Wide-scope screening of micropollutants in stormwater ponds within Swedish urban catchments

Stormwater refers to the resulting water from precipitation events. In urbanized areas, impervious surfaces result in an increased runoff and, consequently, mobilize pollutants occurring in urban environments to freshwater bodies. Stormwater ponds function as a treatment step of the water before it enters the recipient water body. However, their efficiency to remediate organic micropollutants remains largely unknown. Hence, there is a need to explore the ability of these man-made barriers to remediate organic micropollutants. In this work, we have investigated both influent and effluent water streams from two stormwater ponds during distinct hydrological events to assess their contribution to pollution transport by means of wide-scope screening of organic micropollutants. Several chemicals have been detected. The observed differences in the chemical profile in samples from different ponds highlighted that the activities in the catchment area heavily impacted the composition of the stormwater. Unexpectedly, the chemical profiles of the stormwater during dry and rainy periods were found to be comparable. Additionally, increased contamination was detected in effluent stormwater, indicating poor treatment and the potential redissolution of previously retained chemicals, highlighting the need for better treatment and remediation strategies in man-made stormwater ponds to ensure sustainability of recipient water bodies.