Should composting begin at home?

An estimated 12 million tonnes of biodegradable household garden and food waste is collected in the UK every year and the vast majority of it still goes to landfill.

Despite WRAP’s recently announced business plan for 2006-8, which gives a higher priority to organic waste with a strong focus on food waste reduction and composting, household treatment of garden and food waste is still not playing a large-scale strategic role in UK waste management plans.

The waste management principles of sustainability, self-sufficiency, dealing with waste at source (principle of proximity) and the cost of disposal being borne by the waste owner (principle of polluter pays) apply to individuals – not just counties, regions and nations.

However an anomaly in the mass balance formula used to calculate the quantity of biodegradable waste diverted from landfill is encouraging a growing number of local authorities to establish schemes for segregated kerbside collection and centralised treatment.

Because of this, LAs are not following national policies on minimising the amount collected by promoting household treatments, such as the use of home composters and food waste digesters (FWDs).

Feedback from LAs also indicates other barriers to introducing more household treatment schemes – these include a lack of specific targets and economic instruments to drive waste prevention, the existing best value indicators and the focus on statutory performance standards.

In order to assess the contribution which the household treatment of food waste could make in diverting biodegradable waste from landfill, I undertook a review in which a ‘reference’ FWD system was compared with the centralised approach of segregated kerbside collection followed by in-vessel composting and disposal. The reference FWD system was chosen on the basis of the availability of information in the public domain.

Home economics

This preliminary assessment was carried out in the context of the relevant European Union directives and the resultant national waste management strategy objectives and decision-making principles. It indicated that detailed risk assessments are likely to favour the household treatment option for most situations.

It showed that the household treatment costs are better than half the average for segregated collection and centralised treatment, where the cost advantages are greatest for authorities serving rural areas, and improve further with rising oil prices.

It also showed that FWDs can:

• facilitate public acceptance of less frequent collections, helping to reduce vehicle operating costs, accidents and pollution
• result in cleaner bins and waste for householders, encouraging recycling of other domestic waste streams
• reduce street clutter and accidents caused by segregated collection receptacles
• limit the growth of food waste.

Based upon 10% of UK households using FWDs – the current situation for home composters – half a million tonnes of food waste could be diverted from landfill and not have to be collected. In addition, between 10 and 25 centralised treatment facilities need not be constructed, with potential cost savings in excess of £20 million a year.

For the household treatment of food waste to become an established part of an integrated waste management strategy, certain steps need to be taken.

Firstly, WRAP and DEFRA need to resolve the anomaly with the landfill allowance mass balance formula and complete their current trials of FWDs.

Secondly, national advice programmes for waste collection, disposal and planning authorities need to contain information on household treatments, not just centralised approaches.

Thirdly, responsible authorities need to include the option of household treatment when determining their waste management strategies.

Finally, a range of specific targets and economic instruments need to be developed to drive waste prevention and the household treatment of food waste.

• For a copy of Dr Alan Knipe’s report The Management of Household Food Waste, email alanknipe@tiscali.co.uk