Closing the loop for organics

Closed loop on-site composting is an approach that hasn't yet reached its full potential, but one organisation in Yorkshire is looking to change that.

Few government edicts preoccupy the thoughts of the municipal waste and recycling sector more than the EU Landfill Directive. Most of us probably have its targets etched in our minds by now. But just in case you’ve forgotten: by 2010, biodegradable municipal waste going to landfill must be 75% of that produced in 1995; by 2013 it must be 50%, and by 2020, 3%.

It’s now widely accepted that composting in one form or another has a crucial part to play in meeting these targets. To date, the focus has been on two ends of the spectrum. On the one hand there is a push to target the homeowner to compost more – for example, the promotion of more separate household food waste collections in the recent Waste Strategy for England – and on the other there is the drive to large scale industrial composting. Both are crucial if composting levels are to be increased.

Tonnes of potential

However, one approach which has been under-exploited until now is ‘closed loop’ on-site composting of organic material by businesses and organisations which produce significant amounts of green and kitchen waste and which also have a need for compost and mulch for use on their grounds and gardens. Schools, hotels, local councils, prisons, and golf courses are often sitting on tonnes of potentially compostable material, yet it usually ends up in the most financially and environmentally costly disposal route – landfill. The challenge has been to find a way to efficiently compost this material on site, for reuse in the same location.

The recent experience of a number of demonstration projects being carried out by Recycling Action Yorkshire (RAY) suggests such an approach has huge potential to deliver major environmental benefits – beyond even those gained from reducing the amount of biodegradable waste sent to landfill.

RAY, the organisation set-up by Regional Development Agency Yorkshire Forward in 2005 to stimulate recycling businesses and markets for recycled materials, is currently operating six closed loop organic exemplar (CLOE) projects in the Yorkshire and Humber region. These projects are aimed at demonstrating the viability of closed loop organic waste management systems. RAY has been testing different methods to see what part they could potentially play in the drive to reduce the amount of biodegradable waste sent to landfill.

Calderdale rockets ahead

One local authority taking part is Calderdale Council in West Yorkshire, which has used funding from RAY to purchase an in-vessel A500 Rocket Composter for a primary school. The machine is used to compost all of the school’s green and kitchen waste for reuse in grounds maintenance and gardening projects. Annually, 1.8 tonnes of kitchen food waste will be composted along with 1 tonne of woodchip – producing 840kg of compost for use by the school.

The machine takes just 14 days to produce compost extract. This is then transferred to a conventional composter to complete the process. Diverting this amount of waste from landfill delivers CO2 savings equivalent to 2.2 tonnes. Financial savings result from no longer having to pay landfill tax and transportation costs, and from the free mulch and compost which the machine produces. Running costs for the small amount of electricity used by the machine are estimated at £19 per year.

In another CLOE project, the council is also composting all of its leaf and green waste from parks and gardens for reuse in the same locations. A thousand tonnes of leaf litter from roadside material collected by the leaf collection teams within the Calderdale area has been composted in open windrows to produce around 400 tonnes of compost for use in the council’s parks and gardens. It’s anticipated that by recycling 1,000 tonnes of this material there is a saving of £8,880 compared to landfill costs of £29,000.

For RAY, the CLOE projects are part of a wider strategy aimed at maximising composting rates throughout the region. A hands-on support programme is helping councils practice more sustainable procurement – including increased use of compost. A directory has been produced of green waste suppliers in the region to ensure those wishing to procure compost have access to up-to-date information on availability.

RAY is also working with local authorities in the region to increase their organic waste processing capacity through the delivering excellence in waste project funded by Local Government Yorkshire & Humber. Planning consultancy support is delivered to assist with planning consent and waste management licence issues.


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