The oil belongs to Norilsk Nickel, the world's largest producer of nickel and palladium. The spill occurred after a huge cistern of a power plant collapsed and the oil sprayed onto the ground and down into the nearby Ambarnaya River.

The company kept quiet

The accident happened last Friday, but it took two full days before the company reported the accident to the local authorities, who first heard about it on social media. An investigation into suspected pollution and negligence has been initiated and the head of the power plant has been arrested.

Accident information has also prompted President Vladimir Putin to react sharply. During a video conference on Wednesday, Putin asked the leadership of Norilsk Nickel why it had taken two days before the authorities were informed.

- Should we be alerted to emergency situations via social media? he said.

The oil has driven 12.5 kilometers from the accident site and colored large parts of the river red. An area of ​​350 square kilometers has been contaminated. According to the World Wildlife Fund (WWF), this is the second worst natural disaster in Russia's history and Greenpeace has compared it to the Exxon Valdez oil spill in 1989.

Hard and expensive to clean up

Several environmental organizations have warned that the magnitude of the accident can make cleaning up very difficult. Oleg Mitvol, former deputy head of the Russian environmental organization Rosprirodnadzor, believes it can take up to 10 years to get the river clean again. It won't be cheap. The bill is expected to land at 100 billion rubles, almost SEK 14 billion.