Wastewater surveillance has emerged as one of public health's most innovative tools, offering early warning signs of disease outbreaks and filling critical gaps left by traditional surveillance systems. Breanna McArdle, epidemiologist and program manager for Washington state's wastewater-based epidemiology program, explains how public health agencies decide which pathogens to monitor, why wastewater data must be interpreted alongside other surveillance sources, and how the field is evolving beyond its origins in the COVID-19 pandemic. McArdle also explores the ethical and privacy considerations of wastewater surveillance, the challenges of communicating findings to communities and policymakers, and the importance of partnerships with local health departments, treatment plant operators, laboratories, and academic researchers. She discusses how investments in data infrastructure, laboratory science, and cross-sector collaboration are helping transform wastewater surveillance into a versatile tool for tracking a wide range of public health threats.