Article presents study of controlling the contents of wastewater by means of automation of the wastewater supply with machine for biological treatment of urban wastewater of Kamianske city - aerated pond. We have investigated the automation of the aeration and wastewater treatment system in an aerated pond by means of equipping the system with a water and silt mixture depth sensing element and an electric motor, which will provide the ability to automatically control the supply of air to the aerator, coordinated with the drainage system to maintain an optimal cleaning mode. Such techniques contribute to an increased reliability of the treatment facilities operation under the conditions of quick fluctuations in the volume of sewage water entering the aerated ponds. The problem was that due to the fluctuations, workers had to manually adjust the sludge flow and the intensity of air supply to the aeration tank every hour. It is presented a daily dynamics of the wastewater flow into the treatment facilities of the left bank of Kamianske city and the hourly change in dissolved oxygen concentration. Also the average of nitrogen and phosphates concentration in the source wastewater from December 2020 to May 2022 is shown. It is found that contents of saline ammonium is decreased from 7.50 mg/dm3 in untreated wastewater to 2.00 mg/dm3 in treated one. The process of wastewater treatment in the aerated pond using a three-dimensional mathematical model was simulated. Thanks to the research the efficiency of wastewater treatment increases, and there is an urgent issue of further research to reduce the concentration of phosphates in such machines to the norms of discharge into the river Dnipro.