Bach, L. & Asmund, G. 2013. Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2012. Aarhus University, DCE – Danish Centre for Environment and Energy, 42 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 55. http://www.dmu.dk/Pub/SR55.pdf
This ninth environmental monitoring programme was conducted in Nalunaq area, about 40 km from Nanortalik, South Greenland, from 7 to 13 September 2012. The environmental monitoring programme is conducted to trace and avoid unwanted impacts of the mining industry to the environment. Since the monitoring in 2011, the mining company Angel Mining Gold A/S has continued to break ore in the mine. The gold is recovered by the use of chemical extraction (carbon-in-pulp) with the use of cyanide. Due to the use of cyanide to extract gold from the ore, there is strict control with the outflow of cyanide from the mine to the valley.
Blue mussels, seaweed and sculpins were collected at 4-5 stations in the Kirkespir Bay, Arctic chars were caught in Kirkespir River and lichens, Flavocetraria nivalis, were collected at 23 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.
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 lower in 2012 than in 2007 and 2008 and are comparable to concentrations measured in 2010. The measured elevated element concentrations are supposed to be due to mining activities related to outdoor crushing at the 300 m portal and from gravel road related dust spreading.
The relations between the concentrations of Cu, Cr, As, and Co in the lichens and the perpendicular distance to the gravel road were examined for the period from 2005-12. For all metal concentrations, there is a significant decrease with increasing distance to the road. Elevated levels of Co and As were found at a distance of up to approx. 1300 and 1500 m from the gravel road, respectively, while the Cr and Cu concentrations reached the background levels approx. 750 m from the road.
Elements were measured in the freshwater system of the mining area – from upstream the camp, the water discharge supply from the mining wastewater, through the sedimentation pond and further downstream the Kirkespir River. Both water and sediments showed elevated concentrations of several elements in the mining wastewater discharge compared to upstream concentrations. After the settlement pond only the concentrations of Cu could not meet the water quality criteria. There was however no indications of elevated Cu concentrations or any of the other measured metals in livers of Arctic char.
Kirkespir River runs out in Kirkespir Bay, where blue mussels, seaweed and sculpins were collected. The marine environment was in 2012 only slightly affected by mining activities. While seaweed and mussels were impacted by the outflow of elements by the Kirkespir River and had slightly elevated concentrations of most elements and particularly at the marine stations closest to the estuary, no significantly elevated element concentrations were found in sculpin livers at any of the marine stations.
The environmental impact from spreading of elements on the environment of the Kirkespir Valley and Bay, terrestrial, freshwater and marine, due to mining is considered to be minor and there is no need for further actions to reduce the environmental impact.