With the beginning of the EU-Project "Protowet" in the year 1996 the Centre for Environmental Research Leipzig-Halle (UFZ) investigate the distribution, mobility and groundwater-transfer of heavy metals and arsenic in River Mulde wetlands nearby Bitterfeld/Wolfen. 278 sediment samples were taken along four representative transects for the analysis of horizontal and vertical pattern of trace elements to build up field stations for the investigation of the seasonal variability of the heavy metal contents and the element speciation in soil- and groundwater. A main component analysis relative to the contents of trace elements in top soil horizons separates two main input sources of the industry of Bitterfeld/Wolfen (Ag, Cr, V, W, Sn) and the industry and mining region of the Ore Mountains in Saxony (As, Cd, Ni, U, Zn). The analysis of the deeper soil horizons reflects the heavy metal input of the industry of Bitterfeld/Wolfen and the two input sources of the River Mulde from Zwickau (U, Ni) and the River Mulde from Freiberg (As, Pb und Cu) in Saxony. A duster analysis represents the horizontal pattern of heavy metals and arsenic. The highest contents were detected in sediment layers of seasonal flooded natural levees in erosion and sedimentation zones beside the river in contrast to lower contaminated, only seasonal flooded backswamp areas and low contaminated, higher elevated floodplain zones. Vertical overbank sediment profiles of the transect II (Spittelwasser) and transect IV (River Mulde/Kleutsch) make it possible to separate younger heavy metal inputs from Bitterfeld/Wolfen in top soil layers (Ag, Cr und Sn) and older inputs from Saxony in deeper soil layers (As, Cd, Cu, Pb, Zn).