Oosterhoff, Hendrik; Golsteijn, Laura; Blondel, Elise; Gavrila, Ionela

Allseas is a world-leading contractor in offshore pipeline installation, heavy lift and subsea construction. Being at the sea every day, Allseas is concerned about the future of the oceans. Therefore, they actively support the global effort to clean oceans of plastic by developing a system to collect plastic particles in rivers and waterways before they can spread to the seas and oceans and break up. In scope of the “LIFE SouPLess” (Sustainable riverine PLastics removal and management) project, Allseas and PRé Sustainability collaborated to assess the environmental impact of their riverine plastic litter collection system. The collection system is currently operated in the Nieuwe Maas in Rotterdam, the Netherlands. The system consists of two booms, a 200 meter long boom and a 12 m long boom, that gather plastic from the river and guide it into a cage, which is regularly emptied. Too secure a holistic assessment of the system, the aim was to evaluate (I) the environmental impact of the system through an LCA, (II) the environmental benefits of the plastic removal and (III) the legislative context of the plastic removal system. Additionally, since no method exists to quantify the environmental benefits of the plastic removal, the quantitative LCA was combined with a qualitative assessment of the plastic removal. The study identifies environmental hotspots, i.e. the materials, processes and life cycle stages that have the highest environmental impact. In an online scenario tool, designers can explore the influence of different material choices, production locations (affecting for instance the electricity mix and transport distance), recycling grade, or lifetime expectancy.