Urban drainage pollutant emissions from waste water treatment plants, stormwater and combined sewer overflows into receiving waters

The aim is to conduct a comparison of the freight-related pathways of the urban surface runoff via wastewater treatment plants, combined sewer overflows and stormwater discharge from stormwater sewers. Based on the freight assessment, a proposal for measures to reduce the potential emissions to receiving waters are elaborated. The main objective is to assess the extent to which measures should be targeted at other entry points as wastewater treatment plants. In addition, due to the sampling of rainwater, a limited evaluation of this diffuse path is possible. Some substances or groups of substances (such as mercury or polybrominated diphenyl ethers) are transported through the air and the deposition represents a significant path into the aquatic systems. For such substances, relevant reduction of emissions through costly technical measures at the WWTPs are rather of very limited success. The mass balances for the relevant substances will be considered and examined for different scenarios in the course of the project.