Climate change has caused permafrost to thaw and leak heavy metals, leaving a Norwegian city unable to drink its tap water, the British daily The Guardian reported.

Residents of Longyearbyen, the largest settlement in Norway's Svalbard archipelago, have been told not to drink their tap water due to heavy metal contamination linked to the melting permafrost.

Longyearbyen residents rely for their primary drinking water supply on a 2.5-kilometer-long closed basin known as the "Ice Pond."

However, rising temperatures have thawed the permafrost and exposed fresh bedrock, causing metallic elements to flow into the lake.

Located 1,287 kilometers from the North Pole, Longyearbyen has been warming at a rate 5 to 7 times the global average, with autumn temperatures rising by up to 4 degrees Celsius (°F) every decade.

Marzolene Vicar, an arctic geology associate professor and permafrost expert at the University Centre in Svalbard, explained that "the combination of permafrost thawing and the geological characteristics of shale bedrock containing pyrite is causing the water supply contamination."

Professor Vicar explained that when pyrite comes into contact with water and oxygen, it oxidizes and becomes acidic.

"The acidic substances generated this way dissolve heavy metals in the rocks and cause them to flow into waterways," she said, adding that "while manganese is becoming an issue in Longyearbyen, other pollutants can also leach from the rocks."

The local government of Longyearbyen first issued a warning to its 2,600 residents in September of last year after manganese concentrations in the water supply were found to be 25 times higher than the Norwegian Institute of Public Health's threshold of 50 micrograms per liter.

At the time, Longyearbyen Mayor Terje Aunvik expressed concern that while the water quality had long been poor due to sediment, the manganese concentration had "increased explosively."

Long-term exposure to high concentrations of manganese can cause neurological problems in children and infants.

In response, authorities took temporary measures, providing purified drinking water from a local brewery in a central tank for residents to use.

Although manganese concentrations subsequently dropped, the tap water ban remains in place as sulfate and nickel concentrations were found to exceed recommended drinking water standards early this year.

Mayor Aunvik, who ordered the water quality investigation, said that the water supply system may need to be completely rebuilt.

Options under review include installing a filtration system at the Ice Pond and keeping a desalination facility as a backup, or conversely, utilizing a desalination plant as the primary supply source.

Mayor Aunvik noted that either approach would be costly and involve technical challenges due to Svalbard's extreme temperatures, where water temperatures frequently drop below freezing.

"In Norway, where people have always taken it for granted that they can drink tap water, it is not easy to accept having to haul water manually as we do now," he said, adding that "other small communities should also think about preemptive measures in preparation for the possibility of such events occurring in their drinking water sources."

Scientists have warned that the water contamination in Longyearbyen could be a precursor to what Arctic communities will face in the future.

Professor Vicar said, "The conditions of bedrock rich in pyrite and heavy metals, along with permafrost thawing, exist in other Arctic regions as well," and added, "This case may be an early glimpse of how climate change could impact fresh water in northern Canada or Alaska."
 
(Photo courtesy of the Korea Polar Research Institute, Yonhap News)