Greenlandic Ice Cap Water – hydrological studies and data collection Greenlandic Ice Cap Water

Drinking water of high quality is becoming a scarce resource worldwide. As the world population grows, demand is rising while the supply is under pressure from the impact of climate change.

In Greenland, pure meltwater running off the Greenlandic Ice Sheet provides the solution. As the annual hydrological cycle intensifies with higher temperatures in the Arctic, the available water resource only increases. Unlike mountain glaciers which are vanishing globally, the Greenlandic Ice Sheet is vast, containing 2,85 million cubic kilometres of pure glacier ice providing a freshwater reservoir without equal in the northern hemisphere.

The Greenlandic Ice Sheet covers most of the land in Greenland with rivers tranporting the meltwater Panoramic view of L-04 near Maniitsoq, with the a short distance through the mountains to the outlet of the lake on the left side and the fjord on fjords through the largely uninhabited country. In the right side. southwestern Greenland, the fjords provide access to the mouths of the meltwater rivers with opportunities for direct access by ship. kilometres of inland ice, eventually compacting under The Government of Greenland actively supports the the weight of new layers of snow to become glacier prospect of drinking water export from this immense ice. With enough weight on top, ice crystals deform, resource. To attract investments from the industry, an recrystallize and slide causing the glacier ice to move. extensive effort has been launched to map possible Over millenia, the ancient snow is transported through extraction locations, ensure the quality of the The ice sheet from the great white plains of the interior meltwater and review the existing ice & water export to the ice margin. Here it breaks off as icebergs into legislation. the fjords or melts, causing new fresh layers of ice to resurface constantly. The age of the ice that melts Mapping and water quality assessments are spans the whole period of the human civilization and undertaken by the Geological Survey of Denmark and before. Greenland (GEUS) adhering to the highest international standards. GEUS has been charged by the Government The Greenlandic Ice Sheet provides an abundant source of Greenland to identify suitable locations for of meltwater on a seasonal basis. Thus, an important extraction of drinking water from meltwater rivers, factor is the length of the melting season which is most conduct field investigations & water sampling and extensive in southwestern Greenland lasting from subsequently carry out water quality assessments late May to mid September. This part of Greenland is in certified laboratories. GEUS is the National accessible by ship throughout the year with occasional Data Centre for water quality information for all icebergs dotting the horizon. A variety of fjord water of Denmarks more than 280,000 drinking water wells depth measurements are available and the waters and has carried out extensive geoscientific fieldwork in covered by regular nautical charts is under contract with Greenland since 1946. the Danish Government to expand significantly over the next few years. Generally speaking, Greenlandic fjords are very deep, but the ice sheet is slowly eroding the The largest and most pristine underlying rock and produces sediment that may cause freshwater reservoir in the Northern shallower waters in some locations. Hemisphere The Greenlandic Ice Sheet has covered Greenland for The meltwater sediment settles slowly, but the the last 2,5 million years, growing during the ice ages majority of the locations investigated are supplied and shrinking in the warm periods like the present. by meltwater rivers interrupted by one or more lakes Each year, fresh snow settles on the 1,7 million square on their way from the ice sheet margin to the ocean.

2 Greenlandic Ice Cap Water

This allows for a large fraction of the sediment to Locations of interest settle, reducing the filtering needs. The Government of Greenland has initiated a comprehensive mapping of prospective locations, The ice sheet margin is retreating in many places, effectuated by GEUS. The initial assessment potentially creating a changing runoff pattern as of locations is based on a three-level approach: the surface lowers. However, as the majority of the Accessibility, Abundance & Water quality, where each meltwater is produced close to the ice sheet margin, level is dependent on the former. the discharge from the larger catchments under investigation are rather insensitive to ice elevation At each level, five different criteria is identified and changes. assigned a weight in the assessment with the goal to single out the most promising locations to visit in the As Greenland is mostly uninhabited, river discharge is field. generally only known from hydrological models. Only a few catchments of interest for hydropower have been The accessibility criteria includes proximity to gauged, but these show a strong increase in the amount infrastructure, marine chart coverage, availability of meltwater of up to 80 % over the recent decade. of bathymetry data and abundance of sea ice and icebergs, respectively.

