A public discussion took place in Rakvere on 12 December 2019 on the study of Sillamäe groundwater, carried out by the EGT Department of Hydrogeology and Environmental Geology.
An analysis of fresh and older chemical data indicated that the increase of Cl concentration in wells of Sillamäe is likely caused by intrusion of salty water from the lower (clayey) part of the Voronka aquifer or from the Kotlin aquitard. However, there are several contradictions in the results, and the risk of intrusion of sea water should be considered, particularly in the NW part of Sillamäe.
The study showed also that technical condition of a local drilled well reaching the Gdov aquifer may pose a threat on the overlying freshwater layer, which is principally the only freshwater resource in Sillamäe.
