Longyearbyen keeps tap-water ban as thawing permafrost brings metals into its supply
Residents of Longyearbyen, Norway, have been told not to drink tap water after heavy metals entered the town’s main source, Isdammen lake. Researchers quoted by The Guardian link the contamination to thawing permafrost exposing pyrite-rich rock; manganese levels reached 25 times the recommended limit, and later tests found sulphate and nickel above limits.
Bottom line — The ban remains in place while Longyearbyen weighs costly filtration or desalination options, according to mayor Terje Aunevik.
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The Guardian reported that the town first alerted its 2,600 residents in September 2025.
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The Norwegian Institute of Public Health recommends a manganese limit of 50 micrograms per litre, the Guardian reported.
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Arctic geology expert Marjolaine Verret told the Guardian that pyrite reacting with water and oxygen produces acidity that can release metals from rock.
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Authorities provided a tank of free purified water at a local supermarket; the town’s brewery helped filter the supply, according to the Guardian.
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Aunevik told the Guardian that a new water mains supply may be needed; options include filtering Isdammen or using desalination as backup.
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Verret warned the Guardian that similar combinations of thawing permafrost and metal-bearing rock exist elsewhere in the Arctic, including northern Canada and Alaska.