Russian officials are investigating mining company Nornickel for pumping waste water from one of its processing plants into nearby Arctic countryside.

Russian newspaper Novaya Gazeta released a video of industrial wastewater flowing through streams that feed into a local lake. Both the newspaper and Greenpeace claim the water contains heavy metals such as nickel, cobalt, and copper.

Norinickel says that it has suspended staff involved in the violation.

This marks the second environmental controversy that Nornickel has seen in a month, after the operator admitted pumping wastewater from its Talnakh enrichment plant near Norilsk, north of the Arctic Circle, in the Krasnoyarsk region.