[holding answer 25 January 2008]: DEFRA has not carried out any recent research on the potential hazards of re-using landfill sites for recreational land.
However, the Construction Industry Research and Information Association (CIRIA) has conducted research looking at the remedial engineering aspects associated with closed landfills and has produced a report written specifically with redevelopers in mind. The principles of the approach laid out in the report draw heavily from the substantive research conducted by the former Department of the Environment and the Environment Agency in the 1980s and 1990s.
The document (Barry et al (2001) Remedial Engineering for Closed Landfill Sites, Construction Industry Research and Information Association (CIRIA) Report C557, ISBN 0-86017-557-X) provides guidance to designers and regulators on the principal statutory, technical and environmental factors which can influence the redevelopment of former landfill sites. The report summarises that the suitability of sites for particular uses will depend on several factors such as age, depth and nature of wastes, in addition to the site's environmental setting and conventional land-use planning aspects of redevelopment.