Photo: JoachimKohler-HB·CC BY-SA 4.0· Wikimedia Commons
Islands / Holmestrand / Langøya
Island in the Holmestrandfjord with a long industrial history: limestone quarried here from the 1650s, large-scale extraction from 1899 (47 million tonnes taken out, operations running until 1985). Since 1993 a landfill for inorganic hazardous waste, run by NOAH.
Just off Holmestrand lies Langøya, the industrial island with the open crater landscape and NOAH's plant. The huge terraced hollow in the middle of the island is the quarry that supplied Norway with limestone for cement for almost a century. That same hole is now being filled with treated hazardous waste. This is not an island you go ashore on.
Industrial site (NOAH) – no public access.
No scheduled boat comes here. You will have to find the nearest public quay yourself, and the rest is your own boat or a kayak. Check the wind and wave forecast before you set out; the open stretches in the outer fjord turn unpleasant in a fresh breeze.
The first limestone came out of here in the 1650s, with several lime kilns in operation. In 1737 the works were sold to the Danish crown. Modern extraction began in 1899: Christiania Portland Cementfabrik (CPC) bought a parcel in 1895 and the rest of the island in 1899, apart from a small naval area the company acquired in 1937.
At its peak the quarry produced around 180,000 tonnes of limestone a year. Drilling was done by hand until 1913, when compressed air arrived; electric operation followed from 1922. From 1925 the stone crushing was moved from Slemmestad to Langøya, and from 1931 unusable rock was crushed separately and sold as aggregate. Up to 24 families, around 120 people, lived on the island. In 1960 a school boat carried 16 children in to Holmestrand. A narrow-gauge railway ran across the island.
All told, some 45–47 million tonnes of limestone were removed. The quarry floor reached 45 metres below sea level, close to ten million cubic metres of it under the waterline. When Norcem stopped cement production at Slemmestad in 1985, the basis for the operation went with it. Norcem sold Langøya to NOAH in 1993. The island is owned today by Bjørn Rune Gjelsten through his holding company.
In the middle of all this industry, a nature reserve of 21.2 hectares (212 dekar) (21.2 hectares) was established in 1988, along the east coast and at both ends of the island. It protects fossil-bearing rock and the vegetation that grows on it, and has been home to a family of red foxes.
NOAH runs a treatment plant for inorganic hazardous waste on Langøya. The main streams are spent acid from Norwegian industry and fly ash from incineration plants, waste from around 70 industrial companies. It is treated chemically into a filter cake with the environmentally hazardous properties much reduced, and the material is used to fill the old limestone quarries.
NOAH has a long-term plan to return the island to nature once the quarries are full: open limestone grassland, a species-rich and endangered habitat type, along with walking paths, cabins, a marina and a sculpture park on the northern part. The vision is Langøya as a recreation island in the Oslofjord. Until then it stays a closed industrial site with no public access.
Langøya is an active industrial site operated by NOAH. There is no public access and no quay open to visitors, and landing is not permitted. Keep well clear in a boat. No ferry service exists for the public.
47 million tonnes of stone out of a single island. The quarry floor sits 45 metres below sea level; without constant pumping, half the island would be a lake below sea level.
The same limestone that went into Norwegian buildings as cement has left a hole that now takes the country's hazardous waste. The island went from supplying raw material to receiving the remains.
Around 120 people lived here at the peak, with their own school boat. Look for traces of workers' housing and quays in what is now the plant area.
NOAH's plan is for the industrial island to end up as open limestone grassland, sculpture park and marina on top of the old quarry. Whether it turns out that way is for a later generation on the fjord to find out.
Oslo Sea Experience passes Langøya on its private fjord trips from Tjuvholmen.
The Norwegian version notes which facts were taken from each source: Langøya på norsk.