A Russian mining giant admitted that a spill at one of its plants turned a river blood red last week.

Norilsk Nickel, the world’s biggest producer of nickel and palladium, initially denied that its nickel processing factory had leaked industrial waste into the Daldykan river near the Arctic Circle.

The mining company said that, after an investigation, it found “abnormal heavy rain” on Sept. 5 had caused a tailings dam — which holds mining residue and wastewater — to overflow into the river.

 Norilsk Nickel said the area saw roughly 50 percent of its monthly average precipitation in rainfall over the course of 24 hours.

Their statement on twitter

“The overflow of one of the dikes occurred, and water entered Daldykan river,” Norilsk Nickel said in a Sept. 12 statement.

The company claimed the contamination was harmless and said it would work to avoid such incidents in the future.

“Short-term river color staining with iron salts presents no hazards for people and river fauna,” according to the statement.