90 kilometers east from Oslo is the location of Notodden with a approximate population of 12 000 near the lake of Heddalsvatnet. The southeastern part of Notodden called Jernverkstomt was home to ironworks on an area of 50 000 m2 next to the river Tinnelva. Today the area is used as a temporary storage for construction waste and a parking lot – the entire area requires revitalization.
At the location of Jernverkstomt, historical maps from 1904 and 1910 show a large submerged area with an additional island right next to the river Tinnelva. With the construction of a crude iron factory factory at the beginning of the 20th century the area was dried out and the island connected to land. Factory, operated by Tinfos Jernverk AS, produced crude iron until 1927, after which it was reoriented to ferroalloys (ferrosilicon and ferrochromium) and silica manganese alloys. In 1963 the factory was expanded with gas washing facilities for ovens, and the treatment of waste water started in 1974. Tinfos Jernverk AS also operated a factory of carbide (Notodden Calsiumkarbidfabrikk) east from Jernverkstomt which operated from 1900 to 1952. Ironworks were closed in 1986, leaving behind large amounts of waste in the form of byproducts from iron, ferroalloy and carbide production.
Tinfos Jernverk AS Notodden – Source: municipality of Notodden
At the location of the ex-ironworks in Jernverkstomt, research on environmental pollution was performed. It was concluded that there are high concentrations of carbide and cyanide, large amounts of slags containing chrome, zinc, cadmium, arsenic, nickel and other metals, PAH compounds, and also construction waste deposited from the closing of the factory. Pollution was even found in lower, sand and gravel, layers of the ground – suggesting spreading to the local environment. As a part of revitalization efforts, the removal of toxic and dangerous materials is needed.