The introductory chapter provides an overview of the importance of wastewater-based epidemiology in monitoring infectious diseases. It emphasizes the potential for detecting and quantifying viral RNA in wastewater as a tool for early detection, surveillance, and public health interventions. The materials and methods section describes the sampling and analysis techniques used in this master's thesis, specifically the process of collecting wastewater samples from various locations in the city of Rijeka and the qPCR analysis process for detecting and quantifying SARS-CoV-2 RNA. The rationale behind the selection of sampling locations is also highlighted, including considerations such as proximity to specific public health institutions, as well as the frequency and duration of sampling. The data processing and presentation of results include data collected through qPCR analysis of wastewater samples. It includes graphical representations of fluorescence intensities and standard curves used in quantification. It also highlights the differences in viral concentrations between sampling locations and the importance of considering external factors such as meteorological conditions during sampling. The discussion delves deeper into the results and insights of the research itself. It emphasizes the successful establishment of methods for detecting and quantifying SARS-CoV-2 RNA in wastewater. However, it also mentions numerous challenges and limitations of wastewater-based epidemiology, such as the lack of a standard definition for positive samples and the need for further research and methodological development. Finally, the conclusion summarizes the main findings and implications of the thesis. It emphasizes the value of wastewater monitoring for early detection, surveillance, and public health interventions, as well as the potential of wastewater-based epidemiology in monitoring not only SARS-CoV-2 but also other emerging viral diseases. Overall, the thesis demonstrates the utility of wastewater-based epidemiology in detecting and monitoring infectious diseases, providing valuable insights for public health institutions.