Catchment delineation example for a location L-02 south of Nuuk, SW Greenland.

3 Greenlandic Ice Cap Water Ilulissat

The abundance criteria relates to water discharge, length of the melt season, existence of proglacial Sisimiut lakes, risk of outburst floods and upstream catchment Kangerlussuaq changes.

Finally the water quality criteria focuses on origin of L-04 the water, age of the source ice, expected sediment L-05 concentration in the meltwater and other issues from Maniitsoq contact with naturally occurring minerals. Each location is meticulously examined and rated with respect to the 15 criteria from the considerable Nuuk geospatial, geological and geochemical datasets L-03 available to the Government of Greenland and GEUS. L-02 Locations are defined as outlets of a significant meltwater rivers to accessible fjords in the L-01 southwestern part of Greenland, to minimize potential Paamiut sea ice and iceberg interference.

Catchments for each location or river outlet is derived Narsarsuaq employing advanced hydrological methods, using the most recent elevation models available. Qaqortoq

The increase in 250 km the ice sheet melt between 1980-91 Overview of five locations identified as and 2003-2014 prospective sources of drinking water. given in mm water equivalent.

60 2003

1980

40

Monthly 20 intensification of the ice sheet Monthly discharge [Gt] mm w.eq. melt in Southwest Greenland 0 between 1980-91 Apr May Jun Jul Aug Sep Oct Nov 800 600 400 200 0 and 2003-2014. Month

4 Greenlandic Ice Cap Water

Location L-03, overlooking the fjord near Nuuk.

Subsequently, results from a regional climate model is used to calculate the average monthly discharge expected at each location from precipitation and The geology of Greenland is rich and diverse, adding to meltwater leaving the catchment. This method was the unique nature of the meltwater from the ice sheet, also used to examine the change in discharge over the but also requiring attention to the inorganic content last few decades, showing a promising overall melt such as metal ions and radioisotopes. The analysis thus increase of more than 50 % for the region. included a screening for radioactivity and potentially toxic metals such as arsenic, cadmium and nickel, as Five locations were visited by boat to sample the water well as fluoride, which serves as an indicator for toxic and collect additional data. Two locations draining metals in the region. The results indicate mineral water ice sheet catchments and three locations draining of high quality in all 5 areas. catchments with local mountain glaciers. An extensive analysis of chemical, physical and microbiological The meltwater runs off the glaciers, through vast parameters was performed on the water samples. glacial forelands and dramatic gorges, rich in wild Some types of analyses had to be performed on-site, Arctic flora and fauna. While this voyage shapes some were performed at GEUS laboratories and some the distinctive character of the water at each at certified commercial laboratories. location, it also implies that biology is a factor

Table. Analytical program for chemical and microbiological parameters Parameter Type of analysis Place of analysis Container Comment pH Electrode On-site+GEUS - Oxygen Electrode On-site - Conductivity Electrode On-site - Anions1 Ion chromatograph GEUS Filtration + cooling 50 mL plastic Cations2 Ion chromatograph GEUS Filtration + cooling Trace metals DS/EN ISO 17294m:2016 ICP-MS Eurofins 30 mL plastic Acid conservation Radioactivity ISO 10704+13168:2015 Eurofins 250 mL plastic Microcystins ISO 20179 mod. LC-MS/MS Eurofins 100 mL glass Added thiosulfate Anatoxin-A-fumarat LC-MS Eurofins 1 L glass 36°C incubator Coliform bacteria 3M Petrifilm Aqua x5 On-boat Undiluted 21h 36°C incubator Enterobacteriaceae 3M Petrifilm Aqua x5 On-boat Undiluted 21h 22°C incubator Total CFU 3M Petrifilm Aqua 2x5 On-boat Undiluted + 10x 68h 36°C incubator Thermotolerant CFU* 3M Petrifilm Aqua x5 On-boat Undiluted 44h *Method developed for total CFU but adapted to thermotolerant CFU. 1 Fluoride, chloride, bromide, sulfate, nitrate, phosphate. 2 Sodium, potassium, calcium, magnesium.

