Inco Superstack

The Inco Superstack in Sudbury, Ontario, with a height of 380 m (1,247 ft), is the tallest chimney in Canada and the Western hemisphere, and the second tallest freestanding chimney in the world after the GRES-2 Power Station in Kazakhstan. It is also the second tallest freestanding structure of any type in Canada, ranking behind the CN Tower but ahead of First Canadian Place.

It was constructed by Inco Limited in 1972 at an estimated cost of 25 million dollars; from the date of its completion until the GRES-2 chimney was constructed in 1987, it was the world's tallest smokestack. Between the years 1972-75 it was the tallest freestanding structure in Canada.

The Superstack sits atop the largest nickel smelting operation in the world at Inco's Copper Cliff processing facility in the city of Greater Sudbury.

The structure was built to disperse sulphur gases and other byproducts of the smelting process away from the city itself. As a result, these gases can be detected in the atmosphere around Greater Sudbury in a 150 mile radius of the Inco plant. Prior to the construction of the Superstack, the waste gases caused severe ecological damage in the area around Sudbury. This included an almost total loss of native vegetation in some areas, giving the city a reputation as a barren, rocky wasteland.

Construction of the Superstack allowed the city to launch an environmental reclamation plan which has included rehabilitation of water bodies such as Lake Ramsey, and an ambitious regreening plan which has seen over three million new trees planted in the city. In 1992, the city was given an award by the United Nations in honour of its environmental rehabilitation programs. Despite these efforts, much of the environmental damage to the Sudbury area is permanent, particularly to exposed rocky outcrops, which have been dyed jet black by acid rain in a layer which penetrates up to three inches into the once pink-gray granite.

While the Superstack lowered the ground-level pollution in the city, it also dispersed the gases over a much larger area. This led to a slow rise in acidity of lakes in the area, to the point where by the late 1980s up to 7,000 lakes were severely damaged due to acid rain. Starting in the early 1990s, a major construction effort started to dramatically clean the waste gases before pumping them up the Superstack, removing around 90% of the sulphur dioxide. The upgrades were completed in 1994, and emissions from then on are much reduced [ [http://www.inco-sudbury-airquality.com/SO2Emissions.htm Process Overview ] ] . Further reductions in emissions are planned.

ee also

* List of chimneys
* List of tallest freestanding structures in the world

References

External links

* [http://www.mndm.gov.on.ca/mndm/mines/ims/hist_album/pictures/stack_e.jpgPicture from Ontario MNDM site]
* [http://www.emporis.com/en/wm/bu/?id=212441 Emporis listing]
* [http://www.skyscraperpage.com/cities/?buildingID=1511 Skyscraperpage]
* [http://www.inco-sudbury-airquality.com/ Inco Air Quality Site]