Sci 2020, 3, 5; doi:10.3390/sci2010005 www.mdpi.com/journal/sci Article XRF Quick‐Scan Mapping for Heavy Metal Pollutants in SuDS: A Methodological Approach Guri Venvik 1, * and Floris C. Boogaard 2,3 1 Geological Survey of Norway, P.O. Box 6315 Torgarden, 7491 Trondheim, Norway 2 NoorderRuimte, Centre of Applied Research and Innovation on Area Development, Hanze University of Applied Sciences, Zernikeplein 7, P.O. Box 3037, 9701 DA Groningen, The Netherlands; Floris@noorderruimte.nl 3 Tauw Group, P.O. Box 133, 7400 AC Deventer, The Netherlands * Correspondence: guri.venvik@ngu.no; Tel.: +47‐73904313 Received: 24 November 2019; Accepted: 21 January 2020; First Version Published: 30 January 2020 (doi:10.3390/sci2010005) Abstract: Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle‐bound heavy metals, which are known to often accumulate in the topsoil. In this study, a portable XRF instrument is used to provide in situ spatial characterization of soil pollutants. The method uses portable XRF measurements of heavy metals along profiles with set intervals (1 meter) to cover the swale with cross‐sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In‐Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost‐efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long‐term functioning of the soil‐based SuDS facilities. Keywords: portable X‐ray fluorescence spectrometer (XRF); heavy metals; lead (Pb), zinc (Zn); copper (Cu); topsoil; sustainable urban drainage systems; SuDS; LID; BMPs; WSUD; GI; SCMs 1. Introduction In urban and densely populated areas, surface runoff can carry material residue produced by daily human activity and has been identified as an important pathway for pollutants that enter receiving water bodies [1,2]. Sustainable urban drainage systems (SuDS, also called green infrastructure (GI), best management practices (BMP), low impact development (LID), water sensitive urban design (WSUD), ecosystem‐based adaptation (EbA) and nature‐based solutions (NBS) and more [3]) are constructed to receive, store and infiltrate surface water to restore the groundwater balance and to remove pollutants, such as lead, zinc and copper [4]. An increased pollutant load in urban stormwater degrades water quality, therefore knowledge of the characteristics of the pollutants is needed—vital knowledge that can be incorporated management and maintenance [5]. With climate change, a higher proportion of rainfall will become surface runoff [6], which in turn will result in increased peak flood discharges and subsequently degraded water quality [7].