There are considerable concerns that wastewater treatment processes will be unable to effectively remove elevated antiviral Oseltamivir carboxylate (OC) concentrations during a pandemic wave and that toxic exposures might result in urban receiving waters. A risk management framework for the wastewater system under such catastrophic stress conditions is outlined with the main focus being on the protection of critical functions, services and workforce operations. A generic risk assessment approach for predicting OC removal rates in sewage treatment works (STWr) and receiving surface water concentrations (PECSW) is examined. The wide range of predicted daily concentrations values varying between 20 and– 10310µg L-1 d-1 resulting from the application of the modelling approach and this confers little confidence in the risk methodology and argues that toxicological risk for OC pandemics remains insufficiently characterised. The operation of STW unit treatment process however, would appear to be relatively robust under predicted pandemic stress conditions in terms of functional performance although system management difficulties might predicate optimal removal rates
