Langøya is a fascinating island with a special history behind it. Future plans for the island are equally exciting.

Langøya is situated in the Holmestrand Fjord and belongs to the Holmestrand municipality in Vestfold and Telemark. The island consists of limestone from the Silurian geological period, of around 300-400 million years old. Øya is approx. 3 km long and 500 m wide, at its widest point. The area is known for its special flora and fauna, thanks to the chalky soil and a temperature that is slightly higher throughout the year than the average on the mainland.

Limestone extraction

Limestone extraction has been going on for many years, and there are traces of past chalk incineration. 1899 saw the start of industrial limestone extraction for use in cement production on Slemmestad. Langøya was a raw material source right through to 1985, when cement production closed down. Until then, approx. 45 million tonnes of stone were extracted. The result was two craters of 9.3 million cubic metres, under the sea. The stone extraction goes as far down as 40 metres below sea level.

Waste management

After 1985, Langøya became mainly about waste treatment and disposal of waste that was harmful to the environment, as well as disposal of inorganic industrial waste, dug up soil and sediment. From 1994, waste from other countries, in particular Denmark and Sweden, was also brought here.

All hazardous waste received on Langøya is converted and re-used. This is done by turning the waste into stable and environment-friendly building material, which is then used to fill the large craters caused by the hundreds of years of limestone extraction. NOAH’s work on Langøya is therefore part of a large and important rehabilitation project, which is supported by Norwegian authorities.