With less food waste ending up as landfill, pressure on commercial operations to do the right thing can only increase, so it’s worth considering some of the available options.
20 May 2010
There’s more to a grapefruit than meets the eye. And, equally, more to running a kitchen than making sure the plates arrive on the tables at the right time, with a flourish of garnish. Take food waste, for example. Kitchen managers have long been experts at allowing for variations in footfall and unpredictable weather conditions. But however carefully you manage stock, wastage will always be a fact of catering. So what do you do with it?
Until recently, most food waste was sent to landfill, and no one kept a record of how much was being produced. Once deposited at the landfill, food waste decomposes to form methane, one of the most dangerous greenhouse gases, with the resulting liquids occasionally leaching out to pollute local river courses.
These days, less and less food waste is going to landfill; over half of UK local authorities now collect from households while commercial operations are looking for ways to reduce costs and maximise environmental performance. With government discussing a total ban on food waste to landfill, pressure to do the right thing can only increase, so it’s worth considering the options now.
1. Environmental audit
The first thing to do is work out how much food waste you produce. If your organisation is taking part in an environmental audit, it is important to include food waste in the process. Alternatively, multiply the number of covers by 0.3 for a rough figure. If you feed 100 people a day, for example, you can expect to produce around 30kgs of food waste. If your business regularly disposes of significantly higher levels of waste, then it’s time to look at your ordering regime and adjust accordingly.
2. Commercial collection
Food waste separated for recycling comes under the Animal By-Product Regulations (ABPR), which ensure that where it is treated commercially to produce compost or digestate, it is processed in a fully enclosed system and reaches temperatures guaranteed to kill any residual bugs. Commercial collectors will have an arrangement to take food waste to large-scale, ABPR compliant sites. These include in-vessel composting systems and anaerobic digestion facilities that also extract gas from the process. Few companies currently offer a separate food waste service, although supply is increasing with demand. London-based businesses are far better served than organisations outside the capital.
Companies often choose this method because it ties in with their existing system and can be dealt with through one contract. However, it is unlikely to result in reduced waste management costs and will require additional space for the storage of food waste awaiting collection and increased vehicle movements at collection time.
3. Composting on site
Small-scale, on-site composting is exempt from ABPR but the material must be collected, processed and then disposed of on the site where it was produced, so only organisations with sufficient grounds to install a composting machine and spread the resulting compost are able to use this system.
Access routes to the machine need to be considered, in addition to storage for food waste prior to its addition to the machine. Staff will require training, and it helps if one member of staff agrees to take responsibility for monitoring input and compost quality.
Effective composting relies on a combination of nitrogen-rich material (eg, food waste) and carbon elements like cardboard or sawdust. Where food waste is the main input, carbon rich material needs to be sourced and added to the mix; this may require the purchase of additional material and vehicle deliveries to the site.
4. Decomposition system
Food waste decomposition has been a feature of the luxury hotel market in the US for some time but has just begun to make a name for itself on the UK market. Unlike a composter, which produces a solid output, it uses enzymes to digest leftover food, resulting in just a trickle of grey water to drain.
The machine is situated in or near the kitchen, where it can be accessed as waste is produced. As the hatch to the chamber is opened for the addition of each load of vegetable peelings or leftovers, the enzymes, which sit on a bed of wood chip, are activated to ‘eat’ the waste.
With material added as required, there is no need for storage bins or collections, and no energy used while the machine is dormant.
5. Fareshare
If your organisation deals with significant levels of useable food waste, you might want to consider donating it to a local Fareshare project.
Established in 1994 as a project within the homelessness charity, Crisis, Fareshare aims to help vulnerable groups, whether they are homeless, elderly, children, or other groups in food poverty within communities. Donated food is distributed free of charge to organisations feeding vulnerable groups.
CONSIDERATIONS
• What are you trying to achieve by treating food waste separately? Cost savings? A ‘closed loop’ system? Reduction in storage of food waste?
• Is any of your food still edible?
• How do your volumes of food waste relate to the size of collection bin on offer – will you be paying for the collection of a large bin that is only half full?
• Do you have flower beds or other grounds that would benefit from on-site compost?
• Do you have external space for a composting machine?
• Do you have buy-in from staff?
• Do you have space in, or near your kitchen for extra equipment?
Carolyn Cross is an independent communications consultant and journalist specialising in the environmental sector
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