Wednesday 26 November 2008

Wasted opportunities

Britain dumps 6.7m tonnes of food a year in landfill sites that emit CO2. But there are cleaner ways to deal with our leftovers
Virginia Matthews
guardian.co.uk, Wednesday November 26 2008 00.01 GMT

Inviting people to assess their likelihood of having liver damage by noting how many booze bottles they recycle - as the Drink Aware Trust is currently doing - might make people drink less. But could encouraging the public to take a fresh look at the congealing carcasses, mouldy macaroni and rancid ratatouilles that make up 20% of the average household's rubbish help us shrink our food waste mountain?
By 2013, when EU plans to enforce stricter waste targets and penalties will be introduced, local authorities will have to show that they are taking radical action to tackle the 6.7m tonnes of food - worth £10bn annually - that currently ends up in landfill sites that emit greenhouse gases.
While local authorities are experimenting with a number of different options for diverting food from the waste stream, it's the potential for extracting usable methane energy, via anaerobic digestion, that currently dominates the debate. This is a waste disposal system that uses micro-organisms to convert organic waste into methane-rich biogas that can replace fossil fuels. The small amount of waste residue from the process can be used as fertiliser.
Then there's the lower-tech option of composting. In Brighton, the council offers heavily subsidised composting bins for home use, but does not offer a collection service. In the London boroughs of Hackney and Haringey, food waste goes first into a small kitchen caddie, which householders empty into a larger bin outdoors. This is collected weekly, mixed with garden clippings, and composted.
Ground to a pulp
In Hereford and Worcester, you get a grant for a waste disposal unit that grinds waste to a pulp, but in most areas of the UK, leftover food still goes direct to landfill, via millions of wheelie bins or bin bags.
Organisations such as Wrap, the not-for-profit Waste & Resources Action Programme, which runs the Love Food, Hate Waste campaign, says it would far rather we all bought less food, or at least cooked up the leftovers and fed them to the dog. But until we do live in an ideal world, the only way to avoid EU fines will be for each of us to learn how to separate, store and handle every last eggshell, teabag and burnt roast potato generated in our kitchens.
Phillip Ward, director for local government services at Wrap, says that although it would be gratifying to think that green-minded citizens up and down the country will flock to home composting, that simply isn't going to happen. "Home composting is an excellent solution, but if you live in a tower block or are elderly, it really isn't an option for you," he says. "Even for those lucky enough to have a garden, there is the problem of rats and other scavengers to contend with, plus you have to be quite selective about what goes on the [compost] pile."
Meat, fish, dairy and anything that has been cooked can smell bad and attract vermin and pests, and should not be added to the compost heap, say gardeners.
At present, Ward says, around a quarter of local authorities are starting to tackle food waste in the run-up to 2013, even if it isn't his preferred option of anaerobic digestion. Of the 100 or so authorities - out of a total closer to 360 - already tackling our leftovers, around 42 operate weekly separated food waste collection services, followed by conversion into methane. Another 60 authorities are offering a mixed collection, though not necessarily storage of food with garden waste. Rather than turning it into methane, they compost and sell it on.
While householders permitted to chuck garden and food waste in together may find it convenient, the odour and even maggots that may result can be an issue.
"While anaerobic digestion is at present the more expensive route, it will become far cheaper once we have more digestion plants in operation and large parts of the country choose this as their preferred option," Ward says.
Wrap has recently trialled separate, weekly food waste collection and digestion via 94,000 UK households, and it believes it has public support. Ward says that initial resistance to transporting unwrapped, possibly smelly food from the kitchen caddy to outside bin has been overcome by the use of biodegradable caddy liners.
Michael Warhurst, senior resources and waste campaigner at Friends of the Earth, is a strong supporter of the anaerobic route. "While composting is fine, the most economical way forward is separate collection and anaerobic digestion, and we hope that more councils will adopt this method as time goes on."
There is another solution, but it is proving controversial. Hereford and Worcester is running a trial of waste disposal units, the electrical under-sink appliances that grind up leftovers, even bones, to a watery sludge that ends up in the sewers. Once the sludge hits the waste water system, it could be recycled into a soil conditioner or converted into methane.
The council is offering a one-off cashback incentive of £80 towards the cost of installing a disposal unit. So far, 1,800 households have taken up the offer.
So what's wrong with flushing food into sewers? A lot, says Severn Trent Water, which warns that the build-up of extra fats, oils and grease in the system will cause blockages.
Ward concedes that for flat-dwellers, the installation of waste disposal units as part of a refurbishment or new build - retrofitting is very expensive - is a possible option. But he warns there may be a cost to households.
"It is fairly possible that water companies would charge people extra for taking away their food sludge, even if they can make money out of it," he says. "When it comes to traditional domestic waste, though, local authorities have no powers to charge you extra money on top of council tax."
Well, not at present anyway.