By Polina Devitt
MOSCOW (Reuters) - A spill of waste originating from a metallurgical plant in Russia that turned a river blood-red posed no threat to people or wildlife, an executive at the plant's operator said.
Pictures of the crimson water in the Daldykan river, in the Arctic Circle, quickly went viral over social media, and green campaigners said the incident highlighted how industrial development posed a risk to the environment.
Sergey Dyachenko, Chief Operating Officer of Nornickel, formerly known as Norilsk Nickel, which operates the plant, said the red color was caused by iron salts, a waste product from production at the plant, although it can also occur naturally.
"There is no danger for fish and people," Dyachenko told the Reuters Investment Summit at the Reuters office in Moscow. "We hope that it will not happen in future."
Russian state environmental watchdog Rosprirodnadzor told Reuters it was still conducting checks into the incident and would reach conclusions about the possible damage once test results are ready after Sept. 19.
Alexei Kiselyov, an official at Greenpeace Russia, said iron salts are a mildly toxic reagent and it was impossible to say if there was damage to local fauna without investigating the site.
"The results of the tests are needed," he said.
Dyachenko said the company had been replacing several kilometers of aging pipe which carries waste -- known as tailings -- from the firm's plant to a reservoir where waste is stored.
At the start of this month, workers were fitting the final section of a new pipe. Before connecting it, they injected water into the pipeline to clean it out.
They built a temporary dike to contain any leakage, but the work coincided with unusually heavy rain last week which caused the dike to overflow, allowing water with iron salts to enter the river, turning it bright red, Dyachenko said.
As of Sept. 8, pictures circulated by Greenpeace showed that the river appeared to have returned to its normal color, although ground around it was still red.
"Now the company will be replacing and cleaning up the soil," Dyachenko told Reuters.
More than 80 years ago, prisoners from Stalin's labor camps built the first metal smelter in Norilsk city, where temperatures can drop to 55 degrees Celsius below zero (-67 degrees Fahrenheit). The city has acquired a reputation as one of the most polluted settlements in the world.
Nornickel says it has been implementing a program to improve the ecology of the city and its surroundings since 2103. The replacement of the tailings pipeline was completed at the start of this week, Dyachenko said.
"Today in effect, Nornickel has completed a major project which will draw a line under all the historical pollution incidents," Dyachenko said, adding the new pipeline had a polyethylene lining which would prevent all leaks.
(Reporting by Polina Devitt, Diana Asonova, Katya Golubkova, Christian Lowe, Anastasia Lyrchikova and Svetlana Burmistrova; editing by Peter Graff)