Emerging environmental pollutants include compounds that are not routinely monitored but which have the potential to cause adverse ecological impacts. Here we report on the presence and environmental fate of illicit compounds in the Hawkesbury-Nepean river system. The occurrence of illicit compounds including; amphetamine, cocaine, mdma, and associated metabolites were found in STP discharge locations at levels that were in some instances, above those reported in similar international studies. The persistence of these compounds is not limited to the immediate discharge area, with detectable levels measured at distances downstream. Data will be presented on laboratory studies exploring the fate of these illicit drugs under simulated environmental conditions. Management of STP discharge requires an increased understanding of the fate of these emerging environmental pollutants in the rapidly urbanising Sydney landscape.