Electricity and heat have been produced in Poland by the combustion of coal. Ash-slag, a by-product of this process, has been mainly deposited in landfills. Until the end of 2011, about 258 million tonnes of ash-slag have been deposited in landfills. Herbaceous plant and soil samples were taken from four directions (east, west, south and north) in three locations on the landfill embankment: base, middle and top. The negative influence of furnace waste landfill on herbaceous plants was confirmed by the phytoaccumulation indexes (WF) of the examined elements: WF Cd - medium to intensive; WF Pb - low to medium; WF Zn - low to intensive and WF Cu - low to medium.