Dioxin in the Elbe river basin: policy and science under the water framework directive 2000-2015 and toward 2021

Abstract

A critical review of the last 25 years of dioxin policy in the Elbe river catchment is presented along seven main theses of the River Basin Community (RBC)-Elbe background document "Pollutants" for the Management Plan 2016-2021. In this period, polychlorinated dibenzodioxins/-furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) will play a major role: (i) as new priority substances for which environmental quality standards (EQSs) need to be derived (Directive 2013/39/EC); (ii) in the search for innovative solutions in sediment remediation (i.e., respecting the influence of mechanical processes; Flood Risk Directive 2007/60/EC); and (iii) as indicators at the land-sea interface (Marine Strategy Framework Directive 2008/56/EC). In the Elbe river catchment, aspects of policy and science are closely connected, which became particularly obvious in a classic example of dioxin hot spot contamination, the case of the Spittelwasser creek. Here, the "source-first principle" of the first cycle of the European Water Framework Directive (WFD) had to be confirmed in a controversy on the dioxin hot spots with Saxony-Anhalt's Agency for Contaminated Sites (LAF). At the Spittelwasser site, the move from "inside the creek" to "along the river banks" goes parallel to a general paradigm shift in retrospective risk assessment frameworks and remediation techniques for organic chemicals (Ortega-Calvo et al. 2015). With respect to dioxin, large-scale stabilization applying activated carbon additions is particularly promising. Another important aspect is the assessment of the ecotoxicology of dioxins and dl- PCBs in context of sediment mobility and flood risk assessment, which has been studied in the project framework FloodSearch. Currently, the quality goals of the WFD to reach a "good chemical status" are not met in many catchment areas because substances such as mercury do and others probably will (PCDD/Fs and dl-PCB) exceed biota-EQS values catchment area-wide. So far, relating biota-EQS values to sediment-EQSs is not possible. To overcome these limitations, the DioRAMA project was initiated, which has led to improved approaches for the assessment of dioxin-contaminated sediment using in vitro bioassays and to a robust dataset on the interrelation between dioxins and dioxin-like compounds in sediments and biota.

Keywords: Activated carbon; Biota-EQS; Bitterfeld region; Chemical status; Dredged materials; Flood risks; Marine strategy; NGOs; RBC Elbe; Sediment management concept.

Fig. 1

Radiometric map combining the concentration data [the last seven intervals—yellow to red—correspond to 2000–6000 ng/kg TEQ] in their areal distribution in Spittelwasser creek bank sediments or fluvisols (Tauw Soil Newsletter from July 2014 [20]) and the information on areal dioxin loads within four different zones of the Spittelwasser site (small table left below shows size of the zones [in hectares] and the respective loads [in kg TEQ WHO-2005]; Jacobs et al. 2013 [19]). The map of Jacobs [20] was slightly edited (legend, size)

Fig. 2

Scheme of the development of an integrated remediation concept for large-scale historical sediment contamination, Spittelwasser in the Bitterfeld District, Germany. Time scale is the stepwise implementation of the EU Water Framework Directive (Anonymous 2000a [1]. Left side “prerequisites”: (i) feasibility study from July 1993 (Anonymous 1993 [39]), (ii) Consoil2000 case study comparison (ConSoil2000 2000b [19, 61]). *In situ processes 2002–2010 (Förstner and Salomons 2010 [66])