Russia declared a state of emergency on Wednesday, five days after a power plant fuel leak in its Arctic region caused 20,000 tonnes of diesel oil to escape into a local river, turning its surface crimson red. The Ambarnaya river, into which the oil has been discharged, is part of a network that flows into the environmentally sensitive Arctic Ocean.

The state-owned TASS news agency reported that the emergency measures were announced within Russia’s Krasnoyarsk Region, located in the vast and sparsely populated Siberian peninsula. The power plant is located near the Region’s Norilsk city, around 3000 km northeast of Moscow.

How did the Oil Spilled?

The thermoelectric power plant at Norilsk is built on permafrost, which has weakened over the years owing to climate change. This caused the pillars that supported the plant’s fuel tank to sink., leading to a loss of containment on May 29. Reports said that around 20,000 tonnes of diesel oil was released into the Ambarnaya river, which has since drifted 12 km on its surface.

Norilsk Nickel, the Russian mining giant that owns the plant, said it had reported the leak in a “timely and proper” way and that the pillars had held the tank in its place “for 30 years without difficulty”.

The conglomerate, which is the world’s leading nickel and palladium producer, has also been blamed for another leak in 2016, when pollutants from its plant leaked into another river in the region. As per an AP report, its factories have made Norilsk one of the most heavily polluted places on Earth.

What has Russia done so far?

The leak, which took place on Friday, came to the notice of the Region’s governor, Alexander Uss, on Sunday. Uss told President Vladimir Putin during a televised videoconference that he became aware of the spill after “alarming information appeared in social media”. Putin, who appeared irate, ordered a probe into the incident.

Boom obstacles were placed in the river, but they were unable to contain the oil because of shallow waters.

So far, three criminal proceedings have been launched, and the head of the power plant has been detained, the TASS report said.

The state of emergency declared on Wednesday would bring in extra forces and federal resources for the clean-up efforts, the Moscow Times reported.

What is the extent of the damage?

Environmentalists have said the river would be difficult to clean, given its shallow waters and remote location, as well as the magnitude of the spill. A World Wildlife Fund speaking to the AFP news agency described this as the second-largest known oil leak in modern Russia’s history in terms of volume.

The Russian chapter of activist group Greenpeace said damages to the Arctic waterways could be at least 6 billion rubles (over $76 million), and has compared the incident to Alaska’s 1989 Exxon Valdez disaster. Its estimate does not include atmospheric damage due to greenhouse gases and soil pollution. In a statement, the NGO said, “The installed buoys will only help collect a small part of the pollution, leading us to say that nearly all the diesel fuel will remain in the environment.”

An environmental oversight agency of the Russian government pegged the overall damage at “several dozen, perhaps hundreds of billions of rubles”, as did a federal fishing agency, the Moscow Times reported.