The site of 'Ceuvel Volharding' is a former shipyard, an abandoned and polluted site in the ports of Buiksloterham. In economically better times, this place was supposed to be cleaned up in the traditional way and then built upon. In 2012, the planned urban development came to a halt and the site was awaiting development, which offered opportunities for alternative solutions. The Municipality of Amsterdam made the land available for the most innovative plan for 10 years . The plan 'Purifying Park De Ceuvel' with its breeding ground in written-off houseboats was put forward by a very varied and interesting group of people who make this part of Amsterdam North a great active and creative place. The technique of phytoremediation, in which plants are used to extract pollution from the soil, offers a solution for this polluted area and a bio-fermentation installation will convert biomass into energy. For example, the site is a test location for research into organic soil purification and biomass production at Ghent University. And after ten years, the entire location will be returned to the city of Amsterdam much cleaner. DELVA is responsible for the design, research, planting and maintenance of the purifying park.