This work gives an in-depth overview of the photodegradation capacities of selected xenobiotics present in effluents of conventional wastewater treatment plants. We performed a qualitative and quantitative overview of literature data describing the photodegradation of pesticides and pharmaceuticals. In this aim, we built a database by compiling the results of experimental photodegradation assays found in the literature. Special attention was devoted to selecting the data and compiling reliable results relevant to photodegradation half-life. We also included metadata such as the experimental operating conditions and by-products information. Finally, we used the output of the database in association with a simple model to predict photodegradation for selected xenobiotics in a tertiary polishing pond. We have demonstrated the potentiality of this model and we propose modification and specific experimental measurements to carry out to improve prediction.