Background Without new initiatives, waste volumes are projected to continue to rise in the foreseeable future. In addition to requiring valuable space, the management of waste releases numerous pollutants to air, water and soil including greenhouse gas emissions from landfills and waste transportation. Waste also represents a loss of valuable resources, many of which are scarce and could otherwise be recovered and recycled to help us reduce our demand for virgin raw materials. The 6th Environment Action programme considers biodegradable household waste as a specific "priority" waste stream, states that legislative initiatives must be developed in order to treat municipal wastes in a different way than landfilling. To achieve high levels of composting, re-use, recycling of biodegradable household waste, as well as high rates of diversion of such waste from landfills, both widespread separate collection facilities as well as adequate markets for the collected material need to be established. Objectives The COMWASTE project aimed to address the above issues by developing and implementing an innovative system for separate collection and composting at source in the Attica region of Athens. Specifically, the project aimed to divert organic waste from landfilling and contribute to fulfilling its recycling strategies. Additionally, the project was to provide information to local authorities that will assist in introducing successful and cost-effective home composting and biodegradable waste separation schemes in their localities. Finally, the project would increase the participation of householders in waste management. Results A suitable and effective prototype system for the simultaneous separate collection and composting at source of the household biodegradable organics was designed, constructed and installed in selected households. This was the first application of such a system (simultaneous collection/composting at source) in the country. Vitally, household members became familiar with the practice of separate collection/composting of their waste at source, getting used to this practice as part of their daily activities (common daily practice). First of all, all the potential composting methods, techniques and systems available on the market that could be used for the household composting were analysed in order to determine the most suitable and efficient system. The list of the various alternatives was then whittled down to three, which were then lab-tested to assess their operational functions and performance. Following this, the first version of the components of a prototype system were manufactured and tested. Next, an extensive information campaign was set up in the municipalities concerned, involving direct mailing and direct visits to households. Additionally, workshops were organised and advertisements were taken out in newspapers and on the radio. Then, the households that would participate in the programme were selected via a procedure that ensured that the participants were representative of the various sorts of households in the region. Members of these households were provided with the prototype system and trained in its use. They were also given special additives that were used for the efficient development of the process. In particular, the householders fed the system with the appropriate biodegradable waste generated at their kitchen together with Greek zeolite of a specific particle size and dose in order to eliminate the odour and improve the quality of the final compost product. The individual and the overall results of the laboratory analyses indicated that the compost is of sufficiently high quality (as was confirmed by the values of the quantitative and qualitative characteristics and the non-presence of phytotoxicity) as to fulfil the legislative quality standards for its safe use. Finally, a framework of guidelines and specifications was developed for the implementation of the programme on a larger scale. This was supplied to local authorities to aid in the application of the prototype systems in their communities.