Background The Community Strategy for Waste Management states that recycling activities should be promoted across the Community. Composting is an important means of recycling biodegradable municipal waste for agricultural use, which also saves resources via its substitution for commercial fertilisers. However, the public must first be convinced of the safety and environmental benefits of recycled products. After the prevention of waste generation, the LIFE-Environment Programme considers initiatives promoting recycling - including composting – as having the highest priority among waste management projects. Within the realm of recycling, projects that focus on source separation of biodegradable waste and improving compost quality are thus of great importance. It has been estimated that 10% of the total nutrient input to Danish agriculture can be substituted by recycling organic waste, including urine. In other Community regions where agricultural production for export is smaller, the potential for recycling could constitute an even larger fraction of the nutrients needed to support sustainable local agricultural production. Organic livestock farms produce animal fodder as their main crop product and only a minor part of the area can be used for other products. Fertilisation is provided by manure from the animals. In organic plant production, the main products are for human consumption and there is no animal manure production available from the farm itself. A key factor for the sustainability of this kind of food production is therefore recycling of organic waste from the consumers as fertiliser for the crops. Objectives The Short-Circuit project intended to develop three new full-scale source separation and composting systems for urban organic waste, focussing on recycling nutrients and carbon from the solid organic waste, including human faeces, as these resources are not extensively utilised by most people in the European Community. Aarstiderne Ltd., a business that delivers boxes of vegetables to households once a week, was to integrate a waste collection system in their distribution of organic vegetables and other foods. Krogerup Farm, an Aarstiderne supplier, was to receive organic waste from customers, compost it and use it as a supplementary soil amelioration product and fertiliser. The project was also to develop a system for the transportation of source-separated household waste and faeces from a newly established ecological settlement, Munksoegaard, to an experimental farm in Taastrup for sanitation, semi-closed composting, and end-use in field experiments. A high-tech composting plant in Holbæk, using source-separated waste from Kgs. Enghave, Holbæk and Ballerup, was to be established. The project was also to organise public demonstrations of the systems, involving 11,400 households within the greater Copenhagen area. The systems would be designed to optimise the recycling of organic household waste by establishing a close relationship between the sources, households, and the end-users – mainly farms and market gardens. Short-Circuit was to establish best practice in composting, determining optimal conditions for reduction and removal of pathogenic micro-organisms in compost to be used for agricultural purposes. This was to be accomplished by the monitoring of the composting process and by chemical and microbiological analysis of the finished compost products. Growth experiments with amendments to the soil of the different types of compost produced in the subprojects was to determine the positive effects on crop production and the soil ecosystem as well as the fate of organic micro-pollutants and pathogenic micro-organisms. Results The project employed a number of innovative techniques related to a) waste collection, b) source separation, and c) composting. The methods were a very basic but effective collection device used by Aarstiderne to collect organic residues from their customers, a relatively simple on-farm composting system, a newly developed biogas/composting plant (AIKAN), and computer modelling (using Orware software) to analyse the environmental impact of different waste management strategies. The project employed existing technology but in new processes, so it had a strong demonstrational character. Aarstiderne externally mounted a simple metal plate fitting on the left rear door of one of their delivery vans. They then placed an ordinary wheelie bin on the plate and the organic waste collected from customers was then emptied into it. Customers were supplied with compostable waste-bags and a 5 l green bucket with a lid to store the waste in. The customers delivered the compostable bags in the buckets, thereby avoiding spills and odours. Initially, the van only collected the waste one day a week, but by the end of the project, it was collecting waste three days a week. The project tested several techniques for re-circulating organic waste. Some of the partners will continue to be involved in recycling activities after the end of the project. One of the remaining worries about this sort of activity is the acceptance by consumers of the extra work involved in waste recycling. Demands from supervising authorities with regard to the level of hygienisation of compost may also be a concern. The project has shown that it is possible to achieve adequate hygienisation of compost, although it may be difficult to achieve the required high temperatures in the composting process. One major challenge for the project management was the incorporation of a new partner, Solum A/S, in the project. The original composting service partner, R98, decided to opt-out of local authorities to permit construction of a composting plant within the Kg. Enghave area. Luckily, KVL was already acquainted with Solum A/S, a leading composting business in Denmark. In the end, their AIKAN plant is working well. Their activities and the computer modelling work using the Orware waste management software, combined with the project results, contribute to the discussion currently taking place in the country on incineration versus recycling of household waste.