The mapping includes catchment delineation, ice- and land runoff modelling, ice-dynamic modelling of the age of the melting ice, collection of fjord depth data and an assessment of the risk from glacial lake outburst floods. An extensive analysis of chemical, physical and microbiological parameters were performed on the water samples collected during field-work. Some types of analysis had to be performed on-site, some were performed at GEUS laboratories, and some at certified commercial laboratories.
Greenland has a diverse geology including areas with potential for mining of metals and radioactive isotopes. The existence of such areas could influence the water quality in melt-water rivers. The 2017 survey, however, showed excellent water quality at all locations with regards to inorganics like metal ions and radioisotopes. Toxic metals like arsenic, cadmium and nickel were well below the lowest criterion at all locations and so was fluoride, which may be an indicator for a number of toxic metals in Southern Greenland. Radioactivity was below the detection limit of the commercial laboratory at all locations. The seasonal varia-tion of metals and radioisotopes is not yet known, but so far the locations look promising with regards to these quality parameters.
Biology is another factor that may influence water quality of meltwater rivers. Of most con-cern are cyanobacteria in lakes and rivers and bacteria from the gut of animals. Cyanobac-teria produce toxins like microcystins and Anatoxin-A. These compounds were not detected at any of the locations. Coliforms and enterococci were chosen as indicator bacteria. Coli-forms were not found at any location. Enterococcaceae were detected only at one location (2 per 5 mL). Total colony forming units (CFU) at 22 and 36°C were also analysed. While some CFU were found at 22°C (7-115 per mL) almost none were found at 36°C (0-2 per mL), which is a good safety indication. The bacterial parameters generally indicated good water quality, but some sort of simple disinfection should be considered, as is the case for all surface water for human consumption.
In summary, the results indicate an excellent water quality at all five locations, with all pa-rameter values below the required drinking water standards for the European Union, the United States and The International Council of Bottled Water Associations (ICBWA) .
|Status||Udgivet - 25 sep. 2019|
|Navn||Danmarks og Grønlands Geologiske Undersøgelse Rapport|
- Programområde 5: Natur og klima