The industrial area of Ravne Ironworks is located in eastern part of Mežica valley. Today there are several companies operating in this industrial area, which together form corporation SIJ d.o.o. Some of the activities taking place in this area pose a potential risk for pollution of the environment and also groundwater. In order to determine the distribution of groundwater I worked in my dissertation on hydrogeological conditions in the economic area of Železarna Ravne. The aquifer consists of quartz deposits of the Meža River, which consists mainly of gravel and melt. Its thickness is between 5,50 m and 12,80 m and is well-permeable. With pumping tests and percolation test I calculated the coefficient of permeability of aquifer, which on average amounts 9,96x10-3 m/s. I also measured the electrical conductivity of groundwater and I discovered that it rises downstream from west of this area to east. On the basis of the measurements of the electroconductivity of the Meža River, I believe that the river in this area has no significant influence on the groundwater.