Emphasise representative sample sizes. The guideline minimum is 220 bins and several audits came in under it.
Put standard contamination definitions in the audit guidelines. Councils were using different ones, so the rates were not directly comparable.
Support auditor training on waste generation rate calculations. Rawtec found errors in them.
Record instances of gross contamination, above 20%, separately, so the effect of including or excluding them can be tested.
Require the key audit information in the report and retain the raw data. Missing metadata made some audits unusable.
Related reports
The rest of the kerbside audit series.
The full report includes all five bin-by-bin council analyses and the complete contamination breakdown.
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