"The Inco Superstack is the world's tallest chimney. It was constructed by *nco Limited in 1972 at an estimated cost of 25 million dollars. The Superstack sits atop the largest nickel smelting operation in the world at *nco's "Copper Cliff" processing facility in the city of Greater Sudbury.
The 1257 ft (381 m) structure was built to dispurse sulfur gasses and other byproducts of the smelting process away from the city itself. As a result, these gasses can be detected in the atmosphere around Greater Sudbury in a 150 mile radius of the *nco plant." - taken from nationmaster.com
It should also be pointed out just how close that tailing pond is from a residential area. Though its contents are held back by a retaining wall, this stuff is pretty much right there in some people's backyards.
