Sources and pathways of biocides and their transformation products in urban storm water infrastructure of a 2 ha urban district

Abstract. Biocides used in film protection products leaching from facades are known to be a potential threat the environment. This study identifies individual sources and entry pathways small-scale urban area. We investigate emissions of commonly biocides (terbutryn, diuron, octylisothiazolinone – OIT) some their transformation (TPs; diuron-desmethyl, terbumeton, terbuthylazine-2-hydroxy, terbutryn-desethyl) 2 ha residential area 13 years after construction has ended. Sampling utilizes existing water infrastructure representative for decentralized storm management central northern Europe applies two-step approach (a) determine occurrence above quality limits (i.e., predicted no-effect concentration, PNEC) (b) identify source areas characterize into surface groundwater. Monitoring focuses on analysis selected TPs by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS) samples taken facades, rainwater pipes, drainage, infiltration systems. In standing swale, we found high concentrations diuron (174 ng L?1) terbutryn (40 PNEC water. confirmed expected sources, i.e., facades. rain downpipes flat roofs identified additional all two one TP diuron. Diuron were three drainage pipes representing different biocides. pipe collecting road runoff, only diuron-desmethyl terbutryn-desethyl detected. other infiltrated through soil, terbuthylazine-2-hydroxy was additionally One soil concentration showed highest its (terbutryn-desethyl terbuthylazine-2-hydroxy). suggests terbutryn. The applied determined biocide TPs. contributes expanding knowledge distribution and, thus, eventually towards reducing emissions.