Background Europe is facing a number of large-scale environmental problems related to waste and land-use. The amount of waste currently produced is estimated to be in the region of two billion tonnes a year, and this is increasing by some 10% annually. A significant proportion of this waste (approximately 410 million tonnes per year) relates to industrial waste. At the same time, urban areas, in which 80% of Europeans live, face a common challenge of sustainable development. Furthermore, previous industrial activity in rural areas has also created an inheritance of 52 million hectares of degraded agricultural land. Effective solutions to these environmental problems are required and these solutions will need to address high level goals, such as those linked with Europe’s commitment to the Kyoto Protocol. The latter will require measurable reductions in greenhouse gas emissions, particularly in urban areas. Objectives The objectives for this TWIRLS LIFE project focussed on demonstrating opportunities to help the EU comply with its Kyoto Protocol commitments, and identify sustainable solutions to reducing waste volumes by innovative applications of composting treatments. The potential of in-vessel composting treatment was tested as a means of re-using different types of waste to restore post-industrial and degraded land. The new approaches were tested on brownfield sites and degraded land in rural areas. Goals included the removal of industrial pollutants as well as the creation of high conservation value habitats to help enhance biodiversity in both urban and rural environments. Results The project achieved its aims and successfully demonstrated the effective use of in-vessel composting treatments for common industrial and domestic wastes. Outputs included: Simultaneous decontamination of waste during the composting process by microbial removal of organic pollutants (such as PAHs) and conversion of heavy metals into stable non-toxic forms; Demonstrating how co-composting of mixed waste streams can achieve accelerated composting and also how the incorporation of non-biodegradable wastes can be used to produce more mineral-based soil materials; Testing of innovative approaches to help match different composted waste streams with different quality end products suitable for the restoration of different ecological habitats; Regeneration of two brownfield urban sites, where previous restoration attempts had failed; Restoration of two quarries in rural areas to high conservation value habitats; Removal of pollutants from post industrial land where soil contaminated with PAHs was co-composted with organic waste to accomplish bioremediation. Smaller farm trial demonstrations were also carried out to remediate heavy metal contaminated soil by co-composting with organic wastes. Trial findings noted reduced uptake of pollutants by crops; and Creation of socio-economically beneficial areas of high biodiversity within urban and rural settings. Additional benefits in these areas included improved landscape harmonies. The project’s success at diverting wastes from landfill or incineration into environmentally-friendly compost was reflected in the TWIRL technology’s LIFE Cycle Assessment. This showed a reduction in direct greenhouse gas emissions and secondary benefits such as reductions in eutrophication, acid rain, improvements in social health etc. Quantitative data gained from the TWIRLS project confirmed that using organic waste amendments on an area of some 3 600 ha of degraded land can lead to a sustained increase of at least 20% in soil organic matter, of which up to 55% is organic carbon. The project team were also involved in lobbying for changes in UK legislation that improved options for using paper wastes in composting. Key lessons learnt during this process included the importance of forming close working relations with policy regulators in order to strengthen practitioners’ knowledge concerning policy rationale, as well as inform decision makers about opportunities to update policy mechanisms. Further information on the project can be found in the project's layman report (see "Read more" section).