HELSINKI, March 22 (Xinhua) -- A high court in Rovaniemi, northern Finland on Thursday sentenced Pekka Pera, founder and original director of Talvivaara mining company, to half a year in prison on probation on account of severe environmental pollution.
Starting in 2015, the lawsuit was considered the most significant environment criminal case in Finland. Two executives of the mining company were fined. A lower court had also fined Pera previously.
The operation in Talvivaara nickel and zinc mine began in Sotkamo, Northern Finland in 2008. It used a water bio-diluting process in separating the ore.
The waste reservoirs were problematic from the start. They overfilled due to rainwater, and contaminated water leaked to the environment. The waste water included metal and gypsum.
Major leaks occurred in 2008, 2010, 2012 and 2013. Researchers from the Helsinki University determined that two adjacent lakes had been badly contaminated and turned into salt waters without any live nature at the bottom.
The prosecution said that problems piled up as the errors were never corrected. The company had misled environment officials during the permit process and given them deficient and faulty information.
The defendants denied the charges and said environmental problems had not been caused by negligence, but the impact of the waste water was unprecedented and the leaks were mere accidents.
The low grade nickel ore was discovered in the 1970s. Traditional mining was deemed unprofitable and the Finnish Outokumpu company sold the mining rights to Pera at the price of one euro in 2003.
Just before a major leak, the Finnish ministry of environment established in 2012 that the surveillance of Talvivaara had been done properly.
Talvivaara company was established in 2003. It ceased to be connected with the mining operation in 2015. Since then, Finnish state majority owned company Terrafame has been running the mining operation.