Since the beginning of 19th century, the site of the “Tarnowskie Góry” Chemical Works has seen all kinds intensive industrial activity. The activity was combined with generating waste which traditionally used to be dumped in unprotected landfills. Some 1,5 million cubic meters of waste has been accumulated - most of it hazardous. The main pollutants, which find their way into the water table through the natural leaching process, include barium, boron, strontium, zink and copper. “Tarnowskie Góry” closed down in 1995. This was accompanied by efforts to eliminate the environmental hazards through the neutralisation of the waste material dumped in unprotected landfills. The research showed that the best way of achieving this would be a leak-proof landfill compliant with the Polish and UE environmental legislation.