Tap Water Unsafe to Drink in Svalbard Town Longyearbyen as Permafrost Thaws

Residents of Longyearbyen, a town in Norway's Svalbard archipelago, have been advised to stop drinking tap water after heavy metal contamination was found in it. Scientists tie the pollution to thawing permafrost. The town lies about 1,300 kilometres from the North Pole and is warming five to seven times faster than the global average, The Guardian reports.

Source of the water and what happened

The town gets its drinking water mainly from Isdammen, a dammed lake about 2.5 kilometres long. Rising temperatures have thawed permafrost, exposing rock layers from which heavy metals wash into the lake. Permafrost is ground that stays frozen all year; only its upper layer thaws in summer.

Marjolaine Verret, associate professor of Arctic geology at the University Centre in Svalbard, explains that thawing combined with shale rock containing the mineral pyrite is responsible. When pyrite meets water and oxygen it oxidises and forms acids, which leach out metals. In Longyearbyen the main problem is manganese.

Measures and current situation

The municipality first warned the roughly 2,600 residents last September, when manganese concentration was 25 times above the level recommended by the Norwegian Institute of Public Health – 50 micrograms per litre. Long-term exposure to elevated manganese can cause neurological disorders, especially in children and infants. A tank of free purified water, filtered by a local brewery, was set up near a supermarket.

Manganese levels have since fallen, but earlier this year sulphate and nickel concentrations were found to exceed recommended limits, so the ban on drinking tap water remains in force.

Mayor Terje Aunevik acknowledges widespread dissatisfaction among residents and says the town may need an entirely new water supply system. Options under consideration include a filtration system at the lake and seawater desalination, either as a backup or as the main source. Both would be extremely expensive, and the harsh climate would pose technical challenges.

Verret warns that similar conditions exist elsewhere in the Arctic, for example northern Canada and Alaska, so Longyearbyen could be one of the first such examples.