comwastePromotion and implementation of the systems for the promotion of high-quality compost from biodegradable household waste, separated at source.
01/12/2003 - 31/08/2006

The project perfectly matches the overall targets of Greece on waste prevention and increased recycling since the project is expected to demonstrate and document the separate collection and composting at source and can lead to significant reduction in the quantity of waste going to final disposal. Three Municipalities of Attica region were quite involved in the project: Municipality of Kifissia, Municipality of Nea Halkidona and Municipality of Acharnes. The project was carried out in an appropriate pilot scale in order to demonstrate and document the feasibility of separate collection and composting at source. It consisted of 8 tasks and it lasted 27 months. The successful diversion of biodegradable wastes from landfill relies on the separation of these wastes at source. Whilst the biodegradable fraction can be extracted from mixed wastes, this is laborious and produces a contaminated product. Separation at source offers the opportunity of a high - quality clean feedstock for composting and the prospect of an uncontaminated product. A "clean" waste collected via separate collection is more likely to meet compost standards and be suitable for sale or use, bringing associated environmental benefits. 


Use of the compost end product offsets the requirement for other soil conditioners, such as peat, in agricultural and garden uses. Separation of biodegradable wastes at source also allows for the promotion of home composting or composting within small, local communities. The compostable fraction of waste is often one of the most polluting of the waste stream, and implementing such a scheme diverts waste from the traditional disposal routes such as incineration and landfill. As one of the largest fractions of household waste, diverting organic waste from landfill can also significantly contribute to meeting local recycling targets. The system that will be developed will be based on the simultaneous biodegradation and stabilization of the household organic fraction. Also it will be characterized by flexibility, convenience in using and capability to treat small quantities of waste in short time period, at households. This was the first attempt in Greece to establish such a system for simultaneous collection - composting at source and the working group tried to develop an effective, suitable and operational system and scheme in order to be the basis of a full-scale introduction in other areas in the country. The design and development of a new prototype system included all state - of - the - art notions and ideas in respect to technological and scientific aspects.


  1. Development of a prototype system for the simultaneous separation and composting of the biodegradable household waste at source, that is tailored to the needs and the specific characteristics of the densely inhabited area of the Attica Region and it is characterized by flexibility, convenience in use and capability to treat small quantities of waste in short- time period.
  2. Diversion of the organic matter of the household waste from the traditional disposal to landfills. It is estimated that a percentage up to 40% of the mixed municipal solid waste that refers to household organic waste was utilized for the production of a useful end product (compost) instead to be disposed at landfill sites. This fact lead to a significant number of environmental benefits. DELETE , as presented analytically in the Section: Direct/Quantitative environmental benefits).
  3. Contribution to meeting local recycling targets as set by the relevant EU legislation (e.g. Directive 99/31/EC) and the national strategy that demands municipal wastes to be reduced to 75 % of the total amount (by weight) produced in 1995. 
  4. Provision of information related to the household composting to all the actors involved in the field, as described analytically in the Section: “Relevance for environmentally significant issues or policy areas”.
  5. Increasing of the environmental awareness of the citizens (they take more ownership of efforts to protect the environment)
  6. Assistant to the local Authorities to introduce successful and cost-effective home composting and biodegradable waste-separation schemes in their localities.


The technology that was developed and applied through the COMWASTE project was based on the simultaneous separation, biodegradation and stabilization of the household organic fraction, at source, using an appropriate prototype system that was designed and manufactured specifically for this purpose. The prototype system was characterized by a high level of sustainability since:

  • it was based on the application of a treatment method (composting) that is time-tested successfully
  • it was based on a technology that promotes the sustainable management of waste (recovery of materials and transformation into a useful end-product which, additionally,could substitute the use of synthetic products)
  • it used a “clean” waste as feedstock for composting (organic fraction of household waste that is separated at source), fact that allows the production of an end-product of a high quality and, consequently, its unobstructed use (on the contrary, the biodegradable fraction that is extracted from mixed waste in central mechanical sorting plants may have impurities, fact that can result in the production of an end-product of a low quality with limited potential for use)
  • it was installed at any household without problems since its dimensions are similar to other household devices
  • it is convenient in using (it operates similarly to a bin used for the placement of the mixed household waste)
  • it has the capability to treat small quantities of organic wastes in a short time-period
  • the cost for its manufacturing is low
  • the cost for its operation and maintenance is low
  • its use could be placed among the daily activities of the householders, easily and smoothly.

The application of such a system can lead to the limitation of significant environmental problems, giving tactile solutions like:

  • reduction of the annoyance that occurs during the collection and transfer of the municipal solid waste,
  • lower burden of the landfill sites, in terms of quantity and polluting load, due to the reduction of the amount of municipal solid waste that are disposed,
  • increase of the operational time life of the landfills,
  • reduced generation of leachates and reduced organic load in leachates due to the decrease of the organics that are disposed,
  • reduction in the air emissions from landfills in qualitative and quantitative terms,
  • production of a product with added value deriving fromfrom waste which otherwise must be disposed at landfill sites etc.

Also, the use of the technology in large scale applications affects positively other environmental areas, since the end-product could be used for:

  1. Landscaping,
  2. land restoration,
  3. soil fertilizer and conditioner, substituting the use of synthetic fertilizers for agricultural purposes
  4. deodorant mean at landfill sites.

Finally, the range of the feedstock of the system could be expanded in order to include other waste fractions such as green waste from private and municipal gardens, private yards or municipal parks.