More data reporting needed for building waste

Production of recycled aggregate from construction, demolition and excavation waste (CDEW) rose 6% during 2003-05, according to a government survey.1 But the report says the rise is "not statistically significant" and calls for extra data reporting requirements for recyclers and operators of landfills and registered exempt sites.

The survey, carried out by Capita Symonds and WRc for the Department for Communities and Local Government, is the fourth to look at the volume, use and recycling of CDEW in England.

The amount of CDEW being sent to landfill fell by 4.5% since 2003, when the last survey was carried out (ENDS Report 358, pp 20-21 ), but the amount recycled rose 6% to 42 million tonnes. Arisings remained around 90 million tonnes.

When recycled soil is also taken into account, the amount recycled was little changed from 2001 and 2003 at about 46 million tonnes.

The number of recycling crushers continued to grow, says the report, but "the annual throughput of the average crusher has fallen since 2003, pointing to greater competition between recyclers".

The amount spread on land "apparently" dropped by 1 million tonnes to 15.5 million tonnes between 2003 and 2005 (see figure), partly because of a more "demanding" written application procedure and the introduction of new £500 fee for registered exempt sites.

The survey also found a decline in the quality of material. The ratio of graded to ungraded aggregate was 57:43, down from 2:1 in 2003. Those recyclers with access to an off-site fixed recycling centre, giving them more time to optimise recycling, achieved the highest quality aggregate.

But John Barritt, aggregates manager at the government’s Waste and Resources Action Programme, said it was an "anomaly" that the survey had recorded a decline in aggregate quality and that there is "evidence that more materials are moving up the value chain." The survey no longer reflects the complex picture of aggregate recycling which was developing as the sector was maturing, he added.

For example, washing plants that deal with some of the more difficult waste steams are not included in the survey, suggesting recycling levels are higher than those reported.

All of the survey’s findings carry wide margins of uncertainty because of a paucity of data and a low response rate, the authors warn. They stress that most of the changes are not statistically significant.

The report says the Environment Agency should change the forms used to register exempt sites to require operators to provide more information.

It also suggests making better use of site returns for licensed landfills submitted to the Agency every quarter.

To obtain better data on the operations of recycling crushers and screens, information requests should be incorporated into applications and renewals for Part B authorisations submitted to local authorities by operators under the pollution prevention and control regime.

Meanwhile, a parallel survey of other secondary and recycled aggregates was produced for DCLG by the same authors.2 It follows a similar survey for England and Wales in 2001.

The survey found that the use of waste container glass as an aggregate has increased considerably, but is still low and an extra 1 million tonnes could be used each year. A reduction in the value of packaging waste recovery notes in 2006 had "a direct and deleterious" effect on recycling glass into new containers.

Arisings of pulverised fuel ash from coal-fired power stations rose to about 5 million tonnes in line with increases in coal-generated power and it is expected that there was a further increase in 2006. In addition, "notable stockpiles" exist at power stations.

Some 2.7 million tonnes were used, including 900,000 tonnes as aggregate in concrete blocks. But some other uses, for example as a cement additive or replacement, and as a fill or in ground remediation, are being impeded by its designation as a waste, which brings it under waste management regulations (ENDS Report 382, pp 11-12 ).

The use of china clay waste as aggregate has risen despite reduced production. About 2.6 million tonnes was used in 2005, but there was still 11 million tonnes potentially available. Greater use depends on exporting the material from the south-west and overcoming related cost and logistical issues.