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 Re municipality in Vestfold. The island consists of 300-400-million-year-old limestone from the Silurian geological period. Langøya is approximately 3 km long and 500 m at its widest point. Thanks to the chalky soil and a temperature, that is slightly higher throughout the year than the average temperature on the mainland, the island is known for its special flora and fauna.

Limestone extraction

Limestone extraction has been a big part of Langøya´s history. In 1899 limestone was extracted for use in cement production at Slemmestad. Langøya was a raw material source until 1985, when cement production at Slemmestad closed down. At that time, approximately 45 million tons of limestone had been extracted and Langøya was left with two craters with a total volume of 9.3 million cubic meters. The limestone extraction went as far down as 40 meters below sea level.

Waste management

After 1985 Langøya has mainly been about treating and disposing of hazardous inorganic waste, other inorganic industrial waste, excavated soil and sediments. Since 1994, hazardous waste has also been received from other countries, primarily from Denmark and Sweden.

All hazardous waste at Langøya is treated and considered recycled. This is done by chemically converting the hazardous waste into a stable gypsum residue, which is used to replenish the large crates, which were created through more than 100 years of limestone digestion. NOAH’s work at Langøya is therefore considered a major and important rehabilitation work, supported by Norwegian authorities.