The paper presents analysis of modernization possibilities of the techno-logical chain in the sewage treatment plant in Lopuszna concerning removal of biogenic pollutants. High operation effectiveness of the analyzed treatment plant is important regarding the protection of water in the cascade of Czorsztyn-Niedzica-Sromowce Wyzne reservoirs against the excessive pollution. The assess-ment of modernization possibilities of the treatment plant was based on the num-ber of computer simulations upon the ASIM2d model. This model includes 21 separate processes, which were divided into: hydrolysis processes, processes with heterotrophic bacteria XH, processes with poliphosphates' accumulating bacteria XPAO, processes with nitrifiers XAUT and chemical processes.The analysis revealed that low effectiveness of biogenic substance removal in the objective treatment plant results from the lack of activated sludge recircula-tion into the anaerobic chamber which causes that the biological dephosphatation process is not sufficient enough. The situation will change if the internal and external recirculation chain is corrected and the anaerobic chamber is included in the technological chain of the objective sewage treatment plant. ...
