London Wider Waste Strategy - London - Greater London Authority

• Although the Environment Agency sent out 20,000 questionnaires nationally and
responses were received from 18,600 respondents (93%), which is a relatively high
response rate, it should be noted that this data is used to represent all organisations
(business, industry and public sector) of all sizes across all of England and Wales.
Hence, there is a greater potential for inaccuracy when breaking down data by
region or industrial sector due to sample bias.
4.19. The limitations in the SWMAL data should be noted, especially when using it at the
regional (i.e. London) level and when considering sectoral analysis. Caution should be
exercised when quoting the figure of 7.1 million tonnes as an absolute, it should instead
be referred to as an estimate derived by survey methodology. It should also be noted
that this figure is almost six years out of date, and could now be significantly different,
although it is possible that the expected increases in commercial wastes are offset by
decreases in industrial wastes.
4.20. The size of the SWMA update survey currently being carried out is reported to be
smaller than the previous one, although the methodology is believed to be the same.
Data collection work is being carried out in April and May 2004, with reporting planned
for later in 2004.
4.21. Our discussions with the Environment Agency confirm that considerable effort has been
made in the survey to account for regional variations and sample error by statistical
means. Nevertheless, London is underrepresented in the survey and the confidence in
the regional and sectoral analysis for London could be increased by boosting the sample
for London. This would require additional data survey work within London in general,
and for specific industrial sectors which may be otherwise underrepresented in the
survey. While it is acknowledged that there will always be a degree of uncertainty
attached to data obtained by survey, the benefits of additional waste data will provide
(a) a higher level of confidence in the data (for strategy development purposes) and (b)
a more accurate baseline against which to assess the success of a Wider Waste Strategy
in future years.
Recommendation 1: It is recommended that the validity of the data on C&I waste in
London provided by the Environment Agency in the ‘Strategic Waste
Management Assessment, London’ (SWMAL) 2000 is improved by carrying out
further targeted surveys of selected waste streams relevant to London.
Preferably this should be achieved by the GLA approaching the Environment
Agency as a matter of urgency to establish whether their current survey can be
extended to cover these terms. Government should also be lobbied to provide
more resources to the Environment Agency to fund future surveys.
‘Technical Assessment for Waste Management in London’, April 2003, Enviros
4.22. This technical report uses the SWMAL data, which was reviewed above. It provides
arisings and disposal data for commercial and industrial waste, in addition to data on
construction and demolition waste and special/hazardous waste. Basic information on
current major waste transport routes for London’s recyclables is provided, plus a small
amount of information on the movements of C&I wastes. The report also details all
licensed waste facilities both within and outside of London.
4.23. An attempt was made to carry out an exercise using the Environment Agency’s Local
Waste Interrogator database, which is an on-line application designed to help local
authorities extract waste input and capacity data for their own areas. This is based on
site-return data but only provides details of the amount of waste deposited in and
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