The paper presents the results of research on using radio frequency identification (RFID) technologies to prevent pollution by enabling early detection of industrial discharges. The goal of the study is to develop a method for detecting unauthorized connections to storm sewers using passive RFID technology. The authors justify the choice of passive RFID, based on the EPC Class 1 Gen2 standard (ISO/IEC 18000-63:2021(E)). The authors describe experiments to reliably detect RFID tags floating in protective casings on the water’s surface by reader with the antenna positioned 0.5–1.5 m above the water. A key challenge is the difficulty in reading tags directly on the water’s surface, as water shields and reflects the reader’s electromagnetic waves. Additional tests were conducted to evaluate the impact of tag collisions on the accuracy and completeness of readings, as these collisions may cause missed tags when passing by the reader’s antenna. The study confirms that passive RFID can address key challenges in detecting unauthorized storm sewer connections. RFID technology has the potential to improve the efficiency and accuracy of environmental monitoring, reduce control costs, and better protect water bodies from industrial pollution. The research is significant for advancing new methods and technologies in environmental protection and can be applied in state environmental control systems to identify and prevent unauthorized wastewater discharges from industrial facilities.