A Future for Biowaste Management?

By Dr. David Tompkins, Bioresources Development Manager at AquaEnviro

The past twenty years have seen massive change in biowaste management in the UK, starting with the introduction of the landfill tax in 1996. Subsequent European Directives introduced targets to reduce the landfilling of biodegradable municipal waste, set out recycling and recovery principles and then introduced recycling targets. The growth of the UK’s composting sector and (to a lesser extent) more recently developed AD sector can be seen as responses to these policies. 

One thing the policies have not done (and, in my view, should not do) is dictate the method by which their outcomes should be achieved. This means that technological and economic drivers can take us in slightly unexpected directions. My local authority offers kerbside collection for a limited range of dry recyclables, I have a paid-for green waste collection and no separate food waste collection. Instead, a new facility is being constructed to mechanically separate mixed waste - including the (more-or-less) biodegradable fraction, which will then be processed through AD. The resulting digestate will be de-watered and combusted in the adjoining EfW facility, with the liquor treated on site prior to discharge. Overall, this offers the appealing prospect of (effectively) zero waste to landfill and extract some additional recyclates from the mixed waste stream - but the nutrient and organic matter value in the biowaste is lost back into planetary cycles, rather than being retained in local agricultural cycles. There is also a huge risk of sending mixed messages to an already confused public. Why should we continue to separate our wastes for recycling when there’s a shiny new facility that we’re told will separate the material for us?

That's where we are - but where will we be in twenty years? I hope that we will have got to grips with climate change (irrespective of any temporary glitches in the White House and Westminster), which means putting carbon at the centre of economic planning and policy. This will have to mean reductions in food waste, which will mean changing consumer and retailer behaviours. Retailers cannot be blamed for trying to extract as much cash from consumers as they possibly can, but our collective approach to resource use can only be described as ‘irresponsible’. ‘Climate conscious consumerism’ can be our only possible future. 

What this means for biowaste is impossible to predict with any accuracy, but a split between ‘artisanal’ or community-based businesses capable of valorizing low volumes of discrete material streams (e.g. coffee grounds) will have to run alongside much larger industry-based valorization approaches where large volumes of homogenous material streams are predictably produced (e.g. brewers’ grains). I can’t imagine a future where householders are asked to keep different types of food waste separate for collection, and with OFWAT currently prodding the hornets’ nest of co-digestion under the guise of market development for sewage sludges it is very likely that we will see a nationwide re-think of in-sink food waste disposal. If the resulting biosolids were returned to agricultural land (and we forget about the agronomically-available nitrogen that is lost during wastewater treatment), then the net environmental outcome might be positive – but the land bank cannot be guaranteed, and water companies are already investing in alternative approaches to extracting energy from this material, leaving residues with little or no organic matter or fertilizing value. 

In summary, what I hope we will see from any future waste, industrial, bioeconomy or circular economy policy is a clearly articulated outcome, based on the need to address climate change. This must be as unambiguous as possible, pick no winners and be accompanied by a willingness and ability to support the major changes to business and consumer behavior that are needed.

AquaEnviro is a partner of the RRfW AVAnD project lead be the University of Lancaster. RRfW coordinates the co-creation process for a shared vision for waste and resource management in the UK and welcomes perspectives from all stakeholders including industry, government and the general public. Interested to share your views in an RRfW blogpost? Contact us to find out more!