One of the wastes that are generated in sewage treatment plants are sediments. The methods of their final management depend on the sewage sludge system management. One of the methods used is Autothermal Thermophilic Aerobic Digestion (ATAD). The article presents the process of autothermal oxygen digestion of sewage sludge as a method enabling the obtaining of biomass, which can be used in the natural environment. In addition to the description of the theoretical basis of the discussed process, the quality of sewage sludge formed is presented. The amount of sludge formed and the manner of their its final utilisation were also analyzed. The results are presented on the basis of waste records kept in each of the analyzed sewage treatment plants. Sludge transfer cards in 2013-2018 were also analyzed in sewage treatment plants where sludge undergoes the ATAD process.