Compost Contamination Guidelines

Contamination of garden and food organics waste is a major problem for recycling organics. Councils, private composters and waste collection companies can all encounter this issue. Every year over 250,000 tonnes of garden and food organics are recovered through collection services provided by council. Currently, collected organics are usually processed to make a range of mulches, composts and organic fertilisers.

Typical contamination

Organic waste can be contaminated by:

• plastic bags
• garden hoses and tools
• bricks and rubble
• plant pots 
• general waste.

Risks and costs

Professional composters screen contaminants, but this adds to the cost. Even after screening, small amounts of contamination can end up in the final product. Too much contamination may cause entire loads to be unusable. Visible contamination in the recycled product reduces the market value and reputation of recycled products.

Advice for councils

Compost Victoria has developed a guide for councils to reduce contamination in kerbside collected services. See download below.

Advice for business and households

Businesses and households can help:

• Don't use plastic bin liners. 
• Train staff in correct recycling habits.
• Ensure that only organics that can be processed by the recycler go into the organics recycling bin.