To ask the Secretary of State for Environment, Food and Rural Affairs what estimate he has made of levels of emission of bio-aerosols from open windrow composting sites in the last period for which figures are available; what assessment he has made of implications for (a) human and (b) animal health of such emissions; and what guidelines his Department issues to planning authorities on applications for new open windrow composting sites. (207158)

[holding answer 22 May 2008]: There are no estimates of emissions of bioaerosols from open windrow composting sites for any period.

In 2004 DEFRA published an independent study, “Review of the Environmental and Health Effects of Waste Management”, which concluded that on the evidence from studies so far, the treatment of municipal solid waste has at most a minor effect on health particularly when compared with other health risks associated with ordinary day-to-day living. In relation to composting, the study acknowledges that this an area where there has been less work and the science is less certain than for other waste management activities. The report is available on DEFRA’s website at:

http://www.defra.gov.uk/environment/waste/research/health/pdf/health-report.pdf

This is the most up to date source of information on open windrow composting sites.

Good site management is important in minimising risks to the environment and health from composting facilities. In 2005, the Composting Association published the Composting Industry Code of Practice, which brings together legislative requirements and good management practice to support the professional operation of composting facilities.

The Environment Agency has taken a position that there will be a presumption against permitting (and to object to any application) of any new composting process (or modification to an existing process) where the boundary of the facility is within 250 m of a workplace or the boundary of a dwelling, unless the application is accompanied by a site-specific risk assessment, based on clear, independent scientific evidence which show that the bio-aerosol levels are and can be maintained at appropriate levels at the dwelling or workplace.

In addition, Planning Policy Statement (PPS) 10 and companion guide provides guidance on waste planning. Environment Agency’s position indicates that any application with 250 m would need a detailed risk assessment showing how bioaerosol emissions would be managed and reduced at sensitive receptors. Clearly open windrow composting would not allow sufficient management of emissions so would not be acceptable close to a dwelling or workplace.