Reshaping water management in today’s and tomorrow’s urban areas: why taking care of micropollutants?

This study examines the challenges of urban water management, focusing on micropollutants in increasingly interconnected water systems. While integrating groundwater, stormwater, and treated wastewater improves sustainability, it also raises contamination risks. Milan serves as a case study to assess the effects of groundwater use for energy, stormwater and wastewater separation, and indirect wastewater reuse for irrigation. These strategies create new pathways for pollutants like PFAS (PFOA, PFOS) and PAHs (pyrene), exacerbated by climate change. An integrated model simulated different scenarios, considering seasonal variations and climate-driven changes. Key findings include: (i) groundwater discharge introduces high PFAS levels into urban canals; (ii) stormwater separation reduces wastewater treatment loads but increases PAH pollution; (iii) climate change intensifies micropollutant mobility, heightening contamination risks. Results show chronic PFAS levels exceeding environmental quality standards and acute pyrene risks in high-rainfall scenarios. Effective mitigation requires groundwater treatment prior to discharge in surface recipient, improved stormwater management, and regulatory enhancements to ensure sustainable urban water systems.