Police Investigate Contamination in Lake Constance

Police said authorities were examining the contents of two five-liter (1.3 gallon) canisters found at the bottom of Lake Constance last Wednesday. They confirmed that water samples had revealed a contamination of the water with the weed killer Atrazin and other toxic substances, but emphasized that there had at no time been a danger to drinking water from the lake, which supplies some 4.5 million people.

Last month, the Lake of Constance water supply authorities (BWV) received an anonymous letter threatening to dump pesticides in the lake. On Monday, police said they had a lead on a suspect -- a farmer in the nearby city of Ravensburg who they say may have deposited the canisters in Lake Constance as an act of revenge against the judicial authorities. Around 40 police officers investigated the farmer's property. Officials have ruled out the possibility of a terrorist attack.

Police said that, for tactical reasons, they had not informed the media about the incident immediately.

"We didn't want to alarm the public," said the head of the Lake Constance district authority, Siegfried Tann, adding that police had hoped to catch the perpetrator near the scene of the crime. The police said the writer's only demand was that the general public be informed.

Fearing that more canisters containing toxic substances may have been dumped in the lake, which has an area of over 500 square kilometers (310 square miles), police used underwater cameras to search the area where the two containers were found.

Since the threatening letter was sent, police and suppliers in the state of Baden-Württemberg have tightened their controls on the sales of pesticides. There has been a general ban on the use of the weed killer Atrazin since 1991, although owning it is not forbidden.