Towards an Integrated Monitoring and Modelling Approach for Particle-Bound Contaminants in Urbanised Catchments

Abstract

Urban runoff is a pathway of particles and particle-bound contaminants (PBCs) towards urban water bodies. These contaminants are emitted from urban wet weather discharges (i.e., combined and separate sewer networks) during storm events, creating health risks for humans, ecosystems and degrading water quality downstream. Due to the spatial and temporal variability of PBCs associated with different urban sources, accurately quantifying, characterising and identifying their transport pathways remains a major challenge. Modelling is a useful tool to study the dynamic behaviour of urban drainage systems. Hence, to understand the PBCs pathways at the interface between sewer systems and streams, we have established an integrated monitoring network in a small stream located Dresden, Germany. We further developed an integrated model that incorporates both combined and separate sewer network discharges to evaluate their impact on the stream water quality. By integrating long-term, high-resolution monitoring with catchment-scale modelling, this study offers new insights into the export and dynamics of TSS and PBCs transport in urbanised catchments. Our findings highlight challenges and opportunities related to modelling PBCs with an integrated approach, showing that embracing the complexity of real-world settings is necessary to support the development of management alternatives to reduce the export of pollutants.