Longyearbyen keeps tap-water ban for 2,600 residents

Longyearbyen lokalstyre has kept a do-not-drink advisory for 2,600 residents after heavy metals exceeded drinking-water limits, The Guardian reported on Oct. 19.

The case matters beyond Norway because Longyearbyen is warming at five to seven times the global average, with autumn temperatures rising by as much as 4 degrees Celsius a decade, the article said.

The town, in Norway’s Svalbard archipelago and about 800 miles from the north pole, draws its main supply from Isdammen, a dammed lake about 1.5 miles, or 2.5 kilometers, long.

Researchers cited by The Guardian linked the contamination to thawing permafrost and local geology. Permafrost is ground that stays frozen through the year, except for a surface layer that thaws seasonally.

“The combination of the thawing permafrost and the shale bedrock, which contains a mineral called pyrite, or fool’s gold, is causing contamination of its water supply,” Marjolaine Verret, a permafrost expert and associate professor in Arctic geology at the University Centre in Svalbard, told The Guardian.

Verret said pyrite can oxidise when exposed to water and oxygen, producing acidity. “The acid produced can now leach heavy metals from these rocks into the waterways. The issue we’ve been having here in Longyearbyen is manganese, but other contaminants can be leached out from the rocks.”

Residents were first warned in September 2025, after manganese in the supply was found at 25 times the 50 micrograms per litre recommended by the Norwegian Institute of Public Health, according to The Guardian. Mayor Terje Aunevik said water quality had long been affected by sediment, but manganese levels had “gone ballistic”.

Emergency measures included a central tank of free purified water, filtered by the local brewery, where residents could refill containers at a supermarket. The municipality also opened an investigation into water quality.

Manganese levels have since declined, but sulphate and nickel were found earlier this year above recommended drinking-water limits, so the advisory remains. Aunevik said manganese levels were “not dangerous”, while adding that government guidelines had to be followed.

The Guardian reported that prolonged exposure to high manganese levels can cause neurological problems, especially for children and infants. The article did not give current readings for sulphate or nickel, and the durability of the town’s temporary arrangements remains unclear.

Scientists cited by the paper said Longyearbyen may offer a warning for other Arctic settlements where similar geology meets thawing frozen ground. “These ingredients [bedrock rich in pyrite and heavy metals] and thawing permafrost are present in other parts of the Arctic so this could be a first example of how climate change can impact freshwater, for example in northern Canada and Alaska,” Verret said.

Aunevik said a “completely new water mains supply” may be required. Options under consideration include adding filtration to Isdammen and using desalination as backup, or making desalination the main system, both of which he described as extremely expensive and technically difficult in Svalbard’s cold conditions.

Source: news article, The Guardian, Oct. 19, 2026.