Food Waste Disposal Units – Is the Jury Still Out?

Food waste disposers (FWDs) are considered valid tools for separating kitchen waste at source and diverting it for recovery via the use of existing utilities and drainage infrastructure. However their uptake varies considerably across the world – while the US, New Zealand and Australia have high rates of installation, European countries have largely shunned them.

There is limited research on the potential impacts of FWDs, but the general scientific consensus appears to suggest that they don’t harm sewer systems or wastewater treatment plants, can provide an effective source of biogas (and subsequent energy generation), and contribute towards lower solid waste disposal costs.

That said, there is still resistance to utilitising this particular method of anaerobic co-digestion. There are a multitude of area-specific characteristics that exist across different cities and regions such as water resources, household practices, condition of the sewerage system and wastewater treatment processes, and these can all affect the viability of FWDs as a comprehensive waste management option.

At a higher level, regulatory barriers may come into play. In the UK for instance, sewage sludge and food waste digestion operations sit under different legislative and management regimes. While FWDs might result in cost savings for waste collection authorities, they are often seen as an additional burden for water industry operators. Elsewhere, other countries have placed restrictions on the use of FWDs with some actively discouraging their use in households due to concerns over competition laws and capacity.

Given these factors, it may be hard to establish for a given region whether FWDs should become the solution of choice for household food waste. This debate will attempt to evaluate what practical considerations are needed to make an informed judgement.

Questions

1. Considering the carbon impacts of household food waste collection logistics, is there is a pressing case for these disposal units to be more widely adopted?
2. Certain countries or regions argue there is a need for further evaluation – what top-level considerations need to be taken into account here?
3. Where could deeper research on food waste disposers be beneficial?
4. What type of cost-benefit and lifecycle analysis is needed to support this research?
5. Are there opportunities for knowledge transfer here, where lessons can be learnt from those areas that have established these disposal units as the optimum solution?
6. There is still widespread uncertainty, certainly within Europe, regarding the impacts of these disposal units on wastewater treatment facilities. In the UK for instance, there is a fear that responsibility for food waste management could shift from one industry (waste) to another (water) – these are complex issues, how might we begin to address them?
7. Could there be opportunities for the water industry to benefit, particularly from the energy potential of co-treating food waste?
8. What enabling factors need to be in place so that these disposers become the most sustainable option for dealing with household food waste?