5 Greenlandic Ice Cap Water

requiring consideration. The analysis thus included of the potential for export of drinking water from cyanobacterial toxins (microcystins and anatoxin-a) meltwater rivers in Greenland. as well as counts of enterobacteria and total heterotrophic bacteria. No cyanotoxins were detected A detailed technical report is available with a full at any of the locations, but as expected for natural description of the analysis design and sampling surface water, microbial counts suggest that gentle strategy, including a water quality evaluation of the treatment with UV light is advisable. results.* Further field investigations, including visits to additional potential locations, are underway to obtain While the water quality can be expected to vary over information on the seasonal variability of water quality the season, the results provide a strong indication parameters.

Table. Content of inorganic ions and trace metals at the five locations visited

Parameter Unit L-01 L-02 L-03 L-04 L-05 Criterion

pHfield - 6,6 6,4 6,2 6,8 6,1 6,5-8,0

pHlab - 6,38 6,74 6,25 6,69 6,17 6,5-8,0

Alkalinitylab meqv/l 0,13 0,08 0,05 0,13 0,04 -

Conductivityfield mS/m 15 15 13 22 15 <250

Tempfield °C 3,7 4,1 4,1 2,9 1,3 - F- mg/L <0,04 <0,04 <0,04 <0,04 <0,04 1,5 Cl- mg/L 0,68 0,51 1,12 0,99 2,41 250 - NO3 mg/L 0,38 0,10 0,07 0,09 0,13 44 3- PO4 mg/L <0,05 <0,05 <0,05 <0,05 <0,05 - 2- SO4 mg/L 0,91 2,35 1,27 3,03 0,99 250 Na+ mg/L 0,74 0,66 0,88 0,99 1,64 175 K+ mg/L 0,82 0,65 0,42 0,38 0,15 - Ca2+ mg/L 1,44 1,50 0,88 2,11 0,53 - Mg2+ mg/L 0,25 0,21 0,20 0,65 0,26 50 Antimony (Sb) µg/L < 0,2 < 0,2 < 0,2 < 0,2 < 0,2 5 Arsenic (As) µg/L 0,081 0,097 < 0,03 < 0,03 < 0,03 5 Barium (Ba) µg/L 67 34 5,8 3,1 < 1 700 Lead (Pb) µg/L 0,65 0,63 0,075 0,044 0,12 10 Boron (B) µg/L < 1 1,9 1,8 1,4 3,3 300 Cadmium (Cd) µg/L 0,0035 < 0,003 < 0,003 < 0,003 < 0,003 3 Chromium(Cr) µg/L 12 4,7 0,094 0,094 < 0,03 50 Cobalt (Co) µg/L 3,1 1,5 0,07 < 0,04 < 0,04 5 Cobber (Cu) µg/L 11 5,5 0,51 0,33 < 0,03 1000 Nickel (Ni) µg/L 12 5,3 0,33 0,68 0,32 20 Selenium (Se) µg/L < 0,05 < 0,05 < 0,05 0,068 < 0,05 10 Zink (Zn) µg/L 13 7,8 < 0,3 0,36 2,5 100

* Results of the analysis and all other information in relation thereto are provided “as is” and are only a general indication of the quality of the water at the place and time of the sampling of the water. The actual quality of the water may be different and may vary in different places and over time. The Government of Greenland and GEUS shall not have any obligation or liability for the analysis or their results or other information provided related to water, including among others the quality of the water and the estimated annual mean runoff. Companies applying for a licence to exploit water must therefore perform their own analysis of the water and matters in relation to the water. Companies granted an exploitation licence should therefore perform their own analysis of the water and matters in relation to the water before exploiting it.

6 Greenlandic Ice Cap Water

Ilulissat

Sisimiut Kangerlussuaq

L-04 Water quality sampling at the L-05 Maniitsoq five locations visited.

Nuuk L-03 L-02

L-01 Paamiut

Narsarsuaq Qaqortoq

L-03 250 km

L-04 L-02

L-05 L-01

7 Geological Survey of The Ministry of Industry and Energy Denmark and Greenland

Tel +299 34 50 00 www.businessingreenland.gl www.naalakkersuisut.gl P.O. Box 1601 3900 Nuuk Greenland

Authors: Andreas P. Ahlstrøm, Christian Albers, GEUS • Photographs: GEUS • Layout: Carsten E. Thuesen, GEUS • August 2018