Bach, L., Olsen, M. & Asmund, G. 2014. Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2013. Aarhus University, DCE – Danish Centre for Environment and Energy, 44 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 97.
This tenth environmental monitoring programme was conducted in the Nalunaq area, about 40 km from Nanortalik, South Greenland, from 27 August to 7 September 2013. The environmental monitoring programme is conducted to discover pollution from the mining industry to the environment. Since the monitoring survey in 2012, the mining company Angel Mining Gold A/S has continued to break ore in the mine. The gold was 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 was 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 char were caught in Kirkespir River, and lichens, Flavocetraria nivalis, were collected at 24 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 analyzed for 12 metals: 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 area at the former deposit of crushed waste rock and the mine and camp area have significantly elevated concentrations of Cu, Cr, As and Co compared to background levels, but compared to previous years, the concentrations are decreasing. This year the metal concentration on lichens from the pier area, which formerly served as a depot for ore, have decreased and are no longer significantly different from background concentrations. Overall the metal impact to the terrestrial environment was lower in 2013 compared to 2012. The elevated element concentrations are due to dust dispersal from gravel road, mining activities related to outdoor crushing at the 300 m portal and waste rock deposition on the mountain.
The concentrations of Cu, Cr, As, and Co in the lichens along the gravel road were examined for the period 2005 to 2013. The concentrations were significantly highest close to the gravel road. Concentrations of As in lichens could be found above the background level until a distance of about 1500 m from the road, while concentrations of Co, Cr and Cu met the background level about 400, 140 and 80 m from the road, respectively.
Metals were measured in the freshwater system of the mining area upstream the camp, at the water discharge of the mining wastewater, in the settlement pond, and further downstream in the Kirkespir River. There were elevated concentrations of several metals in the mining wastewater discharge compared to upstream concentrations. After the settlement pond all concentrations of metals could meet the water quality criteria and no elevated metal concentrations could be found in livers of Arctic char.
Kirkespir River runs out into Kirkespir Bay, where blue mussels, seaweed and sculpins were collected. In 2013, the marine environment was only slightly affected by mining activities. Seaweed and mussels were impacted by the outflow of metals by the Kirkespir River in terms of slightly elevated concentrations of most metals, 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 dispersal of metals from mining is considered to be minor and decreasing and there is no requirement for further actions to reduce the environmental impact.
By November 2013, the mine closed and a local contractor has taken over the clean-up and restoration of the area, which is expected to be completed by summer 2014. With the closure of the mine, it is expected that the element concentration in the environment due to the mining activity will decrease even further. A small increase in dust dispersal can, however, be expected during clean-up and restoration of the landscape in 2013/2014.
Environmental monitoring will continue at least three years after the closure and is currently planned to take place in 2014, 2015 and 2016.