Groundwater Transport of Sulphates in the Estonian Oil Shale Mining Area

Abstract

The development of Estonian power engineering on
the basis of oil shale has caused several changes in the
environment. One phenomena which accompanies oil shale
mining is heightened content of sulphates in groundwater and
surface water.
The aim of this research is to give an overview of groundwater
and surface water transport of sulphates in the Estonian oil shale mining area and find out the regularity of its distribution during the time. As is known the aquifer containing the exploitable oil shale seam is influenced by mining activities the most, but also the quality of upper and lower aquifers can change. It is very important to clear up the vertical distribution of sulphates in
different water-bearing horizons.
The phosphorite mining area which finished its activity in 1991
is also included in the research. The aim is to clear up to what
extent environmental conditions have become better and draw conclusions on the ground of old closed mines for working mines for getting to know how much time it will take for self-cleaning of the environment.