Norilsk

The first nickel matte was produced at Norilsk in 1942. Since then the smelters have released large amounts of sulphur dioxide: about 1.9 million tonnes a year, or 1.9% of world emissions, according to figures given by Wikipedia for 2020. Metals fall out with the gas; the Blacksmith Institute (now Pure Earth) listed the city among the ten most polluted places on Earth, citing cadmium, copper, lead, nickel, arsenic, selenium and zinc.

The old nickel smelter, inside the city, was closed in June 2016: it emitted 380,000 tonnes of sulphur dioxide a year, a quarter of the city's total. In the same year, after heavy rain, a filtration pond at the Nadezhda plant overflowed and the Daldykan River turned red.

On 29 May 2020 tank no. 5 at a thermal power plant belonging to the group failed: 21,000 m³ of diesel (17,500 tonnes) went into the soil and into the Daldykan and Ambarnaya rivers, threatening Lake Pyasino. Corrosion of the tank bottom and foundation failure linked to thawing permafrost are given as causes. Booms were laid across the Ambarnaya by 4 June.