One of the most serious problems occurring during coal extraction in Upper Silesia in Poland is caused by waters with very high salinity. These waters often contain also high concentrations of natural radionuclides, mainly 226Ra from uranium series and 228Ra from thorium series. At least 70% of the total amount of radium carried by this waters remains nowadays in underground galleries as radioactive deposits. But, during the period of the most extensive coal extraction up to 225 MBq of 226Ra and 400 MBq of 228Ra were released daily into surface along with the other mine effluents. As a result of discharge of radium-bearing waters into settling ponds and later into rivers a significant increase of radium concentration in bottom sediments has been observed. Sometimes there is also a contamination of river beds, soils and biota. The paper describes results of investigation of waters and sediments with enhanced natural radioactivity, that occur in settling ponds, where mine waters have been dumped. Measurements of different factors of radiological hazard were made, such as radium content in the soil from ponds' banks, variations of gamma radiation background and radon exhalation. Additionally radium transfer to vegetation that had transgressed into the ponds has been calculated.