Since January 2015, separate collection of organic waste is mandatory in Germany. The implementation, however, has been rather slow, and not all municipalities provide separate biowaste collection schemes yet. The German association for compostable products ‘Verbund kompostierbare Produkte e.V.’ therefore recently called for municipalities to implement the separate collection of biowaste and support the use of compostable biowaste bags for the collection of organic waste in households. Even though the use of these bags is explicitly allowed in the German Organic Waste Regulation, many waste companies and municipalities are hesitant to accept these solutions. A quick glance at Italy, however, will prove those hesitations to be unfounded.

The project ‘Milano Recycle City’, which was rolled-out in Italy’s second largest city Milan in 2012, very clearly demonstrates the many benefits of using compostable biowaste bags for the collection of organic waste. It did not only provide all households of Milan with a clean, hygienic, and easy way to dispose of their organic kitchen waste, it also increased the amount of separately collected biowaste immensely over the first 18 month of the project.

The contamination rate of the organic waste stream was reduced drastically, while other waste streams were kept cleaner. Most importantly, more organic waste was diverted from landfills, where it otherwise would be a huge source of greenhouse gas emissions. The project has exceeded all expectations, and Milan reached a 53.5 percent separate collection rate in 2015, the main contribution of which was food waste.

The use of compostable plastic biowaste bags has another surprising side effect: By keeping the organic waste moist (compared to paper bags, which usually dry out the content) a lot of the caloric value stays in the waste and ensures higher yields, for example in anaerobic digestion (AD) plants for biogas production.

The integration of AD and composting is seen by many experts as the best way forward, as explained by Alberto Confalonieri from the Scuala Agraria in Italy at the Plastic & Biowaste Conference in Copenhagen earlier this year. Biowaste is first being treated in an AD plant to produce biogas. The remaining digestate is then transferred to industrial composting plants where it is turned into valuable compost that serves as fertiliser and soil improver for the growth of new plants for food, feed, and material uses.

A recently published report on the separate waste collection systems in 28 EU countries conducted by BiPRO and commissioned by the European Commission shows that collection systems for biowaste still vary widely among all 28 EU Member States. However, it also shows that the separate collection of organic waste increases the overall amounts of separately collected (dry) waste and hence increases the recycling targets. This shows how crucial both, an efficient technical waste management infrastructure as well as mandatory separate collection of biowaste, are in order to reach the recycling targets set out in the European Waste Directive. The higher the volume of separately collected organic waste, the higher the incentive to set up systems to treat the waste in an efficient manner and to achieve the best economical and environmental outcomes.