The Talvivaara polymetallic and uranium mine at Sotkamo in eastern Finland was granted a license to mine nickel in 2006. Talvivaara has since proven itself to be a hazard for water systems on both sides of the watershed.

During only its first couple of years in operation Talvivaara mine has systematically failed to follow its environmental permits, having consistently exceeded its permitted effluent levels, officially polluted four lakes beyond regular usage, and spreads its pollutants to important water courses within a 80 kilometer radius from the mining area.

As of November 2012 Talvivaara has been reported to have involved 1 million cubic meters of contaminated liquid (1,000,000,000 litres). Based on the pond dimensions figures between 1.4 and 3 million m³ have also been estimated. A substantial part of the spill gathered in emergency ponds, which mainly consist of swamp areas. There are major concerns because the safety ponds have leaked, which was discovered and documented by environmentalists; and as the ponds lack any bottom lining, thus are not isolated from regional ground waters. At least 20,000 cubic meters of the spill entered in the northern Oulujoki-waterway. The major leak to the south through the lake Ylä-Lumijärvi in the major East Finland Vuoksi- waterway included at least 200,000 cubic meters of wastewater.

http://www.hs.fi/kulttuuri/art-2000002702648.html