Environmental scandal at Blausee: Transport entrepreneur faces Bern commercial criminal court
A Bern-based transport entrepreneur is facing court over illegal disposal of contaminated material at the Mitholz quarry. The proceedings are connected with a fish die-off at Blausee.

Trial in Mitholz environmental scandal: Defendant pointed to market pressure
From Wednesday, the head of a Bern transport company must answer to the Bernese commercial criminal court. According to SRF, he is alleged to have illegally disposed of tonnes of contaminated material from washing plants for gravel and concrete at the Mitholz quarry in the Bernese Oberland over a period of years.
The prosecution accuses the man, among other things, of fraud, wilful damage and violations of the Waters Protection Act. He is said to have instructed his drivers to deliver contaminated excavation material not to a regular landfill, but to the Mitholz quarry as well as to other pits in Switzerland. The drivers are also alleged to have forged delivery documents on the instructions of their boss and declared the contaminated material as clean excavation material. The verdict is expected on 10 November; the presumption of innocence applies.
In court, the defendant admitted that he had been aware that the material delivered could sometimes contain "a brick or some concrete here and there". Since gravel was being processed at the quarry anyway, he had not regarded this as a serious problem. When asked about his motive, he answered: he had always also sold material from the quarry and the lorries were not supposed to travel there empty. "We had to compete with market prices," he explained in court.
The Mitholz quarry is not a licensed landfill. Because it is located in a water protection zone, only uncontaminated excavation material may be deposited there. One and a half kilometres downstream is Blausee, known for its trout farm. From 2018 onwards, thousands of trout died there. The owners of Blausee are convinced that the fish die-off is connected to the illegally deposited material — but this connection has not been proven to date.
The matter became public in 2021 through investigations by the SRF programme "Rundschau" and Tamedia newspapers. As early as 2020, it had become known that the Mitholz quarry had previously been used as an illegal landfill — on that occasion for contaminated material from the BLS construction site at the Lötschberg tunnel. The proceedings against BLS were discontinued last year. The Bern state prosecutor's office justified this on the grounds that the responsible persons could not have known that contaminated materials must not be stored at the quarry.
Source: SRF