As anyone who has travelled extensively in the United States will know, domestic waste disposals are an everyday feature of many US households. According to one of the market leaders, InSinkErator, market penetration levels across the Atlantic are as high as 49 percent – equalling dishwashers – while as many as 90 percent of new homes have a waste disposal unit pre-installed.

Unlike other household appliances, the benefits of using waste disposals within the broader environmental context are not well explained and are only just beginning to come to the fore now that local authorities are moving to less frequent bin collections and to a plethora of different schemes involving segregation of household waste. This article examines the (often competing) forces at work as the waste disposal sector seeks to bring about a change of mindset.

Extensive, original research conducted in the UK by The Strategy Works among manufacturers, distributors and local authorities suggests that the potential for the food waste digester (FWD) to play a part in the safe and effective disposal of our estimated 6.7m tonnes of food waste is not well understood.

Yet while there are persuasive environmental arguments for this long-established and easy to use kitchen device to become as much a part of householders’ lives in the UK as it is in the US, fuzzy thinking, insufficient hard data, lack of consumer awareness and, above all, the lack of a “helicopter view” (or a general outline) from Government, has thus far consigned the growing problem of food waste disposal not to the kitchen sink – where some experts believe it should be re-routed – but to the general refuse bin.

Currently, most of our organic kitchen waste – up to 75 percent of it moisture – ends up in overflowing landfill. For those local authorities with no facilities to either collect food separately, let alone divert it into composting schemes, food waste is not only expensive to transport, but is a significant source of methane. So what are the arguments for and against diverting food waste to our sewers? Not surprisingly, InSinkErator is a staunch advocate of FWDs and is lobbying hard at local and national government level for its devices to become as commonplace as dishwashers. It claims that when fitted under a domestic kitchen sink, FWDs can reduce household food waste by up to 25 percent.

At a time when environmental concerns are moving higher up both the political and consumer agenda though, the firm’s perspective goes beyond that of sheer commercial advantage, as sales and marketing director Ashley Munden explains. “Reducing landfill is of crucial importance to local authorities over the next 15 years. Failure to meet EU targets will result in fines which could ultimately be met by an increase in taxes,” he says, unequivocally.

“Recycling is not optional, it is essential if we are to create a sustainable environment for our children. The food waste disposer can work in harmony with other recycling methods, such as composting, to meet these strict targets.” So far, so good, but what are the scientific facts?

Dr Tim Evans is an independent consultant and one of the country’s leading scientists specialising in alternative ways of treating food waste. Last June, Evans produced a study of FWDs for Herefordshire and Worcestershire County Council (H&W) which concluded that they are “a cost-effective, convenient and hygienic means of separating food waste at source and diverting it from landfill”.

He estimates that local authorities could save an average £19 per household by promoting the use of FWDs, rather than refuse bins, for food waste, while it would cost a relatively small amount – less than £1 per household – for water companies to process the resulting waste material. But there are other environmental benefits too.

Although at present, landfill takes the bulk of our food waste, a sizable amount of our unwanted or out-of-date food is composted. Yet, according to Evans, if the bulk of food waste were to be put down the sink and turned into “sludge” instead, the resulting anaerobic digestion would turn our waste food into biogas containing 65 percent methane that could be used to generate electricity.

While both composting and sink-based waste disposal methods have undoubted commercial potential, Evans concludes that the long-term environmental benefits of biogas to the country not only outweigh those of composting, but also outstrip the inevitable extra cost of FWDs to water companies. Under InSinkErator’s proposals to Government and the water industry, these extra costs would be refunded in full. Furthermore, for many people living in flats without gardens, composting is not an option, nor does it produce the usable biogas that Evans refers to. Despite the scientific evidence however, Joe Ferrara, managing director of InSinkErator’s European operation, believes that there is “a conspiracy of silence” regarding potential longer-term environmental benefits of FWDs in comparison with composting.

For local authorities, the issue of waste disposal is enormous. Perpetually harangued by householders over the inconvenience – and potential health issues – of fortnightly general refuse collections and hectored by Government over mounting EU waste regulation and fines, rubbish is fast becoming a political football.

Yet H&W appears to have taken a brave lead on the issue of food waste. Back in 2005, it launched Sink Your Waste a pioneering experiment in domestic FWD use as part of a far broader campaign to offer households more of a choice in how their food waste is disposed of.

Aided by a cash incentive to householders and developers, take-up of FWDs has already exceeded 1 600 units in the area. Many of the householders who have chosen to have units installed have been those for whom composting – another method encouraged by H&W – is not practical.

Earlier this year, and partly on the back of the experiment, the water and environmental consultancy WRC announced the launch of a three-year collaborative research programme into the impact of using sewers for widespread food waste disposal. Its stakeholder partners in the research, which seeks to widen the debate over FWDs, include the water companies, H&W itself plus other interested local authorities, Defra and both householder and commercial users. In the country as a whole though, the picture is mixed.

While Kensington, Swindon and NorthWest Leicestershire have been positive in their approach to FWDs, and a small number of local authorities have specified waste disposal units in their new build programmes – particularly in the provision of flats – not all authorities are prepared to take a lead.

When it comes to the water companies themselves – many of whom take the view that FWDs merely represent an extra cost with no extra advantages – the hostility to imposing an extra burden on the UK’s outdated water and sewage systems is unmistakable. But is the case against water-based waste disposal actually proven?

When Thames Water recently opposed the installation of FWDs in 30,000 new homes in Swindon, it based its opposition on the increased water use, even though the Chartered Institution of Water and Environmental Management concluded in 2004 that “…the change in water usage associated with operations of FWD has been measured to be trivial or not significant”.

If the water companies fear that food waste down the sink merely adds to the cost of sewage and runs the risk of clogging up sewers that can’t always cope with heavy rainwater, let alone chicken bones, the consumer viewpoint is rather more complex. Although, in recent years, manufacturers say they have considerably reduced the noise associated with FWDs, as well as significantly increasing their reliability, fears over extra decibels in the already appliance-packed modern kitchen, routinely blocked sinks and even bent spoons may still be widespread.

According to Jeremy Howell-Thomas, project development officer at H&W’s waste management services department though, when faced with rotting and smelly food in their bin and no prospect of a collection for another 13 days, most householders are pragmatic.

“Initial resistance to the idea is soon overcome when you explain the process and the positive impact on 
their carbon footprint…people see food waste disposers as a way to mitigate the effects of an alternate weekly collection – not having to have a decaying chicken carcase in their bin for two weeks. “And there is another factor here too. If US consumers were once more convenience-oriented than their UK cousins, then in recent times, we have surely caught up. The 30 percent penetration of dishwashers in UK kitchens together with the relentless rise of the ready-prepared meal suggests that we too are cash rich and time-poor and, like the Americans, have an automatic buy-in to labour-saving devices.

InSinkErator believes that EU implementation of the Landfill Directive will lead to fines for the UK and that any such sanctions may change behaviour. As Joe Ferrara, who says that lobbying is now a big part of his job, puts it: “Fines to Brussels will have to be paid unless the UK quickly finds solutions to the challenging targets of diverting organic waste from landfill.” But an implicit threat from Europe may not be enough to clinch the debate over waste disposals to the satisfaction of all stakeholders.

For the present, the economic and environmental case for FWDs is not proven and, until the “helicopter view” is taken by UK plc the entire debate over food waste remains in danger of being obscured by sharp factional interests.

This article was published in The Chartered Institution of Wastes Management, November 2008.

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