Folldal mines - measures to reduce runoff containing heavy metals
Former mining operations in Folldal lead to acidic and heavy metal-containing water runoff to the river Folla downstream of the mining area. It has been concluded that the water is heavily polluted by metals, which is why there are no fish in the river Folla.
In an instruction from 2003, the Norwegian Environment Agency has given DMF (the Norwegian Directorate of Mining) the following objective for measures against pollution from Folldal mines:
The measure aims to reduce the runoff from the mine area by 60 - 90 percent compared to the survey carried out in 1998. It is a goal that the concentration of copper in Folla at Folshaugmoen is to be reduced to 10 - 15 µg/liter.
Folldal mines as it stands today
Method/result
On behalf of DMF, NGI has been tasked with assessing various alternative measures against mining pollution from Folldal mines to improve the environmental situation in the river Folla, and at the same time, safeguard cultural relics from the mining operation which started in 1748 and closed down in 1993.
Since 2014, NGI has extensively characterized and mapped the acid-forming potential of tailings and mapped groundwater, mine water, surface water, and river sediments at Folldal mines.
NGI has also conducted laboratory tests measuring the effect of various covering solutions and experiments with neutralizing acidic mine water. A proposal for an action plan has been made, with a cost-benefit assessment of various action solutions, where a combination of mine water purification and covering of tailings was assessed as the most relevant measure.
Next, NGI has made a more detailed assessment of the cost-benefit of various solutions covering waste masses.
NGI is also a member of a two-person expert group for DMF, where a comprehensive action plan for Folldal mines was drawn up in 2022, based on, among other things, NGI's previously carried out investigations and assessments.
NGI is now working further on the design of the concrete solution in the comprehensive action plan.
