An Environmental Impact Assessment of the underground operations at the designed Petrikov potash mine, Belarus

The Petrikov deposits of potash salt is situated in Gomel oblast of Belarus in the south-east of Pripyat Trough, and have Northern and Southern prospects. Underground mining of potash salt will start at the Northern prospect with an area of 166 km2. It is expected that mining will last for between 50-80 years. An Environmental Impact Assessment (EIA) was carried out at the design stage of the Petrikov mining and processing plant. The standard EIA procedure included a set of investigations, including assessments of surface subsidence, changes in groundwater level, changes in productivity of forest phytocoenoses and crops, and assessment of groundwater pollution due to production of potash fertilizers. Maximum values of possible surface subsidence (up to 2.3 m) will occur within the area, where the surface will be affected by the mining of potash layers 1, 2, and 3 of the productive horizon IV-Π, using a long-pillar mining system. Surface subsidence will influence surface topography, surface and groundwater, landscape structure and land resources. The result of surface subsidence will lead to inundation and swamping of land, as well as to an increase in the areas affected by annual floods in the valleys of the Pripyat and Bobrik rivers. Surface subsidence will affect the whole area of the prospect within the limits of planned mining fields, except the areas above safety pillars. In the result of raised groundwater levels the area with groundwater depth of more than 2 m will decrease from 69.1% to 17.8%, and the areas with groundwater depth from 3 to 5 m will disappear. The area with a groundwater depth less than 1 m will increase from 0.1% to 34.0%. In 19.5% of the area the groundwater level will raise above the surface level (the area of inundation). Surface subsidence and change in groundwater level will cause certain decreases in yields of timber and crops, and 2564 ha of forest, 68 ha of arable land and 324 ha of meadows will be inundated. In order to prevent inundation within certain areas protective engineering facilities have been designed, and an arrangement of groundwater monitoring wells has been proposed.