Pollution tests of Berlin waters sediments are not part of the routine measurement program of the Berlin Environmental Department. The measuring results evaluated here are based on special investigations regarding impacts of heavy metals or chlorinated hydrocarbons.
The heavy metal contamination of water sediments was investigated by Pachur and Ahrens from the Institute for Geographic Sciences of the Free University of Berlin. This research project of the Federal Ministry for Research and Technology and the Berlin Environmental Department was conducted in 1990 and 1991. A further sediment study was conducted by the Fechter Engineering Office in commission of the Berlin Department of Urban Development and Environmental Protection..
The heavy metal concentrations in Berlin water sediments depicted in these maps give information for the water sections of
- the Spree and the Dahme, based on Fechter’s analysis data on 37 mud claw samples taken in 1991. They give information on heavy metal impacts in the upper sediment layer, 0 to a maximum depth of 40 cm.
- the Havel waters and the Teltow canal, based on analysis data determined by Pachur and Ahrens in 48 frozen-core bore samples performed in 1991.
The frozen-core bore method employed by Pachur and Ahrens enables a depth-appropriate removal of up to 4 meters of sediment. The frozen-core bore samples are divided by hot-wire into single sections of 5 or 10 cm length. The division of individual bore cores into sections of a few centimeters enhances the detection of horizon-specific geo-accumulations of heavy metals, as well as the allocation of their chronological deposition (cesium determination). One thousand eight hundred individual samples of 6 eco-toxilogical heavy metals (copper, zinc, lead, cadmium, chromium and nickel) were analyzed by atomic emissions spectrometer (ICP-AES) measurements.
Recent sediments were divided into 9 zones for chronological definition. The zones before 1880 show heavy metal concentrations that – with the exception of inputs at local points – lie within the range of natural impacts (geochemical background) uninfluenced by civilization. The zones from 1900 to 1990 were defined in view of increasing anthropogenic influences as accumulation zones and their heavy metal concentrations were used for evaluation of sediment contaminations (average value of accumulation zones). The zone from 1880 to 1900 can be characterized as a transitional zone. It can be disregarded because of its low levels and is not included here in average value calculations. The accumulation depth in sediments of the individual measuring points ranges from 25 cm (Havel, Höhe Quastenhorn) to 235 cm (Stössensee) (see = lake).
Tests for DDT, Lindane and PCB concentrations in sediments, as well as DDT and PCB impacts in eels were conducted in commission of the Berlin Office of Fisheries from 1989 to 1992. Sediment samples were taken by mud claw.