Climate Change and the European Water Dimension - Agri ...

Areas behind the dikes
broken in 2002
Figure VI.F.2 Overview on the I-TEQ from PCDD/Fs for flooded soils in relation to land
use and the related German guideline values.
The elevated concentrations in the floodplains represent a memory of historic floods
and cannot be attributed to the flooding in 2002. Metallurgic processing in the past
released significant quantities of PCDD/Fs into the Mulde and Saale catchment. The
PCDD/F congener pattern Elbe downstream the inlet of the two tributaries changes
significantly and shows a high similarity with the pattern found in the vicinity of the old
industrial installations there. A similar pattern can be observed in the harbour
sediments of Hamburg as well.
Concern has risen due to the fact that slag heaps from former Uranium mining in the
Mulde catchment were affected by erosion due to the high intensity of precipitation.
However, the post-flood concentrations of 238 U and 226 Ra in the sediments of
Freiberger Mulde were in the range of the typical geogenic background of this region.
The sediments of the Zwickauer Mulde, historically contaminated at a higher level,
showed a significant decrease when compared to past campaigns. Except for local
problems around the Lenkteich and the Plohnbach, where erosion of contaminated
sediments has lead to a local-scale mobilisation of radionuclides, no flood related
contamination was observed.
Release of pathogens during the 2002 event
The threat arising from potential contact with pathogenic microorganisms present in
the muddy residues from the floodwaters in urban areas, especially in buildings and
playgrounds, was another aspect of the project.
Among the species identified through the cultivation on selective media, were
Enterococcus, Enterobacter, Wollbachia, Neisseria, Rickettsia, Legianella,
Citrocacter and E.Coli. Although the colony counts as such were not alarming, a
remarkable resistance against antibiotics was observed. The isolated pathogens from
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Floodplain