Lonza completes major mercury soil remediation in Upper Valais

Lonza is nearing the completion of a decade-long soil remediation project in Upper Valais, Switzerland, aimed at removing mercury contamination caused by the pharmaceutical supplier. Between Raron, Niedergesteln, and Visp, approximately 3.5 tons of mercury have been removed from roughly 170,000 square meters of land.

The pollution was first discovered in 2010 during the construction of the A9 motorway. Investigations revealed that Lonza had discharged mercury-containing wastewater into the Rhone via the Grossgrundkanal for decades, leading to contaminated sediments spreading onto gardens and agricultural areas.

The remediation process involved excavating 160,000 tons of contaminated soil and replacing it with clean earth. This included over 100,000 square meters of residential areas and 60,000 square meters of agricultural land. The total cost of the project is approximately 51 million Swiss francs, with Lonza covering 93.5 percent (47.5 million francs) of the expenses. The Canton of Valais contributed 2 million francs, while affected municipalities provided 1.5 million francs.