The goal of the project was to understand the impact of lateral hydraulic connectivity on the pollution patterns in floodplain soils. Floodplain soils were sampled during summer and autumn 2020 on 89 sites along River Elbe following the German Federal Soil Protection and Contaminated Sites Ordinance (12 July 1999) (Bundes-Bodenschutz- und Altlastenverordnung (BBodSchV)). Five subsamples of topsoil (0 – 10 cm) and subsoil (45 – 55 cm) were taken on each 4 m x 4 m plot and combined to one gross sample each.By sieving the dried samples were separated into 12 grain size fractions (2-63 mm, 1-2 mm, 0.63-1 mm, 0.2-0.63 mm, 0.125-0.2 mm, 0.063-0.125 mm, 0.063-2mm, 0.02-0.063 mm, 0.0063-0.02 mm, 0.002-0.0063 mm, 0.002-0.063 mm, <0.002 mm). Further laboratory analyses were carried out following recent DIN standards. Inorganic pollutants (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) were analyzed in the soil fraction <63 µm; organic micro-pollutants (polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticides) in the fraction <2 mm. The analysis of nutrients and additional soil parameters was carried out in the fraction <2 mm and the total sample, respectively. The concentrations of the organic micro-pollutants were converted to the <63 µm fraction to be able to compare samples of different grain size distributions. The concentrations of the inorganic pollutants were converted to the <2 mm fraction for evaluating them according to the limit values defined in the German Federal Soil Protection and Contaminated Sites Ordinance (12 July 1999). Analytic values below the limit of quantification were replaced by the actual limit itself.A pollutant index for both inorganic trace pollutants and organic disruptors was calculated using multiple linear regression obtained by factor analysis without rotation.Additional environmental variables (flood duration, Euclidean distance to the river axis, river stationing) were modeled, computed or queried by GIS within the ElBiota project (https://elbiota.bafg.de).