Eight samples each of coal ash taken from active, currently filled, and passive, previously filled cassettes of "Nikola Tesla A" power plant dump (Obrenovac near Belgrade, Serbia) were subjected to a sequential extraction, comprising of the following five phases: distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, acidic solution of H2O2, and 6 M solution of HCl. Leached concentrations were discussed from the standpoint of their environmental significance, keeping in mind the processes occurring during and after coal ash transport to the dump, as well as the concentrations washed from the original filter lignite ash.