Beuel · Due to a cyanide find at the biotope building works at the Villicher Bach the German train company (Deutsche Bahn) has stopped the construction for now. There was no cyanide found in the drinking water though, according to the water supplier.
Since the end of August, the works at the biotope at the Villicher Bach have been halted. The reason - „disappointed and devastating“ for the Deutsche Bahn -: during the digging the workers have found „strangely blue-coloured“ earth. The expert examination confirmed: The ground is contaminated with cyanide. The DB reported the poison find to the authorities at the Bonn city council immediately. The location of the poison us about 100 meters towards the western side of the motorway underpass (A59) and therefore in the water protection area of the Meindorf water works.
The city council informed the water supplier Wahnbachtalsperrenverband (WTV) and promised to report any further examination results immediately. „We are regurlarly controlling water in the Meindorf wells and twice annually get the water checked for cyanide by an independent lab, the hygiene institute Bonn. There have been no signs of cyanide in all the three wells or the water works Sankt Augustin-Meindorf for years“, explained WTV director Norbert Eckschlag. The nearest drinking water well is the one in Meindorf, which is about 1.5 km away from the location of the recent find.
The WTV plans to intensively analyse the result to initiate potentially necessary measures in their plants. Also - unrelated to the results - the regular checks of the water in regard to cyanide will be intensified.
Stream to be turned into near-natural water
„After the building works began, it became apparent that below the stream bed a layer of grass grid stones and garden foil with about 20 centimeter of black earth masses underneath them“, said Marc Hoffmann, vice spokesperson of Bonn city council. Because those masses weren’t noticed before, the expert team involved demanded an analysis. „During that analysis a concentration of 190 microgram of Cyanide per kilogram were found“, Hoffmann said.
In consequence the building works were halted and the local environmental authority was notified. The aim of the works is to change the stream into a near-natural water. The Deutsche Bahn has commissioned the work as an ecological compensatory measure for the building of the S 13 extension between Troisdorf and Oberkassel.
On August 22, a (ballot) meeting between the local environmental authority, the DB network and the expert concluded in new examinations along the stream, which will influence decisions on further steps to be taken. On August 27 the DB network reported singular black spots of earth along the stream. It was decided to examine the stream in 200-meter intervals. The results of the examinations along the stream are expected in the next few days. The part of the stream is now fenced off. The stream bed does not need to be secured against water as it is currently dried.
The local environmental authority has researched a possible explanation for the cyanide concentration. The affected earth masses in the area must have been put down during the last development in the 1970s. „Once the results of latest probes are available, the further work at the Vilicher Bach will be decided on. We are expecting the first results in the next few days and will decide together with Bonn city council on the next steps“, explained the DB spokesperson when interviewed by the GA.
(Original text: Holger Willcke / Translation: Mareike Graepel)