17 Natura 2000 nature sites, 6 bird sites, and a large part of the water-dependent habitat types are located on top of the Estonian oil shale deposit

In 1996, an Australian study found that underground mining has an impact on water and biodiversity [1]. This impact is smaller than that of surface mining; the changes it causes will be felt over time and will be more concentrated in the area of the mine’s surface facilities (buildings, roads, mining stocks).

In the case of underground mines, the focus is on mitigation of impacts with a larger scale. One such impact that needs to be addressed is the reduction of groundwater levels in the area, as it threatens species that need moist habitats for their livelihoods. Due to the resulting drainage, the growth of woody plants accelerates where it is important that the stand is thinner. Another important effect is the engulfment of the ground, which results in the formation of a water body that destroys the original community of the area. However, the impact of underground mining is difficult to distinguish from that of surface activities, and as the impact is a combination of several factors, habitat changes need to be analysed beyond the boundaries of the mining area [2].

In Estonia, there are several nature conservation areas in the areas of oil shale underground mines with active and inactive reserves. 17 Natura 2000 nature sites, 6 bird sites, and a large part of the water-dependent habitat types are located on top of the entire Estonian oil shale deposit [3]. The impact of the Estonia mine on the Selisoo and Muraka nature reserves showed that with the existing mining technology, the preservation of the water regime in these areas is not guaranteed [4]. The construction of new mines is possible if mitigation measures are implemented. Sufficient buffer zones can be left between the protected areas and the mines and thorough research can be used in the planning; the construction of underground mines under protected areas can also be avoided [4]. However, the interests of the parties often conflict and economic interests may outweigh natural values.

                                                                                                                                               Text: Kristjan Piirimäe, Kuno Kasak

                                                                                                                                                Editors: Sigrid Ots, Reigo Roasto

Last modified: 13.01.2022

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[1] P. Davies, N. Mitchell, L. Barmuta. The impact of historical mining operations at Mount Lyell on the water quality and biological health of the King and Queen River catchments, western Tasmania. In Mount Lyell Remediation Research and Demonstration Program, Supervising Scientist Report 118. Office of the Supervising Scientist, Canberra, 1996. https://www.environment.gov.au/system/files/resources/adbd8065-a57a-4f29-a151-ae5edea65496/files/ssr118.pdf

[2] Keskkonnaministeerium. 2015. Põlevkivi kasutamise riiklik arengukava 2016-2030. https://www.riigiteataja.ee/aktilisa/3180/3201/6002/RKo_16032016_Lisa.pdf

[3] M. Metsur, I. Tamm. Põlevkivi kasutamise riikliku arengukava 2016-2030 keskkonnamõju strateegiline hindamise aruanne. 

[4] T. Hang, H. Hiiemaa, M. Järveoja, A. Jõeleht, V. Kalm, E. Karro, M. Kohv, M. Mustasaar, M. Polikarpus, J. Plado. Ratva raba hüdrogeoloogiline uuring ja Selisoo seiresüsteemi rajamine. KIK projekti nr 15 aruanne. Tartu Ülikooli geoloogia osakond, 2012 https://www.geoloogia.ut.ee/sites/default/files/geoloogia/ratvaseliaruannetdcgeoloogia.pdf