In Aarhus, the second largest city in Denmark, potatoes, herbs and tomatoes grow in large PVC pipes. The scene is a VinylPlus®-supported project, that has collected partners amongst academics, architects, local authorities and industry, and that aims to establish sustainable food production with reused PVC building waste.
Urbanisation has highlighted a forthcoming, major challenge: how can we sustainably provide food to growing cities? We find an answer in urban agriculture. The Food and Agriculture Organization of the United Nations (FAO) estimates that today, 800 million people worldwide have taken on this innovative form of local food production. Its advantages could be cause for its popular use. Transport, packaging and land-use is minimised, which has a positive impact on the Earth’s climate. Growing one’s own produce also helps low-income urban residents save money on food purchases.
At the root of urban agriculture lies rigid PVC building waste. Discarded pipes and gutters are readily available and free worldwide, and PVC’s unsurpassed durability, water suitability and light weight have made it the material of choice for the do-it-yourself crowd and professional urban farms. For years, creative ideas combining crops and PVC building waste have sprouted across the globe: Lyon’s ReFarmers grow vegetables using PVC for high-end European restaurants, and the Brussels-based project, Aquaponiris, uses PVC pipes to combine growing vegetables and fish farming in a self-sufficient system.
Now, with VinylPlus’ support, the Urban Agriculture project investigates whether a more systematic use of PVC building waste in urban agriculture is feasible. The project branches into the design and construction of PVC building waste prototypes, so as to scientifically evaluate sustainability potentials, and also establishes partnerships with architects, local authorities, waste owners and PVC converters. Current partners include the PVC Information Council Denmark, architects Kåre Sølvsten and Maja Sønderskov, Professor Marianne Thomsen and PhD student Daina Romeo from Aarhus University, Nordisk Wavin, and the city of Aarhus.
Aarhus actively explores the establishment of urban agriculture in big cities, as the municipality is greatly interested in the interaction between itself, business and civil society. It was therefore a natural step for the city to participate in the VinylPlus project, explains Christian Brødsgaard Eschen, Project Manager, City of Aarhus. "This project represents a very nice narrative of how businesses try to reuse their waste. When waste can be used for urban agriculture, it means that we consume less and that we reduce the climate burden," says Mr. Eschen. The climate benefits have already been confirmed by Aarhus University, that in a recent report concluded that “the reuse of PVC from construction to agriculture is a promising way of slowing the flows, one of the indispensable steps towards a circular economy […] By giving it a second life, the utility of the material is maintained and can provide additional benefits to people.”
Faced with solving the challenges of collecting the right PVC waste fractions suitable for urban agriculture, Mr Eschen highlights Aarhus’ waste redistribution centre, ReUse. "I think that it would be ideal if there was a similar exchange centre for PVC building waste where the citizens can come and pick up sorted PVC building waste, which they can use to build urban agriculture systems in their communities," says Eschen. He also sees potential in emerging social-economic companies for which unemployed citizens can work to manufacture and sell vertical growing systems, thus linking the circular economy to sustainable food production.
In 2018, in cooperation with the PVC Information Council Denmark and Nordisk Wavin, Aarhus installed the first PVC prototype in which plants such as potatoes, tomatoes and herbs successfully grow. Through this partnership, VinylPlus’ project will next plan the collection, sorting and distributing of PVC building waste for simple, urban agriculture prototypes accessible to everyone.