Navigation

Skiplink Navigation

Main Features

Lonza Chemical firm accused of polluting drinking water

factory and river

Was Lonza careless in its handling of carcinogens near water?

(© KEYSTONE / OLIVIER MAIRE)

Swiss chemical company Lonza has been accused of violating the federal water protection act and of negligence for its role in contaminating drinking water. 

According to the public prosecutor’s office of canton Valais, Lonzaexternal link allowed a carcinogenic solvent to pollute the water of Visp for years but failed to do anything about it. 

+ Lonza’s role in the clean-up of mercury contamination 

In an indictment filed with the district court in Visp, the prosecution says Lonza repeatedly let dangerous substances flow into and near the water. It states that Lonza’s chemical factory in Visp contaminated drinking water with dioxane between 2011 and 2012 and again between 2014 and 2017. 

The 1.4-dioxane solvent is used to make products like paint, varnish, detergent, cosmetics, insecticides and herbicides. High levels – and possibly low ones, too – cause cancer in humans and pets. 

The contamination was unearthed during groundwater monitoring in 2014. Lonza is the only company in the area that uses large quantities of the solvent, points out the public prosecutor. 

Lonza insists that it has neither violated the Federal Act on the Protection of Watersexternal link nor endangered the population and the environment. It points out that when the pollution was discovered in 2014, there were no specific limits on the chemical levels in drinking water, groundwater or industrial wastewater. 

The public prosecutor also criticises canton Valais for simply reacting to known cases of pollution rather than trying to prevent them. When queried by the Swiss News Agency, local authorities said that drinking water was never affected and that the two private wells contaminated with dioxane had been closed temporarily.


SDA/ATS, swissinfo.ch, sm

Neuer Inhalt

Horizontal Line


swissinfo EN

Teaser Join us on Facebook!

Join us on Facebook!

subscription form

Form for signing up for free newsletter.

Sign up for our free newsletters and get the top stories delivered to your inbox.








Click here to see more newsletters