Ala Lombolo
- One of Sweden's most polluted lakes
The future
Since the findings of the high contents of mercury in Ala Lombolo in the beginning of the 1990s, the lake has been a feverish subject of conversation both in the region and at a national level. Even though the lake’s poor condition has been known for almost 30 years and a lot of investigations have been carried out, it has still not been remediated.
The fact that the lake has been polluted by various contaminants, by several different parties, over a very long period of time when environmental legislation was virtually non-existent, makes it difficult to identify a single responsible party for this expensive remediation, something that has slowed down the remediation project. After some debate, the remediation project was finally started in the fall of 2014. It is led by the Geological Survey of Sweden (SGU) in cooperation with the mining company LKAB, the municipality of Kiruna and the County Administration Board of Norrbotten, with governmental financial support from the Swedish Environmental Protection Agency. (SGU, 2014, 11 September)
The method which will be used to remediate Ala Lombolo is described in the local newspaper by Dahlström (2016, 6 April). She explaines that the lake sediments will be dredged and then pumped into tubes on land where excess water will be released. The tubes will then be left to freeze for a season. When thawing, the sediments will release more water and this will minimise the amount of material which needs to be further treated. The final step is to treat the sediments thermally to get rid of the mercury under controlled conditions (Linder, 2015, 2 September).
If the propagating fractures would not have been a present threat, an optional remediation method could be to lock up the contaminated sediments with an artificial lake bottom. It remains unclear how widespread the fractures will get in the future and up until 2005 LKAB had not yet made any forecasts of the fracture propagation in the direction of Ala Lombolo. (Sveriges Radio Norrbotten, 2005, 14 October)
The Armed Forces has been responsible for collecting the dumped ammunition, a necessary prerequisite to be able to initiate dredging. In September 2014 the last of the 173 boxes of grenades was found and destroyed (Jirlind, 2014, 11 September).
In the summer of 2016, the dredging was supposed to be tested in a smaller pilot project (Dahlström, 2016, 6 April). However, new findings of the explosive nitroglycerine which has leached from the dumped ammunition, forced the dredging plans to be postponed until the summer of 2017 (Linder, 2016, 8 August). If the nitroglycerin cannot be remediated properly it might, due to the risk of explosion, be necessary to do a freeze dredging instead, i.e. freeze the bottom sediments in situ and lift it out of the lake part by part (Sveriges Radio Norrbotten, 2005, 14 October).
LKAB’s draining of the lake Luossajärvi in order to prevent water to flow into the mine through the fractures has been questioned not only by the municipality of Kiruna and its citizens, but also by several neighboring municipalities. The concern is that the subsequent flow changes in Ala Lombolo will spread mercury and other pollutants into Torne Älv. The draining has been approved by the Environmental Court of Justice under the premise that LKAB continuously pump water to Ala Lombolo to maintain a stable water level (Sveriges Radio Norrbotten, 2011, 14 January)
The Armed Forces has been responsible for collecting the dumped ammunition and in September 2014 the last box of grenades was found and destroyed. Findings of nitroglycerine which has leached from the dumped ammunition have caused the dredging plans to be postponed. Photos: Försvarsmakten