BioCycle December 2006, Vol. 47, No. 12, p. 59
Trends indicate a major shortfall in composting capacity in the UK, especially for in-vessel plants that process food catering residuals. More government action is needed to realize the potential.
Peter White

THE LATEST SURVEY into the status of biological waste treatment in the United Kingdom (UK) shows that composting is playing a vital role increasing the amount of waste recycled … BUT the British Government needs to help the industry expand capacity if the UK will meet its landfill diversion targets. Performed by M.E.L. Ltd for the UK Composting Association and funded by the Environment Agency and WRAP (Waste & Resources Action Programme), the survey clearly indicates the important role that the industry has in moving the UK to greater sustainability.
The principal driver for growth has been the European Union’s Landfill Directive. For the year 2004/05, composting increased from 1.97 million tonnes (Mt) to 2.67 Mt – a 35 percent increase. The total is now 2.6 times the amount composted in 2000/01. According to the Composting Association there are about 450 composting sites in the UK.
In 2004/05, the industry was dominated by centralized sites (65 percent), mainly run by dedicated compost producers (29 percent) and waste management companies (21 percent). In 2003/04, 44 percent of all organic waste was treated at dedicated composting sites, rising to 66 percent in 2004/05. Despite representing under half of UK sites, on-farm composting has experienced continued growth in the quantity of waste managed, with a 40 percent increase. However, due to the growth in the overall amount being processed at UK sites, on-farm processing still represented only 13 percent of the overall organic waste processed in 2004/05.
The data suggest that small specialist companies continue to dominate the industry. The majority of composting businesses (74 percent) had sales of less than a million pounds, with the collective figure for the industry estimated to be around £180 million a year.
Dedicated composting companies employed the greatest number of people with 45 percent of all employees, with most companies having between one and five people. Again, this suggests that the industry consists of small companies with only a small workforce. Collectively it was estimated that over 500 people were employed within the firms responding to the survey, translating to an industrywide estimate of between 2,000 and 8,000 people.
A substantial increase in in-vessel composting was noted, treating 23 percent of the total amount of waste composted in 2004/05, an almost three-fold increase from the previous year. This represented 11 percent of all sites. Open air mechanically turned windrow processes remained the dominant technique at 64 percent of all sites, processing an estimated throughput of 1.61 Mt, or 60 percent of all composted waste in the UK. Notably the total amount processed using the open air mechanically turned windrow processes remained static between 2003/04 and 2004/05.
FEEDSTOCK SOURCES
Organic waste from households represented the majority (82 percent) of feedstock at 2.18 Mt out of a total of 2.67 Mt. The quantity of organic residuals derived from household waste recycling centers accounted for 42 percent of all organics collected for composting. Garden waste collections from curbside represented 0.78 Mt accounting for 29 percent of the overall quantity of organic waste composted. Despite these increases, there was no notable increase in the amount of commercial organic waste collected for composting, stabilizing at 0.43 Mt (0.44 Mt in 2003/04).
Of the responding local authorities with waste collection responsibilities, 75 percent had a separate organics curbside collection in 2004/05, an increase of 47 percent from 2003/04. Of this 75 percent of authorities, 30 percent ran a separate organics collection at their HWRCs (household waste recycling center where members of the public can bring green waste by car) in addition to the curbside schemes.
Overall 67 percent of UK local authorities with a green waste curbside collection accepted exclusively household garden waste, 16 percent accepted garden waste and paper and cardboard, and just seven percent accepted both household garden and food waste. The few (3.5 percent) local authorities operating a “food waste only” curbside collection were all English authorities. Just 3 percent of local authorities collected mixed unsegregated residual waste at the curbside for biological treatment. At face value, these trends are encouraging; however, the predominance of green waste collected at HWRCs suggests that during 2004/05 the composting industry remained largely reliant on householders participating in “bring schemes.”
