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Assessment of the Sustainability and Economics of the use of Food Waste Disposal Units - WR1307

Project WR1307 forms part of project WR1301, which is an overarching programme of research on food waste disposal (FWD). The programme is investigating the use of FWD units to discharge food waste to sewers, where it could be co-treated with domestic sewage.

The UK produces an estimated 6.7 million tonnes of food waste annually and historically most of this has been collected together with municipal solid waste (MSW) for disposal to landfill. Meeting EU landfill reduction targets has prompted significant changes to the practices for collection, treatment and disposal of MSW and separate collection of food waste with treatment in dedicated composting and/or digestion facilities is an emerging approach.

In aiming to meet landfill targets, the diversion of food waste to sewer for co-treatment with domestic sewage is an approach which needs to be investigated to determine viability and sustainability, taking into consideration that significant investment in the existing infrastructure could be required to increase capacity. Defra needs to investigate the options for food waste disposal in order to balance the needs of sustainable waste management with potential impacts on the environment and the waste water treatment system. This will include assessing the financial and environmental costs and implications of the different options.

The purpose of study WR1307 is to make a direct comparison of the two main collection options; kerbside collection vs maceration and discharge to sewer, each with appropriate subsequent treatment and disposal or re-use of residual solids. This will determine whether or not further investigation into using FWD to discharge food waste to sewer is justified.
The objective of this modelling study is the compare, using readily available data, the whole life environmental emissions and financial costs for two alternative options for the management of domestic food waste:

1) Source-segregated food waste with kerbside collection, dedicated treatment and beneficial re-use in agriculture

2) Maceration in the kitchen using a food waste disposal (FWD) unit, transport in the sewer and co-treatment with domestic sewage.

Within these two broad options, several sub-options are considered, which adopt different methods of food waste or sewage biosoilds treatment.

An assessment of the greenhouse gas emissions and financial costs associated with the use of FWD units, when compared to kerbside collection of segregated kitchen food waste, will assist in identifying and prioritising areas for future investigation.

Time-Scale and Cost
From: 2008

To: 2010

Cost: £3
Contractor / Funded Organisations
WRc plc
Environmental Protection              
Processing techs for treatment /energy recovery              
Residual Wastes Management              
Sustainable Consumption and Production              
Waste collection and handling systems              
Waste Management              
Fields of Study
Waste Management