Resumen
The content of the paper is focused on determining the influence of an old municipal landfill site on the pollution of soil and groundwater by ammonium. The assessment of the influence was conducted on piezometric recording basis, laboratory tests and site investigation, which gave information on contamination level and direction of pollutants migration. Based on the groundwater monitoring results, several maps of groundwater level changes were created. Moreover, mapping of ammonium distribution and migration paths within Lubna Landfill surroundings was also provided. The monitoring data show improvement of water quality in almost every piezometer after only a few years from when groundwater protection system was installed at the site. It indicates that reduction of ammonium within the vicinity of the landfill is continuously progressing in time. On the basis of the results obtained, the magnitude of variability in pollutant migration and changes in concentration, as well as efficiency of the vertical barrier were assessed.