Nonhousehold municipal waste made a very small contribution (2.4 percent). As these wastes will count towards local authorities’ landfill targets, and seem likely to have a high biodegradable content (due to the input from catering establishments and the like), separate collection infrastructure for these wastes should be considered. The suggestion by DEFRA (Department for Environment, Food and Rural Affairs) in the recent progress review of its Waste Strategy 2000 that local authorities should have more responsibility for improving waste diversion from small and medium-sized enterprises is welcomed.
The average curbside organics scheme performance rate for 2004/05 was 126 kg/household (hh)/annum of waste collected – a substantial increase on the 60 kg reported in the previous year. Preliminary calculations suggest that this was equal to a 21 percent diversion rate of the available household waste.
HOME COMPOSTING
Of the local authorities that replied to this year’s survey, 95 percent claimed to promote home composting. Of these, 70 percent distributed leaflets and used posters as promotional media. This was most popular in Wales with 88 percent of authorities using this approach, compared to just 43 percent in Northern Ireland. Distributing bins/receptacles for composting at a discounted price was the next most active form of promotion with 68 percent of local authorities that promote home composting across the UK doing so. In Scotland that was true for just 44 percent of responding authorities.
Although the survey suggested that 75 percent of local authorities with collection responsibilities operated a separate organics curbside collection scheme, 95 percent of the responding authorities also claimed to promote home composting actively, with the vast majority (89 percent) targeting the whole authority area. Potential “conflicts” between separate collection and the promotion of home composting is often cited by the industry. Although this survey did not explore this to any great extent, the documented increase in curbside collection and continued promotion of home composting by local authorities suggests that they may have complementary roles. The sale of discounted composting bins and distribution of posters and leaflets were a key feature across the UK, with Wales focusing on a help line and Scotland distributing bins free of charge.
Even though each of the four nations within the United Kingdom (England, Scotland, Wales and Northern Ireland) has different waste strategies, educational initiatives, geography and waste composition, very similar quantities of waste were composted on a per household basis. In all cases, a substantial increase from the previous year was noted, although marked regional differences remained.
COMPOST MARKETS
Data from the survey suggest that the UK composting industry manufactures a diverse range of products. The majority of compost was manufactured as a soil conditioner (37 percent), followed by a constituent in growing media at 29 percent. Compared with previous years the most noticeable increase in product was for turf dressing (rising six-fold from 0.015 Mt to 0.094 Mt), and for topsoil/subsoil manufacture which jumped three-fold, from 0.068 Mt in 2003/04 to 0.198 Mt in 2004/05. However, these products represented relatively small proportions of the overall products manufactured at 69 percent and 12 percent respectively. It should be highlighted that turf dressing product, which soared compared with the previous year, was distributed to horticulture and landscaping markets as well as sports turf markets.
The biggest growth took place in high value markets which included amateur and professional horticulture, landscaping and sport turf applications. For both amateur horticulture and landscaping the quantities more than doubled between 2003/04 and 2004/05, representing on average 58 percent. Sports turf and landfill engineering outlets both saw a reduction in the overall amount for 2004/05 compared to 2003/04.
Agriculture remained the largest single outlet receiving 26 percent of all composted products, with 89 percent of compost produced at on-farm facilities used in agricultural outlets. Landfill engineering represented just 15 percent of the outlet for composted waste.
These results of this survey are heartening but indicate that there is still a long way to go for British composting. The survey shows that there is going to be a major capacity shortfall for composting in the UK, especially for the in-vessel plants needed to treat catering waste. We lag behind our neighbors in Europe and will fall further back unless a number of facilities are built to manage the amounts of waste needed for the country to meet the targets set for it by the EU Landfill Directive. It is up to the Government to ensure that composters have the tools to realize the potential that everyone knows exists within the industry.
Peter White is Communications Manager for the Composting Association based in Northamptonshire, United Kingdom. The State of Composting in the UK 2004/5 can be downloaded from the Composting Association’s website www.compost.org.uk.