Norilsk, Russia (CNN)Vasily Ryabinin stands on the banks of the River Daldykan and pushes a long stick into the blood-orange sludge. Raising the stick, he puts a lighter to it and it ignites it like a torch.
"Still burns really well," Ryabinin says. "It's very likely that these puddles are stretching all over the river and will be polluting it for a very long time."
We were a few kilometers from the Siberian city of Norilsk, where six weeks ago a huge fuel tank at a power plant ruptured, spilling thousands of tons of diesel into the river.
Whistleblower sacrificed his job and family's future
The owner of the plant, the Nornickel metals giant, says the spill was quickly contained, and the damage limited. Ryabinin has sacrificed his job and his family's future in Norilsk in an attempt to lift the lid on what environmentalists have called the worst ecological catastrophe in the polar Arctic."