Open windrow composting (OWC), where the surfaces on which the deposits are stored are sealed against leachate but the piles themselves are open to the elements, is already widely used by local authorities. But increasing numbers of them are not waiting for the Government’s new technology pilots to announce their conclusions but are choosing IVC on the basis of extensive use in Europe during the past decade.
IVC makes a significant contribution to landfill avoidance because, unlike OWC, it allows a wide variety of waste stream intake, including cardboard, kitchen and, subject to regulations, animal waste.
A relatively simple and technically predictable process, IVC essentially does nothing more than accelerating what nature would have done anyway – but with the added assurance of producing a consistently high-grade end-product which ticks all the boxes for stability, environmental considerations such as odour, and universality of application for agriculture, horticulture and turf-based amenities.
It also represents a guaranteed method of reducing the UK’s total greenhouse gas emissions: one tonne of biodegradable waste produces between 200 and 400m3 of landfill methane. In 2001, landfill sites released 25% of the UK’s methane emissions – that’s a gas 20% more potent than carbon dioxide, representing 2% of the total volume of greenhouse gases emitted by the UK.
The latest IVC plant in the UK is officially opened this month by LondonWaste EcoPark, a 43-acre site in London offering an integrated approach to the management of north London’s waste. The EcoPark Compost Centre will divert 30,000 tonnes of Londoners’ kitchen and green waste from landfill per year. In less than 14 weeks, it is intended that volume will be cut by 62% and PAS 100 quality compost produced.
The plant, which is designed, built and operated by Agrivert, is owned by LondonWaste and primarily serves north London authorities which have chosen centralised composting to augment existing waste management solutions. It will help to achieve 2005/06 recycling and composting targets and will help the capital manage its waste locally.
Agrivert is currently working with 14 local authorities and another 30-plus utilities and waste companies. It says the deciding factors in the system’s favour are the simplicity of the corrosion-free design, low cost, odour control and opportunities for expanding the plant, which new regulations, greater volumes or changes in the waste stream may necessitate.
But there is also a less tangible, but equally important, advantage to in-vessel composting: public relations.
Alexander Maddan, founder and MD of Agrivert, says: “It allows local authorities to be good neighbours. Odour has often been an issue with OWC sites, despite their being deliberately situated away from centres of population, but IVC plants can be operated close to an urban area – the source of the wast