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Scientists deem CWA threat at Nord Stream 2 negligible

The sea bed around the new Nord Stream 2 pipe line has been surveyed for the environmental risks posed by Chemical Warfare Agents (CWA) dumped in the sea at the end of WW2. The results show the threat to be negligible according to a scientific report from DCE – Danish Centre for Environment and Energy.

The pink diamonds indicate sediment samples taken along the planned route of the Nord Stream 2 gas pipeline, north of Bornholm in the Baltic Sea, by scientists from Aarhus University. (Photo: Orbicon)


Following the end of the Second World War, Germany had stockpiled approximately 65,000 tonnes of CWA munitions. The allied forces ordered all the chemical weapons destroyed during the second half of 1947. The Bornholm basin in the Baltic Sea received a large part of Germanys CWA arsenal with the dumping of approximately 11,000 tonnes active CWA chemical substances into the sea (HELCOM, 1994). 

The primary, and designated, dumping was conducted in a circular area with a radius of three nautical miles, with the centre coordinates at 55oE21"N and 15oE37'02"E covering an area of 99 km2. However, not all CWA was dumped at the designated site, hence a secondary, and more realistic dumpsite is located roughly at 55º10"N to 55º23"N and 15º24"E to 15º55"E, covering 892 km2. The risk zone area where CWA may be encountered covers 9104 km2 around Bornholm. This places the pipeline north of Bornholm within the tertiary dumping area.

The report aimed to assess the risk to the marine environment of detected CWA residues and the added risk associated to the resuspension of sediment particles from construction intervention works at the Nord Stream 2 gas pipeline in the Baltic Sea. Based on chemical analysis of sediment samples and subsequent risk modelling scientists from DCE - Danish Centre for Environment and Energy at Aarhus Universitet found that the added risk represents less than 1 % of the background risk. As the overall background risk is low, it has been concluded that the added marine environmental risk of the detected CWA residues, from intervention works, is negligible.

Read the full report here

For further information contact Hans Sanderson

Mail: hasa@envs.au.dk

Telephone: +4587158632