Aarhus University Seal / Aarhus Universitets segl

No. 230: A chemical environmental screening study at the former Qullissat coal mine, West Greenland in 2015

Søndergaard J, Wegeberg S, Boertmann D, Bach L, Lassen P, Clausen DS, Mosbech A (2017). A chemical environmental screening study at the former Qullissat coal mine, West Greenland in 2015. Aarhus University, DCE – Danish Centre for Environment and Energy, 50 pp. Scientific Report from DCE – Danish Centre for Environment and Energy No. 230. http://dce2.au.dk/pub/SR230.pdf 

Summary  

The Qullissat Coal Mine on the Disko Island in West Greenland operated be-tween 1924 and 1972. During this period, a total of 570,000 tons of coal was produced. The mining activity at Qullissat culminated during the 1960s with 30,000 tons of coal produced annually and the Qullissat mining town had a population of up to 1,400 people. In 1972, the mine was closed and the mining town was completely abandoned due to financial reasons. No clean-up was performed and remains of infrastructure, buildings, materials and coal residue are still (in 2015) present at the mine site.  

DCE (formerly DMU and before that Grønlands Miljøundersøgelser) has monitored the environmental status of a number of old mining sites in Greenland for decades. These mining sites include closed mines from the last century with a bad environmental status at the time of closure (e.g. Johansen et al. 2008 & 2010). The monitoring studies are now done in a collaboration be-tween the Greenland Institute of Natural Resources (GINR) and DCE. The objective of the studies are twofold: partly to monitor the environment to keep the public and authorities informed of the environmental status and recovery, and partly through research to increase our knowledge about geochemical and toxicological processes in arctic mining areas. The aim is to learn how to secure minimal environmental impact at future new mine sites in Greenland.  

This study is the first to investigate the environment at Qullissat. The study was conducted by DCE in connection with background studies for a Strategic Environmental Impact Assessment for the Disko-Nuusuaq area (Wegeberg & Boertmann 2016). The study is considered a screening study with the aim to identify possible significant pollution sources originating from remains at the mine site and mining town. Also, the study investigates the opportunities for studying effects of chronic exposure to e.g. PAHs (Polycyclic Aromatic Hydrocarbons, i.e. oil compounds) or other potential pollutants in the area.  

During the study, a range of environmental samples was collected during Au-gust 2015 by DCE. Samples included surface soil, freshwater, lichens and marine sediment collected in the tidal zone. Seaweed and blue mussel, which are normally included in DCE’s environmental monitoring programmes in Greenland, were not present in the tidal zone at this site and could therefore not be collected. Most samples were collected near the mine site and some samples were collected near the Qullissat mining town situated approximately 5 km to the north of the mine.  

All environmental samples were analysed for 63 elements (such as heavy metals, rare earth metals etc.) and selected samples of surface soil and sediment were analysed for a total of 29 PAH compounds at DCE’s accredited laboratory in Roskilde, Denmark.  

Surface soil analyses from the Qullissat mine site showed that elevated levels of some heavy metals, especially lead, as well as PAH compounds could be found associated with ochre precipitates and coal residues, respectively. Consequently, the main focus was on heavy metals and PAHs as potential sources of contamination from the site, which is in line with previously reported studies from other coal mine sites. 

Analyses of freshwater collected at a stream at the Qullissat mine site did not show elevated heavy metal levels. Yet, the sampling period was very dry and ochre precipitates on the soil surface in some places indicate that leaching of heavy metals may occur during some (wetter) periods of the year, i.e. during rain events or thawing of the snow cover. Yet, the limited spatial extent of the ochre precipitates also indicates that this is only likely to be of local importance.  

Lichen analyses showed that some heavy metals, such as chromium, were moderately elevated in lichens at a few locations within the Qullissat mine site compared to lichens collected at a reference site. This indicates that some dust dispersion with heavy metals may occur at the site. However, the moderate levels and an absence of concentration gradient reflecting the dominant wind pattern also indicate that dust dispersion with heavy metals is not likely to be a significant source of contamination at the site.  

Analyses of heavy metals in marine sediment collected in the tidal zone showed that the heavy metal composition in sediment collected near the Qullissat mine site and adjacent to a waste dump in the Qullissat mining town did not differ markedly from sediment collected at a reference site north of Qullissat mining town. However, concentrations of copper and nickel were generally high in the entire area compared to other areas in Greenland. This is consistent with previous studies, which showed that sediment near Disko in general contains elevated levels of copper, nickel and some other metals due to leaching from tertiary volcanic rocks. If Norwegian guidelines for environ-mental sediment quality is applied (no present Greenlandic guidelines exist), sediment sampled at Qullissat can be classified as ‘Bad’ based on the copper and nickel concentrations. Consequently, it is possible that the copper and nickel content in the sediment at Qullissat can have ecotoxicological effects on especially the sediment-living organisms in the area. However, if this is the case, it is considered a natural impact not related to the mining activities.  

Analyses of PAH compounds in marine sediment from the tidal zone showed that some of the sediments sampled close to the mine site were moderately elevated compared to sediment from the reference site. The PAH levels in these samples were relatively high compared to previously reported data from other parts of West Greenland but lower than for typical sediment in e.g. Denmark. The PAHs in the sediment at Qullissat are likely to originate both from coal residues from the mining activities and from natural seeps in the area. If the Norwegian guidelines for environmental sediment quality are applied, all sediment sampled at Qullissat can be classified as ‘Background’ or ‘Good’ based on the PAH content. This indicates that, despite the moderately elevated PAH levels in sediment at Qullissat, the PAH levels observed are not likely to be of significant environmental importance. It shall be noted that this assessment is only based on onshore sediment since no offshore sediment was sampled.  

In conclusion, based on the results from this study, it is DCE’s assessment that there is no indication of any significant contamination of the surrounding environment at Qullissat neither from the Qullissat mine site nor from the Qullissat town. Also, due to the relatively low levels of PAHs and other pollutants found in the study, DCE does not find that the area has obvious re-search potential with regards to studying effects of chronic exposure. It shall be noted, however, that this conclusion is based on relatively few samples and sample types taken during a short period of time. For potential future and more comprehensive studies in the area, it could be relevant also to include offshore sediment samples from deeper waters, marine biota and water samples taken at different times of the year.  

Finally, it shall be noted that this study is based solely on assessment of analysed chemical compositions in environmental samples. Local environmental impact such as mechanical damage to vegetation at the mine site and mining town due to remains of buildings, removal of surface soil, ochre precipitates etc. was not part of the study.