The lines, which are a result of a £1 million investment, have been installed at two of Veolia’s sites in Hampshire at Little Bushy Warren and Chilbolton Down; Padworth in West Berkshire; and Woodlands in East Sussex.
According to the waste and recycling company, the effectiveness of the cleaning lines means that the composting sites will be more efficient, with disposal costs “significantly lowered.”
Compost oversize is the term used to describe the larger, woody fraction of material that is leftover after the composting process, once the valuable compost product has been screened out.
It happens when the collected organic material contains contamination, such as plastic and metal, and often ends up in landfill, according to Veolia.
Currently, around 25% (30,000 tonnes) of Veolia’s collected green waste ends up as oversize after composting at the four plants.
By using the fixed cleaning lines to remove contamination, Veolia said that the compost oversize arising at these four facilities can be transformed into a clean wood product such as PAS100 mulch for gardening and landscaping.
It could also be used as renewable biomass fuel for electricity and heating which replaces virgin alternatives such as woodchip and bark.
To date, more than 55,000 tonnes of contaminated compost oversize has been processed through the cleaning lines.
Donald Macphail, chief operating officer for treatment at Veolia said: “Composting sites provide the perfect example of a circular economy, and the need to efficiently process this material is likely to increase with the prospect of green waste becoming free to collect and on a more regular basis, as pledged in the government’s Resources and Waste Strategy
“By backing this new innovation, we have increased the effectiveness of operations and will provide additional high quality sustainable wood mulch and renewable fuels. This will help horticulture and renewable energy generation and is another key step that we are taking to reduce environmental impact and advance towards a lower carbon economy.”
Veolia currently processes over 500,000 tonnes of green and food waste a year at its 11 composting sites in the UK.