Evaluating phosphorus removal of two bioretention systems for stormwater discharge into surface water: a case study for emergent SUDS teechnologies in Copenhagen

The Municipality of Copenhagen together with the local water utility have planned a climate adaptation project on a street in Copenhagen, Rantzausgade, to manage stormwater and test two
nature-based solutions for treating stormwater for discharge into fresh water lakes in the center of the city. The Rantzausgade Climate Adaptation project (RCAP) will include two different sustainable urban drainage systems (SUDS) which offer different approaches to stormwater management and treatment. One system is a filter soil rain garden system which utilizes natural soil processes to remove pollutants from stormwater. The second system is a constructed, horizontal sub-surface flow wetland which employs a prefilter, with a chemical composition similar to zeolites, and a main media similar to LECA and Filtralite P to filter and sorb pollutants. The two systems were compared with regards to their treatment efficiency, hydraulic capacities, and maintenance demands.