Ensuring the safety of drinking water and environmental water sources is a critical public health priority, with microbial contamination, particularly by fecal indicator bacteria like Escherichia coli (E. coli), posing significant risks. Traditional methods for detecting E. coli are often time-consuming, labor-intensive, and require specialized laboratory facilities, hindering rapid response to contamination events. This article explores the potential of capacitance biosensors as a rapid, label-free, and sensitive alternative for E. coli detection in water. The introduction highlights the importance of water quality monitoring and the limitations of current detection techniques. The methods section details the fundamental principles of impedance/capacitance microbiology and the design considerations for capacitance biosensors tailored for bacterial detection. The results synthesize current research demonstrating the efficacy of these biosensors in real-time monitoring of bacterial activity and specific pathogen identification. The discussion interprets the advantages and challenges of capacitance biosensors, emphasizing their potential for decentralized, on-site water quality assessment, and outlines future directions for research and development to achieve widespread adoption.