Wastewater-based epidemiology (or wastewater-based surveillance or sewage chemical-information mining) analyzes wastewater to determine the consumption of, or exposure to, chemicals or pathogens in a population. This is achieved by measuring chemical or biomarkers in wastewater generated by the people contributing to a sewage treatment plant catchment.[1] Wastewater-based epidemiology has been used to estimate illicit drug use in communities or populations, but can be used to measure the consumption of alcohol, caffeine, various pharmaceuticals and other compounds.[2] Wastewater-based epidemiology has also been adapted to measure the load of pathogens such as SARS-CoV-2 in a community.[3] It differs from traditional drug testing, urine or stool testing in that results are population-level rather than individual level. Wastewater-based epidemiology is an interdisciplinary endeavour that draws on input from specialists such as wastewater treatment plant operators, analytical chemists and epidemiologists.