The fuel was a reserve used as a backup for the main gas supply to a power plant. The storage tank was built on permafrost, which, according to a statement by the company, could possibly have melted and become unstable due to climate change. An area of 350 square kilometers (135 square miles) was contaminated and it is proving difficult to clean up the area because there are no roads and the river is too shallow for boats and barges. Oleg Mitvol, former deputy head of Rosprirodnadzor, estimated that the clean-up would cost about 100 billion rubles (US$1.5 billion) and take 5–10 years. Vice-speaker of the Taymyr Duma Sergey Sizonenko noted that about 700 of Taymyr's indigenous people live in the affected area. As a result of the proceedings, Norilsk Nickel was obliged to pay a fine of 146 billion rubles, which went into the federal budget of the Russian Federation, rather than the budget of the municipality. On August 26, 2021, the head of the Ministry of Emergency Situations of the Russian Federation Alexander Chupriyan announced that clean-up work was complete. Water At the beginning of 2020, 43 water treatment facilities were operational in Norilsk. The system is constantly being upgraded. The modernization work is partly funded by Norilsk Nickel. Economy MMC Norilsk Nickel (formerly the Norilsk Mining and Metallurgical Combine), a mining company, is the principal employer in the Norilsk area. Norilsk is a major center of non-ferrous metallurgy; the following non-ferrous metals are mined here: copper, nickel, cobalt; precious metals: palladium, osmium, platinum, gold, silver, iridium, rhodium, ruthenium; by-products: technical sulfur, metallic selenium and tellurium, sulfuric acid. The company produces 35% of the world's palladium, 25% of its platinum, 20% of its nickel, 20% of its rhodium, and 10% of its cobalt. In Russia, 96% of nickel, 95% of cobalt, and 55% of copper is produced by Norilsk Nickel. In 2007 the total volume of commodities produced and services carried out by the company in various manufacturing industries amounted to 321.5 billion rubles. In 2021 Norilsk Nickel's net profit increased by 92% to $6.974 billion. The Norilsk industrial region has all the necessary infrastructure for the production of non-ferrous metals: electric power, hydropower, industrial construction and building material production, and repair and service enterprises. Energy is supplied from the Norilsk CHPP-1, CHPP-2, and CHPP-3 combined cycle power plants, which are located in different parts of the city