In urbanen Gebieten kann abfliessendes Regenwasser belastet sein, insbesondere auch mit gelösten organischen Spurenstoffen und Schwermetallen. Diese Substanzen werden von Gebäuden sowie Verkehrsflächen abgewaschen und können über Versickerungen in das Grundwasser gelangen. Mit einem neuen Adsorbersubstrat wurden Schwermetalle, organische Spurenstoffe und deren Transformationsprodukte aus dem Regenwasser so gut entfernt, dass sich damit neue Anwendungsbereiche für Schwammstadtkonzepte im urbanen Raum eröffnen.

A large variety of substances are used in building materials to improve their properties. In recent years, attention to organic additives used, for example, in renders, façade paints or roof sealing sheets has increased as these compounds have been detected in urban stormwater runoff and surface waters. In this paper, we show the extent of emissions induced by rain events in two study sites in Berlin. For this purpose, stormwater runoff from roofs, façades, and in storm sewers was sampled and analysed over a period of 1.5 years in two residential catchments. Results show that, in particular, the biocides diuron and terbutryn from façades, the root protection agents mecoprop and MCPA in bituminous sheeting, and zinc from roofs and façades reach concentrations in the stormwater sewer that exceed limit values for surface waters. Additionally, transformation products of the biocides were also detected. However, many other analysed substances were below the quantification limit or inconspicuous in their concentration levels. The emissions, modelled with the software COMLEAM, demonstrate that in urban areas the limit values in smaller surface waters are exceeded during wet weather. Furthermore, the orientation of the buildings to wind-driven rain is essential for the emitted load from façades. The calculated mass balances of both catchments show that a major portion of all substances remains on-site and infiltrates diffusely or in swales, while the remaining portion is discharged to stormwater sewers. For example, in one of the two study sites, <5% of diuron emissions are discharged to surface waters. Infiltration, in particular, is therefore a crucial pathway of pollution for soil and groundwater. Measures for source control are proposed to mitigate the leaching of environmentally relevant substances from construction materials.

This dataset includes concentrations of micropollutants (27) and heavy metals (7) for stormwater runoff from different sampling points at two test sites (A and B) in Berlin, Germany. Both sites are new development areas of similar size that were both constructed in 2017 (1 – 1.5 years prior to the start of the monitoring campaign). Composite samples of individual rain events were taken at three sampling points of each test site: façade runoff, roof runoff and corresponding stormwater runoff from the catchment area. Samples were taken as part of the research project BaSaR (www.kompetenz-wasser.de/en/forschung/projekte/basar/) of Kompetenzzentrum Wasser Berlin, Ostschweizer Fachhochschule and Berliner Wasserbetriebe. More information including sampling and analytical methods are detailed in the corresponding journal paper "Emissions from building materials – a thread for the environment?", submitted to the MDPI-journal Water.

The study was financed through the German Environment Agency (Umweltbundesamt, FKZ 3717373280), which is greatly acknowledged. 

Urbanes Niederschlagsabwasser kann durch verschiedene organische und anorganische Stoffe belastet sein, wie Untersuchungen in zwei Berliner Überbauungen und eine begleitende Modellierung klar zeigten. Daher wurden ein Leitfaden sowie Massnahmen-Steckbriefe für Planer und Architekten entwickelt, um die Belastungen an der Quelle oder nachgeschaltet zu reduzieren, bevor sie in Boden und Gewässer gelangen.

The main aim of this study was a survey of micropollutants in stormwater runoff of Berlin (Germany) and its dependence on land-use types. In a one-year monitoring program, event mean concentrations were measured for a set of 106 parameters, including 85 organic micropollutants (e.g., flame retardants, phthalates, pesticides/biocides, polycyclic aromatic hydrocarbons (PAH)), heavy metals and standard parameters. Monitoring points were selected in five catchments of different urban land-use types, and at one urban river. We detected 77 of the 106 parameters at least once in stormwater runoff of the investigated catchment types. On average, stormwater runoff con-tained a mix of 24 µg L-1 organic micropollutants and 1.3 mg L-1 heavy metals. For organic micropol-lutants, concentrations were highest in all catchments for the plasticizer diisodecyl phthalate. Concentrations of all but five parameters showed significant differences among the five land-use types. While major roads were the dominant source of traffic-related substances such as PAH, each of the other land-use types showed the highest concentrations for some substances (e.g., flame retardants in commercial area, pesticides in catchment dominated by one family homes). Comparison with environmental quality standards (EQS) for surface waters shows that 13 micropollutants in storm-water runoff and 8 micropollutants in the receiving river exceeded German quality standards for receiving surface waters during storm events, highlighting the relevance of stormwater inputs for urban surface waters. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Im Rahmen einer etwa zweijährigen Studie wurde für Berlin erstmals das Ausmaß der Belastung von Regenabfluss mit Spurenstoffen durch ein einjähriges Monitoringprogramm in Einzugsgebieten unterschiedlicher Stadt-strukturtypen (Altbau, Neubau, Gewerbe, Einfamilienhäuser, Straßen) untersucht. Insgesamt wurden über 90 volumenproportionale Mischproben auf etwa 100 Spurenstoffe analysiert (z.B. Phthalate, Pestizide/Biozide, Flammschutzmittel, PAK, Schwermetalle), von denen ein Großteil (>70) detektiert wurde. Die höchsten Konzentrationen an organischen Spurenstoffen wurden für Phthalate gefunden (DIDP+DINP: Ø 12 µg/L), während Schwermetalle von Zink dominiert wurden (Ø 950 µg/L). Für die Mehrzahl der Stoffe gab es dabei signifikante Unterschiede zwischen den Stadtstrukturen. In einem Fließgewässer während Regenereignissen genommene Proben zeigen, dass für einige Substanzen (z.B. DEHP, Carbendazim, einige PAK) Umweltqualitätsnormen im Gewässer bei Regen überschritten werden können. Eine Hochrechnung der über das Regen-wasser in die Gewässer gelangenden Spurenstofffrachten für Gesamt-Berlin hat ergeben, dass Frachten regenwasserbürtiger Spurenstoffe in der gleichen Größen-ordnung wie schmutzwasserbürtige Spurenstoffe liegen können.