On November 1st 1986, Switzerland woke up to a state of emergency. A fire in a building in Schweizerhalle, near Basel, shrouded the entire region in a poisonous veil of thick smoke that billowed from 1,351 tonnes of pesticides and agrochemicals. It remains one of the worst environmental disasters ever to have occurred within Europe's borders.
Fire fighters battled the flames with thousands of cubic metres of water, causing the factory's retention basin to overflow. This in turn led to an estimated 30 tonnes of chemical products leaking into the Rhine, which turned red.
The pollutants destroyed the river’s flora and fauna, with the remains of hundreds of tonnes of fish and other dead animals found in the river in following days. The contamination also affected the surrounding soil and groundwater.
25 years on, a leading expert on the disaster says the area remains polluted. Research published in a new book by Martin Forter claims that Sandoz has failed to adhere to binding agreements with Basel-Landschaft canton aimed at preventing pollution in the groundwater around the site.
Forter told newspaper Badische Zeitung that pollution levels were "five to seven times greater" than the agreed maximum levels.
The researcher said there remained a risk of contamination at a well located just 200 metres away from the site which serves the nearby town of Muttenz.
Although cantonal environmental authorities have not deemed it necessary to decontaminate the site again, they have asked Clariant, the current owner of the site, to draw up a monitoring plan that should be ready by February 2012.
No one at Sandoz management was ever held accountable for the disaster, the cause of which has never been firmly established. Two fire fighters were convicted for ordering that the contaminated water be discharged into the Rhine.