Composting doubles in two years

The industry's latest "state of composting" survey comprised a 16-page questionnaire sent to all UK compost producers and a targeted sample of local authorities some 12 months ago. It covers the financial year 2001/02. Additional data were obtained from a shorter questionnaire sent to community composting operators.

The survey continues the trend for compound 25% per annum growth in the number of centralised composting facilities since 1994 (see figure). By 2001/02, there were 132 such facilities run by 83 operators. Half of these sites were operated by waste management companies, 38 were operated by dedicated compost producers and 15 by local authorities.

The median throughput of centralised composting facilities rose from 6,000 to 8,000 tonnes between 1999 and 2001. The industry continues to be dominated by many small-scale facilities.

On-farm composting is also expanding at some rate, with 78 sites in operation in 2001 against 65 in 1999. These sites usually process less than 5,000 tonnes of waste per annum and qualify for an exemption from waste management licensing. The compost is utilised on the farm.

In total, the industry processed some 1.66 million tonnes of waste in 2001/02, double the volume in 1999. The survey year coincided with new restrictions under animal by-products legislation following the outbreak of foot and mouth disease, which led many local authorities to abandon plans to collect household kitchen waste.

With regulations now in place permitting the composting of food wastes under tight controls (ENDS Report 344, p 51 ), further rapid expansion of the sector is anticipated, as local authorities face up to statutory targets on recycling and landfill diversion.

Material collected by local authorities accounted for 80% of the wastes sent for composting in 2001/02. Of this, 1.04 million tonnes was garden waste collected from civic amenity sites, with a further 152,000 tonnes collected from households by kerbside collection. Some 40% of the latter was from schemes which accepted kitchen waste.

On top of the household wastes comes a growing volume of commercial and industrial material. Some 93,000 tonnes was collected from food processors and a further 8,600 tonnes from food retailers. The survey also identified some 4,700 tonnes of paper pulp that was sent for composting.

The industry turned its 1.66 million tonnes of waste into 998,000 tonnes of product, according to the survey. Of this, one-third was used in landfill engineering and restoration. Agriculture was the second biggest outlet (see table).

The Composting Association represents many of the major operators of centralised composting facilities. Its survey concludes that the community composting sector, by contrast, accounted for less than 0.2% of the total amount of organic waste sent for composting, and that the sector is "unlikely to play a significant role" in meeting landfill Directive targets. Nonetheless, it notes the educational value of community schemes.

The report also sounds a cautionary note on mechanical/biological treatment and the extent to which it will count towards local authority recycling targets. "Ambiguous" returns received in the survey indicate that the terminology is poorly understood, the report says.