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No. 20: Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2011

Bach, L., Asmund, G. & Søndergaard, J. 2012. Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2011.  Aarhus University, DCE – Danish Centre for Environment and Energy, 42 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 20. http://www.dmu.dk/Pub/SR20.pdf

 

Summary

This eighth environmental monitoring programme was conducted in the Nalunaq area, about 40 km from Nanortalik, South Greenland, from 2 to 12 September 2011. The environmental monitoring is conducted to trace and avoid unwanted impacts of the mining industry on the environment. Since the monitoring in 2010, the mining company Gold Angel Mining A/S is breaking new ore, but is also carrying previously broken ore with low grade back to the mine with vehicles with limited speed and load capacity. The gold is recovered by the use of chemical extraction (carbon-in-pulp) using cyanide. Due to the use of cyanide to extract gold from the ore, strict control with the outflow of cyanide from the mine to the Kirkespir Valley is performed.

Blue mussels, seaweed and sculpins were collected at 4-5 stations in Kirkespir Bay, Arctic chars were caught in Kirkespir River and lichens, Flavocetraria nivalis, were collected at 20 stations in Kirkespir Valley and around the bay area. Lichens were also transplanted from an unpolluted area (AMIT) to the Kirkespir area. All samples were analysed for 12 elements: arsenic (As), gold (Au), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), nickel (Ni), lead (Pb), selenium (Se) and zinc (Zn). The results were compared with background levels measured in 1998-2001 and with the results of previous monitoring studies.

The marine environment in 2011 was only slightly affected by mining activities. No significantly elevated element concentrations were found in mussels and in sculpin livers while seaweed had slightly elevated concentrations of Cu at all the marine stations, including the reference station. Furthermore, slightly elevated values of Au and Co were found in seaweed.

In the fresh water environment indications of minor elevations of the metals Cd and Pb in livers of Arctic chars were found.

In the terrestrial environment, lichens from the fields at the pier, the depot of crushed waste rock and mine and the camp showed significantly elevated concentrations of Cu, Cr, As and Co compared to background levels as in previous years. The concentrations of metals in the transplanted lichens were however lower in 2011 than in 2007 and 2008 but higher compared to 2010. The increase in 2011 is mainly supposed to be due to mining activities related to outdoor crushing at the 300 m portal, transport of high-grade ore from the depot above the pier back to the mine for mining purposes, and from road dust.

The relations between the concentrations of Cu, Cr, As, and Co in the lichens and the perpendicular distance to the road were examined for the period from 2005-11. For all metal concentrations, there was a significant decrease with increasing distance to the road with the exception of the two most exposed stations, 11-t and 20-t. Elevated levels of As and Co were found at a distance of up to approx. 2000 m from the road, while the Cr concentration reached the background level approx. 1000 m from the road and Cu approx. 500 m from the road.

The described impacts on the environment of the Kirkespir Valley, both terrestrial, freshwater and marine, are considered to be minor, and are generally lower than during the operation in 2004-2009.