Most European cities have wastewater treatment plants in place, securing thus adequate protection of the aquatic environment. Small communities, however, with a population under 2000, are still far from meeting effluent requirements. The “International symposium on constructed wetlands & small decentralized wastewater treatment plants” ISCW2019, that took place in Patras, Greece, on 29th-31st August 2019, had as a goal to bring together all stakeholders (academicians, local government and technology developers) in an effort to assess the current state of the art in this important environmental issue. The mandate of Circular Economy implies a special interest in the valorization of resources. Thus water reuse and valorization of the generated biomass, e.g. in constructed wetlands are also important issues. Finally, the fate of nutrients and emerging pollutants in small and decentralized wastewater treatment systems is also an important concern.

The Symposium was organized in the frame of the “DOMUS-CW” project, funded by the INTERREG BALKANMED programme, with the kind support of the Hellenic Water Association (HWA).

The conference topics were:

• Natural wastewater treatment systems
• Decentralized wastewater treatment plants
• Smart autonomous systems
• Wastewater quality assessment
• Toxicological Assessment
• Resources and energy recovery from effluents
• Biomass valorization
• Modelling
• Sustainability Assessment
• Role of Plants and Algae
• Legislation and policy