Water_2020 brings together leading professionals working on complementary areas of wastewater treatment (WWT) at Research Institutions, Industries and Water Agencies. The Action will tackle current challenges of WWT, which apart from generating high quality water and sludge, must incorporate issues as resource recovery, energy, odours, greenhouse gases, emerging contaminants, economical efficiency and social acceptance. The aim is to face innovation in wastewater treatment from a holistic point of view, in which technological, environmental, energetic, economic and social factors are included.