Our paper presents results of a study concerning ammonium and nitrate(V) uptake by soil irrigated with communal wastewaters (1 and 2 doses) and estimation of the possibility of using organic soil and willow (Salix americana) for wastewater cleaning. It was found that the highest biological and physical purification effect by studied soil and plant was observed after the first 24 hours from the moment of the wastewaters application. It was also demonstrated that a single irrigation dose was better utilized than a double dose. An effect of the season of the year on the final purification effect was observed. It was concluded that the studied soil and the plant applied showed very high capacity of binding ammonium ions (up to 96%), and lower in the case of nitrates(V) (up to 69%).